Distributions of nerve and muscle fibre types in locust jumping muscle.

Muscle fibres of the locust extensor tibiae (jumping muscle) were examined by interference microscopy and by electron microscopy. The electrical responses of single fibres and the mechanical responses of bundles or selected regions to the nerve fibres were examined. Four axons innervate the muscle: fast (FETi), slow (SETi), common inhibitor (CI) and dorsal unpaired median (DUMETi). Their distributions were examined by combined electrophysiological tracing and EM sectioning. The mean diameter of muscle fibres in different regions varies from 40 to 140 micrometer and is related to the local leg thickness rather than muscle fibre type. The fine structure of a fibre is related to its innervation. Fibres innervated by FETi but not SETi are of fast type ultrastructurally. Fibres innervated by SETi but not by FETi are of slow type ultrastructurally. Fibres innervated by both axons are generally intermediate between the extremes though more nearly of fast type than slow. Distal slow muscle fibres have much slower relaxation rates than do proximal ones. The most proximal bundles are of mixed muscle fibre type. There is an abrupt transition from a mixed population to homogeneous fast type, in the muscle units immediately distal to the most proximal bundles. This transition is associated with the presence of DUMETi terminals on some of the fibres distal to the transition point. There are no SETi endings on these same fibres. Fibres innervated by both SETi and FETi are scattered throughout the leg, but are commonest in the dorsal bundles. The percentage of these increases progressively passing distally. The most distal muscle fibres are innervated by SETi but not by FETi. It is concluded that different regions of the muscle will play different roles functionally since they are differentially sensitive to the pattern of SETi discharge.


Factors affecting glomerular function in the pacific hagfish Eptatretus stouti (Lockington).

Single glomerulus filtration rate in Eptatretus stouti averaged 20.3+/-2.13 (S.E.M.) nl min(-1). Single glomerulus glomerular filtration rate (GFR) could be correlated with arterial pressure when arterial pressure exceeded about 4 cm H2O. Glomerular filtration was affected by postglomerular resistance brought about by alteration of the volume of urinary spaces. Filtration undoubtedly plays a role in glomerulus function. However, average colloid osmotic pressure (COP) of the plasma is almost double the average hydrostatic pressure in the segmental arteries serving the glomeruli. The COP of glomerular fluid is essentially nil, therefore it is difficult to see how pressure filtration alone can account for primary urine formation. When single glomeruli were perfused with colloid-containing Ringer at pressures within the normal range of blood pressures, GFR was within the normal range. GFR was related inversely to the colloid osmotic pressure of the perfusion Ringer. Colloid entered the urine during perfusion. However, in only a few instances did this result in conditions favourable to pressure filtration. To assess the role of active processes in glomerular filtration, chemical inhibitors were added to the perfusion Ringer. Amiloride, acetazolamide, cyanide, 2-deoxy-D-glucose, iodoacetate and ethacrynic acid were without marked effect on glomerular filtration. Ouabain and dinitrophenol markedly reduced GFR; inhibition was probably not due to indirect effects upon the renal vasculature.


Intersegmental reflex coordination by a single joint receptor organ (CB) in rock lobster walking legs.

In the decapod Crustacea, Palinurus vulgaris and Fasus lalandii, the reflex influences of one particular proprioceptor organ, the coxo-basal chordotonal organ (CB), on all the muscles operating the proximal and distal joints of the same leg, have been analysed. The distal end of CB was clamped in fine forceps mounted on a servo-controlled stretcher, and CB length changes of 2 mm were applied. Motor unit activity of the different muscles was recorded as electromyograms (EMGs). 1. Two types of proprioceptive reflex evoked by CB length changes have been investigated: (a) resistance reflexes of the two levator and two depressor muscles of the same leg segment, the coxopodite, i.e. 'intrasegmental reflexes', (b) 'intersegmental reflexes' induced in the muscles operating the proximal (T-C) joint of the same leg, and in all eight muscles of the limb segments distat to CB. 2. Both levator muscles respond reflexly to imposed CB stretch (which normally occurs with limb 'depression'), while both depressors respond during CB shortening (or passive "elevation" of the leg). 3. Intersegmentally CB stretch reflexly activates the M-C extensor muscle, and sometimes facilitates the T-C remotor and C-P bender muscles. Shortening of the single CB organ of a leg excites one or two tonic motor units of the T-C promotor and M-C flexor muscles, and also facilitates the remotor, I-M reductor, and the single stretcher-opener excitatory motoneurone. 4. Some of the muscles, particularly the M-C flexor and extensor muscles, are also influenced intersegmentally by the resting length of CB, usually but not invariably in the same direction as for the corresponding dynamic reflexes. The role of the CB chordotonal organ is discussed, with particular consideration of its intersegmental reflex influence on the posture of the entire leg, and on the more complex motor behaviour of locomotion, where it may be specially significant in coordination of the limb in lateral walking. A complex picture of both tonic and dynamic, inra- and intersegmental reflex regulation of the positions and movements of the limb segments, thus emerges.


Intersegmental reflex actions from a joint sensory organ (CB) to a muscle receptor (MCO) in decapod crustacean limbs.

In the walking legs of decapod crustaceans, intersegmental reflex actions originate from various joint proprioceptors. The activity of the 'accessory flexor' (AF) muscle, which with the myochordotonal organ (MCO) constitutes a muscle proprioceptor for the mero-carpopodite (M-C) joint, is modulated by the sensory discharge of a joint receptor (CB chordotonal organ) for the more proximal, coxo-basal (C-B) joint. Selective mechanical stimulation of the CB organ also reflexly modifies the motor activities of the main M-C flexor and extensor muscles (recorded as EMGs). 1. Dynamic CB stretch (as would occur during a dorso-ventral C-B movement - i.e. 'depression' of the limb) stimulates motor discharge to the M-C extensor muscle, while dynamic release of CB (as during a ventrodorsal C-B movement - or leg 'elevation') excites the accessory flexor as well as the main flexor muscle. 2. Successive M-C muscle responses to repetitive sinusoidal changes of CB length differ quantitatively according to the direction (stretch or release) of the first CB movement, in some cases increasing but more commonly 'adapting' with repetition. 3. Reflex discharge frequencies of the extensor, flexor and accessory flexor motoneurones increase with velocity of CB movement. 4. Eye illumination, and spontaneous or other sources of increased central excitability, generally increase the CB reflex drive to the flexor and accessory flexor muscles and, in parallel, decrease the reflex action on the extensor muscle. The results are discussed in terms of the role of proprioceptive reflexes in intersegmental co-ordination of the leg joints. In particular the significance of the reflex regulation of the myochordotonal receptors, and thereby the gain of the M-C resistance reflexes, is considered in the light of the observed 'co-activation' of main flexor and receptor muscle motoneurones.


On the respiration of Torpedo marmorata.

1. The oxygen consumption of resting Torpedo marmorata was measured using three different methods. The results indicate that this species has a much lower oxygen consumption than other elasmobranchs of comparable size. 2. The gills are ventilated by a mechanism similar to that of other rays, but a relatively small spiracular opening seems to be associated with a more important role of the oro-branchial pump. During hypoxia there is a marked increase in both frequency and amplitude of the ventilatory movements. 3. The frequency of the heart beat is low and shows little change during hypoxia, except under extreme conditions when bradycardia occurs. 4. In some individuals, coupling between cardiac and ventilatory pumps is relatively low but seems to increase at lower ventilatory frequencies and when the ratio between the ventilatory and cardiac frequencies is a whole number. 5. Extreme hypoxia can be withstood for many hours but eventually the ventilatory rhythm ceases; it does not recommence immediately following a rise in ambient oxygen tension. 6. The blood has a low oxygen-carrying capacity and a high affinity. 7. The surface area of the gills is smaller than that of other species that have been investigated, but the quantity of oxygen transferred/unit surface area is similar to that known for other species. 8. It is concluded that Torpedo is a sluggish fish adapted to conditions of low oxygen, but the conditions under which this occurs remain to be determined.


Distribution of a major connective tissue protein, fibronectin, in normal human tissues.

Fibronectin is a major surface-associated glycoprotein of cultured fibroblasts and it is also present in human plasma. Antiserum specific for human fibronectin was used to study the distribution of fibronectin in normal adult human tissues. The protein was detected (a) characteristically in various basement membranes including capillary walls: (b) around individual smooth muscle cells and in the sarcolemma of striated muscle fibers; and (c) in the stroma of lymphatic tissue and as thin fibers in loose connective tissue. The distribution of fibronectin was distinct from that of collagen and elastic fibers, but was very similar to reticulin, as demonstrated by conventional histological staining. The results indicate that fibronectin is a major component of connective tissue matrix. The distribution also indicates that most types of adherent cells abut fibronectin-containing structures. This supports the possible role of fibronectin in cell-cell and cell-matrix interactions in tissues.


Acute phase reactants ceruloplasmin and haptoglobin and their relationship to plasma prostaglandins in rabbits bearing the VS2 carcinoma.

Results of previous studies have shown that the VX2 carcinoma in rabbits synthesizes large amounts of prostaglandin E2 (PGE2). PGE2 secreted by the tumor is rapidly metabolized and can be measured in plasma as the metabolite 13,14-dihydro-15-keto-PGE2 (PGE2-M). We have previously proposed that the hypercalcemia that occurs in rabbits bearing the VX2 carcinoma is due to excessive secretion of PGE2 by the tumor and its subsequent action on the skeleton as a bone resorption-stimulating factor. In the course of these studies, we noted that the plasma of rabbits bearing the VS2 carcinoma became blue about 1 wk after tumor implantation. The intensity of the color increased markedly thereafter. We therefore measured ceruloplasmin in plasma by both chemical and immunological assay methods. Plasma ceruloplasmin and PGE2-M rose in parallel (within 7-10 days) and preceded by 7-10 days the development of hypercalcemia. 2 wk after tumor implantation, plasma PGE2-M and ceruloplasmin had risen about 20- and 6-fold, respectively, while the rise in plasma calcium was just beginning. Indomethacin, an inhibitor of prostaglandin synthesis, given from the time of tumor implantation prevented completely the hypercalcemia and largely inhibited the rise in ceruloplasmin. When given after hyperprostaglandinemia had developed, indomethacin produced a fall in both PGE2-M and ceruloplasmin. A rise in plasma haptoglobin concentrations similar to that seen for ceruloplasmin was also observed. No changes in plasma albumin concentrations occurred. We conclude that the acute phase reactants ceruloplasmin and haptoglobin rise rapidly in the plasma of rabbits bearing the VX2 carcinoma, and that this increase is related to arachidonic acid metabolism in these animals. It is possible that arachidonic acid metabolites also play a role in the elevations of these two plasma proteins observed in certain patients with malignant tumors.


Proliferative capacity of mouse peritoneal macrophages in vitro.

Thioglycolate-stimulated mouse peritoneal macrophages cultured in the presence of macrophage growth factor (MGF) will continue to proliferate when they are removed from culture dishes with the local anesthetic lidocaine and subcultured. The number of times the cells can be subcultured and remain in a proliferative state is dependent on the number of previous cell divisions. One precursor cell (colony-forming cell) yields about 2.6 X 10(4) daughter cells. When MGF is removed from actively proliferating macrophages, they leave the cell cycle and enter a "resting" condition. When MGF is readded, cells reenter the cell cycle and proliferate with the same doubling time as if MGF had not been removed. Membrane 5'-nucleotidase activity was used as a probe to identify the state of macrophage activation. Proliferating macrophage populations had significantly higher enzyme levels than stimulated macrophages cultured without MGF. These enzymes levels were, however, lower than those found for resident (unstimulated) macrophages.


Specific protease deficiency in polymorphonuclear leukocytes of Chédiak-Higashi syndrome and beige mice.

Peripheral blood leukocytes of three patients with Chédiak-Higashi syndrome (CHS) contained very low or undetectable levels of elastase, the major neutral protease in these cells. Likewise, peritoneal exudate leukocytes of beige mice (the murine counterpart of CHS) contained correspondingly reduced levels of their major neutral protease, a serine enzyme of mol wt 27,000. The elastase deficiency in CHS polymorphonuclear leukocytes might account in part for the high incidence of infections in these patients.


Anti-viral activity induced by culturing lymphocytes with tumor-derived or virus-transformed cells. Identification of the anti-viral activity as interferon and characterization of the human effector lymphocyte subpopulation.

A viral inhibitor(s) is released in the supernate of mixed cultures containing human or mouse lymphocytes and cells from certain lines. The inhibitor is active against a variety of unrelated viruses and is a protein that is not toxic for cells. It does not inactivate viruses directly, but inhibits viral replication through an intracellular mechanism that involves synthesis by the cells of both RNA and protein. These characteristics identify the inhibitor as an interferon. The anti-viral activity is contained in at least two molecular species, of approximately 25,000 and 45,000 daltons, respectively. In addition to the anti-viral activity, the supernates of the mixed cultures display an anti-cellular activity, the inhibition of DNA synthesis and of cell multiplication. The anti-viral and the anti-cellular activities are positively correlated in supernates from various cultures and in partially purified preparations. The human cell population responsible for interferon production is composed mainly of Fc-receptor positive, surface immunoglobulin negative, non-T-cell lymphocytes. The ability of certain cell lines to induce interferon seems to be preferentially associated with tumor origin or with in vitro transformation by certain viruses (Epstein-Barr virus, murine sarcoma virus).


Anti-viral activity induced by culturing lymphocytes with tumor-derived or virus-transformed cells. Enhancement of human natural killer cell activity by interferon and antagonistic inhibition of susceptibility of target cells to lysis.

Interferon, induced in lymphocytes either with viruses or cell lines, increases severalfold the natural cytotoxicity of human lymphocytes on target cell lines. Cell separation experiments support the hypothesis that interferon enhances the activity of natural killer cells rather than generating a new population of effector cells. In mixed culture of lymphocytes and cell lines in which endogenous interferon is produced, interferon mediates an enhancement of cytotoxicity that represents up to 70-90% of the observed cytotoxicity. The effect of interferon on target cells is antagonistic to the effect on the lymphocytes: the susceptibility to cell-mediated lysis of various cells upon pretreatment with interferon is decreased and in some cases almost completely suppressed. Interferon renders target cells resistant to natural killer cells acting by an intracellular mechanism which requires RNA and protein synthesis. While normal fibroblasts are protected, virus-infected cells and most tumor cells usually are not protected by interferon. Interferon by stimulating very efficient nonspecific cytotoxic cells and by protecting at the same time normal cells from lysis, might render the natural killer cell system an inducible selective defense mechanism against tumor and virus-infected cells.


[Intestinal carbohydrate absorption--correlation between morphology and biochemistry (author's transl)].

After a short description of the morphology of the small intestinal mucosa the physiological processes of carbohydrate digestion and absorption are discussed. While starch is hydrolyzed by amylase in the lumen of the duodenum, the disaccharide hydrolysis does not take place in the intestinal lumen, but at the brush border membrane of the enterocyte. The liberated monosaccharides are--at least in part--absorbed by a specific active transport system. This mechanism is different from those which are responsible for the active transport of primary monosaccharides, i.e. monosaccharides which do not result from oligosaccharide hydrolysis. The exit process for monosaccharides out of the enterocyte into the extracellular space occurs by "facilitated diffusion". Passage through "fenestrated" capillaries is discussed as a possible mechanism for the entry of monosaccharides into the blood vessel system.


A specific detection method for multiple forms of cystine aminopeptidase (oxytocinase-isoenzymes) after polyacrylamide gel electrophoresis.

A simple and specific detection method for multiple forms of cystine aminopeptidase (oxytocinase-isoenzymes) in pregnancy serum is described using S-benzyl-L-nitroanilide as substrate. The relative distribution of both cystine aminopeptidase isoenzymes at different stages of pregnancy is given.


[Kinetic immunological-turbidimetric determination of C-3 protein with a fast analyzer (author's transl)].

A new immunological-turbidimetric method is described for the quantitative determination of individual proteins. It is based on initial rate analysis with fixed time kinetics. The optimal conditions for the analysis of C-3 protein are described, with respect to buffer composition, reaction time, the time interval for measurement of the initial rate, and the concentrations of antigen and antibody. With these optimised, standardised conditions, it is possible to obtain results for 29 samples in 20 seconds, using a reaction time of deltaA/15 seconds. The method is relatively accurate with a day to day variation coefficient of 4.3 for C-3 concentrations of 217.5 mg/l, and 6.4 for concentrations of 435 mg/l. It is therefore suitable for the clinical chemical laboratory. A detailed comparison of this with other methods, and its use in the measurement of patients' sera will be presented elsewhere.


Electrically silent anion transport through lipid bilayer membranes containing a long-chain secondary amine.

The permeability properties of planar lipid bilayers made from egg lecithin, n-decane and a long-chain secondary amine (n-lauryl [trialkylmethyl]amine) are described. Membranes containing the secondary amine show halide selectivity and high conductance at pH less than 6, as estimated by measurements of zero-current potentials generated by NaBr activity gradients. In the absence of halide ions, the membranes show H+ selectivity, although the total membrane conductance is relatively low. In 0.1 M NaBr both the membrane conductance (Gm) and the Br- self-exchange flux (JBr) are proportional to H+ concentration over the pH range of 7 to 4, and both JBr and Gm saturate at pH less than 4. However, JBr is always more than 100 times the flux predicted from Gm and the transference number for Br-. Thus, greater than 99% of the observed (tracer) flux is electrically silent and is not a Br2 or HBrO flux because the reducing agent, S2O3=, has no effect on JBr. At pH 7, JBr is proportional to Br- concentration over the range of 1-340 mM, with no sign of saturation kinetics. Both urea and sulfate tracer permeabilities are low and are unaffected by pH. The results can be explained by a model in which the secondary amine behaves as a monovalent, titratable carrier which exists in three chemical forms (C, CH+, and CHBr). Br- crosses the membrane primarily as the neurtal complex (CHBr). The positively charged carrier (CH+) crosses the membrane slowly compared to CHBr, but CH+ is the principal charge carrier in the membrane. At neurtal pH greater than 99% of the amine is in the nonfunctional form (C), which can be converted to CH+ or CHBr by increasing the H+ or Br- concentrations. The permeability properties of these lipid bilayers resemble in many respects the permeability properties of red cell membranes.


Removal of sodium channel inactivation in squid giant axons by n-bromoacetamide.

The group-specific protein reagents, N-bromacetamide (NBA) and N-bromosuccinimide (NBS), modify sodium channel gating when perfused inside squid axons. The normal fast inactivation of sodium channels is irreversibly destroyed by 1 mM NBA or NBS near neutral pH. NBA apparently exhibits an all-or-none destruction of the inactivation process at the single channel level in a manner similar to internal perfusion of Pronase. Despite the complete removal of inactivation by NBA, the voltage-dependent activation of sodium channels remains unaltered as determined by (a) sodium current turn-on kinetics, (b) sodium tail current kinetics, (c) voltage dependence of steady-state activation, and (d) sensitivity of sodium channels to external calcium concentration. NBA and NBS, which can cleave peptide bonds only at tryptophan, tyrosine, or histidine residues and can oxidize sulfur-containing amino acids, were directly compared with regard to effects on sodium inactivation to several other reagents exhibiting overlapping protein reactivity spectra. N-acetylimidazole, a tyrosine-specific reagent, was the only other compound examined capable of partially mimicking NBA. Our results are consistent with recent models of sodium inactivation and support the involvement of a tyrosine residue in the inactivation gating structure of the sodium channel.


Desensitization onset and recovery at the potassium-depolarized frog neuromuscular junction are voltage sensitive.

The influence of voltage on the time-course of desensitization onset and recovery has been studied at the frog neuromuscular junction. The activation-desensitization sequence was determined from carbachol-induced end-plate currents in potassium-depolarized fibers voltage-clamped either to -40 mV or +40 mV. The time-course of both desensitization onset and recovery developed exponentially, with onset occurring more rapidly than recovery. Desensitization onset was voltage dependent, the onset time constant being 8.3 +/- 1.3 s (11 fibers) at -40 mV and 19.3 +/- 3.4 s (15 fibers) at +40 mV. Recovery from desensitization was also influenced by voltage. The extent of recovery after 2 min was 80.4 +/- 6.3% in those fibers voltage-clamped to -40 mV and 57.4 +/- 3.6% in those fibers voltage-clamped to +40 mV. The voltage dependence of desenistization onset and recovery did not result from a difference in ability to control voltage at these two levels of membrane potential. These results demonstrate that in the potassium-depolarized preparation the processes controlling both desensitization onset and recovery of sensitivity from the desensitivity from the desensitized state are influenced by membrane voltage.


Ionizable groups and conductances of the rod photoreceptor membrane.

The ionizable groups and conductances of the rod plasma membrane were studied by measuring membrane potential and input impedance with micropipettes that were placed in the rod outer segments. Reduction of the pH from 8.0 to 6.8 or from 7.8 to 7.3 resulted in membrane depolarization in the dark from 8.0 to 6.8 or from 7.8 to 7.3 resulted in membrane depolarization in the dark (by 2- 3 mV) and an increased size of the light response (also by 2-3 mV). The dark depolarization was accompanied by and increased resting input impedance (by 11-35 Momega). When the pH was decreased in a perfusate in which Cl(-) was replaced by isethionate, the membrane depolarized. When the pH was decreased in a perfusate in which Na(+) was replaced by choline, an increase of input impedance was observed (11-50 Momega) even though a depolarization did not occur. These results are consistent with the interpretation that the effects of decreased extracellular pH result mainly from a decrease in rod membrane K(+) conductance that is presumably cause by protonation of ionizable groups having a pK(a) between 7.3 and 7.8. Furthermore, from these results and results obtained by using CO(2) and NH(3) to affect specifically the internal pH of the cell, it seems unlikely that altered cytoplasmic [H(+)] is a cytoplasmic messenger for excitation of the rod. When the rods were exposed to perfusate in which Na(+) was replaced by choline, the resting (dark) input impedance increased (by 26 Momega +/- 5 Momega SE), and the light-induced changes in input impedance became undetectable. Replacement of Cl(-) by isethionate had no detectable effect on either the resting input impedance or the light-induced changes in input impedance. These results confirm previous findings that the primary effect of light is to decrease the membrane conductance to Na(+) and show that, if any other changes in conductance occur, they depend upon the change in Na(+) conductance. The results are consistent with the following relative resting conductances of the rod membrane: G(Na(+)) similar to G(K(+)) more than 2-5 G(Cl(-)).


Trypanosoma (Schizotrypanum) dionisii: influence of mouse peritoneal macrophages and calf sera on extracellular growth in vitro at 37 degrees C.

Macrophages and certain batches of sera were essential for extracellular multiplication of Trypanosoma dionisii in vitro in medium 199 with 20% (v/v) calf serum at 37 degrees C. In mixtures of 'good' and 'bad' batches of sera, multiplication increased as the proportion of the former was increased. Mixtures of 'bad' and 'intermediate' sera permitted virtually no growth. Phagocytosis of parasites by macrophages was unaffected by different batches of sera, though reduced in medium 199 alone. Replacement of supernatant medium by medium containing 'bad' serum reduced the macrophage infection rate no more than did transfer to medium containing 'good' serum. Daily addition of medium conditioned by prior contact with macrophages in vitro to cultures of trypanosomes without macrophages resulted in growth at least as good as that in the presence of macrophages. Extracellular replication in medium 199 at 37 degrees C apparently required at least two factors: 'M factor' provided by macrophages, but not required at 28 degrees C; and 'S+ factor' present in some batches of calf serum, essential also at 28 degrees C but not required by intracellular parasites. Some sera appeared to contain an inhibitory 'S- factor'.


Isolation and transduction analysis of temperature-sensitive mutants of Staphylococcus aureus defective in DNA replication.

Four temperature-sensitive mutants of Staphylococcus aureus with defects affecting DNA synthesis have been isolated and partially characterized. They fall into two groups: three have defects either in elongation of DNA or synthesis of its precursors; the fourth has properties inconsistent with a defect in either elongation or initiation. Transduction analysis indicated that the mutation in this fourth mutant is unlinked to the mutations in the other three, which are all clustered on one side of a gene conferrring resistance to novobiocin.


Structural polypeptides of measles virus.

The structural polypeptides of two strains of measles virus grown in Vero cells were analysed in SDS-PAGE slab gels. Six major polypeptides were identified with mol. wt. of 79000, 72000, 60000, 43000, 40000 and 36000. The largest polypeptide was sensitive to trypsin digestion and was the dominant glycosylated polypeptide identified when the virus was grown in medium containing 3H-fucose or 3H-glucosamine or when the virus was treated with galactose oxidase and labelled with 3H-sodium borohydride. It is concluded that the 79000 mol. wt. polypeptide represents the haemagglutinin. Treatment with non-ionic detergent removed this polypeptide and also the 40000 mol. wt. polypeptide from the virus envelope. The 40000 mol. wt. polypeptide is probably associated with haemolysin and cell fusion activities and is analogous to the F1 of paramyxoviruses. A polypeptide of mol. wt. approx. 20000 detected after glycoprotein labelling may represent the F2 of measles virus. The 43000 mol. wt. polypeptide co-migrates with cellular actin and is the only major measles polypeptide that is heavily labelled when the virus is grown on Vero cells prelabelled with 35S-methionine. Thus it may represent cellular actin incorporated into the virus during maturation. The quantity of the 72000 mol. wt. polypeptide relative to the other major polypeptides varied considerably in different virus preparations. The role of the polypeptide could not be defined. By analogy with previously published data the 60000 and 36000 mol. wt. polypeptides are inferred to represent nucleocapsid and membrane proteins, respectively.


Prevention of death in Semliki Forest virus-infected mice by administration of defective-interfering Semliki Forest virus.

Adult mice inoculated with Semliki Forest virus (SFV) were protected from a lethal infection of the central nervous system by intranasal administration of defective-interfering (DI) SFV. DI SFV was prepared by eight passages at high m.o.i. in BHK 21 cells. Mice were treated with unpurified, unconcentrated tissue culture fluid which had been u.v.-irradiated to inactivate the infective virus present. Prevention of death was maximal when the DI virus was administered simultaneously with the infecting inoculum, and under the same conditions multiplication of infective virus in the brains of treated mice was reduced by 10(5)-fold. It was shown that DI SFV was propagated in mouse brains followed intranasal inoculation and it was concluded that protection was brought about through the intrinsic interfering capacity of the DI virus.


Inhibition of African swine fever (ASF virus replication by phosphonoacetic acid.

Phosphonoacetic acid (PAA) inhibits the multiplication of African swine fever (ASF) virus in VERO cells. The observed inhibition of the in vivo DNA synthesis could be related to the in vitro inhibition of a virus-induced DNA polymerase activity present in cytoplasmic extracts from infected VERO cells.


Amino acid requirement of adenovirus multiplication.

The absence from the medium of any of the 13 amino acids essential for cell growth has an inhibiting effect on the multiplication of adenovirus 9-15 and adenovirus I in HeLa cell cultures. The inhibition is accentuated by previous amino acid starvation of the cultures. Whereas with arginine deprivation, the arginine pool inside the cells is at a minimum within 30 min, the cells are assumed to adapt slowly to the new metabolic state, which is characterized by an increased 'turnover' of protein synthesis. With arginine deficiency and in Hanks' BSS some synthesis of virus and capsid proteins takes place. Quantitative and possibly qualitative differences between the influence of the various deficient media were observed. The experiments rule out DNA synthesis as a primary cause of the amino acid deficiency effect. They lead to the hypothesis that arginine deficiency inhibits the formation of an essential protein which is synthesized very late in the infectious cycle under complete MEM.


Integration of adenovirus type 2 DNA in productively infected cells: results of sequential hybridization experiments.

In human KB cells permissively infected with adenovirus type 2, the high mol. wt. forms of virus DNA have been characterized. These size classes of virus DNA sediment at greater than 100S and 40 to 90S in alkaline sucrose density gradients. Considerable evidence from a series of earlier communications supports the notion that the high mol. wt. forms of virus DNA represent virus DNA sequences covalently linked to cellular DNA. 3H-labelled high mol. wt. adenovirus type 2 DNA from productively infected cells can be shown to hybridize to virus DNA fixed to filters. In the present paper we demonstrate that on alkali elution of the DNA from the filters used in the first step of the hybridization experiment, the labelled DNA re-hybridizes to cellular DNA in the second step of a sequential hybridization experiment. The order of performing the two successive hybridization experiments can be reversed and very similar results are obtained. These data provide conclusive evidence for the covalent linkage of virus and cellular DNA sequences in KB cells productively infected with adenovirus type 2.


The meaning of IQ constancy in young retarded children.

In a clinic population of 289 children (nine years of age and under) suspected of developmental delay, it was found that correlations on repeated administrations of the Bayley and/or Stanford-Binet intelligence tests were much higher than in normal children; that the magnitude of the correlations was inversely related to IQ level; that children initially tested under two years of age displayed more IQ change than those tested over the age of two, with girls more likely than boys to show a drop, and the greatest amount of fluctuation occurring the 51-80 range. The IQ constancy of this population has important developmental implications for the retarded: it suggests that they are growing intellectually at a rate proportional to normal children of their own mental rather than chronological age; that they may well have more years of maturation before reaching a plateau; and that educational programs should take into consideration this lengthened learning period.


Sex differences on a measure of self-esteem: theoretical implications.

The hypotheses of this study of sex differences on a measure of self-esteem are as follows: 1) the scales good, nice, generous, pleasant, dependable, honest, and active will group together to form the outer esteem dimension of the semantic differential; 2) the scales strong, leader, powerful, confident, curious, inventive, sharp, and active will group together to form the inner esteem dimension of the semantic differential; 3) males will score significantly higher than females on the inner esteem dimension of the semantic differential; 4) females will score significantly higher than males on the outer esteem dimension of the semantic differential; 5) there will be a significnat difference between the scoring patterns of males and females on the two dimensions of the semantic differential after controlling for the effects of race and social desirability. The sample of 442 sixth through eighth grade students consisted of two subsamples made heterogeneous on race, geographic location, and type of school. The Frnks-Marolla Self-Esteem Semantic Differential and the Lunneborg and Lunneborg Child's Social Desirability Scale were administered. The findings support each of the hypotheses and indicate that there is a significant difference between the sexes on the Franks-Marolla Semantic Differential Measure of Self-Esteem. It is concluded that additional research in self-esteem might specify the meaning of sex differences in esteem by measuring esteem relative to an individual's structural social positions rather than measuring esteem in the general and environmentally nonspecific contexts as advocated by some.


Body image stereotypes: a developmental comparison.

The purpose of this study was to test the hypothesis that temperament judgments associated with different body types were dependent upon sex and age of the respondents. A total of 500 participants, 249 females and 251 males ranging from 6 to 60 years of age, were sampled. Participants were drawn from various civic, educational, institutional, and residential groups in a Southern cosmopolitan city. A paper-pencil instrument consisted of three body silhouettes (representing an ectomorph, mesomorph, and endomorph) and 40 temperament/behavior descriptors. The respondents matched each descriptor with one of the three body types. The results indicated that the descriptors were differentially associated with body types according to age groups but not by sex. The mesomorph was overwhelmingly and consistently viewed as the most positive of the three body types, but was rated somewhat more negatively as the age of the group increased. Participants of ages 6 through 25 rated the endomorph more negatively than the ectomorph, while those of ages 26-40 rates them equally. In contrast, participants over 40 years of age viewed the ectomorph more negatively than the endomorph.


An exploration of antecedents and attributes of androgynous and undifferentiated sex roles.

This study sought to clarify the nature of androgynous (both masculine and feminine) and undifferentiated (neither masculine nor feminine) sex-role outcomes. One inquiry concerned the parent identification patterms most likely associated with androgyny and undifferentiation. ANother inquiry considered differences between the masculinity or femininity of androgynous adolescents and these sex-role behaviors as represented in masculine and feminine adolescents, respectively. Similarly, the sex-role differences for masculine, feminine, and undifferentiated adolescents were investigated. The white, middle-class Ss included 142 male and 193 female college students (average age under 19 years). Parent and S sex-role scores, as well as identification scores, were based upon adjective check list self-descriptions and parent descriptions obtained from the S's. Androgynous males most frequently identified with a nonstereotypic mother combining masculine and feminine qualities, whereas undifferentiated males more often identified with a stereotypically feminine mother (p less than .01). No differences in female identification emerged. Both sexes of androgynous Ss revealed masculine attributes similar to those of masculine Ss but lacked many of the femine qualities of feminine Ss. A blending of sex-role dispositions in androgyny was inferred.


A psychological profile of the transsexual. I. The male.

The present research introduced standardized psychological measurement into the clinical assessment of the male transsexual. Thirty-one males with a presenting complaint of gender dysphoria were carefully screened as to their correspondence with current nosological conceptions of transsexualism, and administered the Derogatis Sexual Functioning Inventory (DSFI) as part of their clinical psychometric work-up. The DSFI is an omnibus self-report scale providing measurement in the primary domains of sexual information, sexual experiences, sexual drive, sexual attitudes, psychological symptoms, affects, gender role definition, and sexual fantasy. Transsexual profiles were contrasted with those of a comparison group of 57 normal heterosexual males. Results of the comparisons revealed the transsexuals to show a significant decrement in accurate sexual information, and a marked reduction in the variety of sexual experiences they have been involved in. They also revealed a reduction in drive levels; however, this was qualified by which indicator of drive was used. Significant elevations in psychological symptoms and dysphoric affect were also noted, particularly of a depressive nature. Gender role definitions were markedly polarized in the feminine direction for male transsexuals, and their fantasy endorsements revealed some of the classic transsexual themes. The ability to develop this quantified and standardized psychological profile is viewed as an important step in accurately assessing the nature of these complex individuals, and developing a more accurate understanding of their condition.


The psychological management and treatment of hospitalized transsexuals.

The findings of this paper are based on a 3-year study at the Gender Identiy Clinic of University Hospitals of Cleveland, involving 16 patients who were sexually revised (SR) from a total of 125 applicants. Three of these patients were provided second-stage surgeries which were begun elsewhere. The paper addresses some of the major problems of the SR patients' pre- and postsurgical experience. Specifically, a) evidence is provided to suggest the existence of a well defined preoperative syndrome which often affects the postoperative course of recovery which may lead to a clinical state of depression; b) the problems and process of the medical team in the treatment of the SR patient are discussed; and c) a modified version of Janis' counseling model for the high risk presurgical patient (to be employed with the preoperative SR patient) is introduced. These important but often neglected topics help us to understand some of the psychiatric management problems in the pre- and postoperative SR patient, while also pointing to some of the difficulties researchers have had in providing follow-up studies with this patient population.


Minnesota Multiphasic Personality Inventory prediction of intellectual changes following cardiac surgery.

One hundred two cardiac surgery patients were tested with the Minnesota Multiphasic Personality Inventory (MMPI) preoperatively and 98 of these patientts (two diet, two were untestable) were tested both pre- and postoperatively with the Wechsler Adult Intelligence Scale, Bender-Gestalt, and the Wechsler Memory Scale. A large number of the patients obtained preoperative "neurotic"-type MMPI profiles. Postoperative deficits in intellectual ability were slight for the group as a whole, however, there was marked within-group variance. The MMPI was not found to be useful as a predictor of postoperative intellectual changes.


Capgras syndrome-a biochemical marker?

Two cased of Capgras syndrome are reported in which platelet monoamine oxidase (MAO) activity is singificantly less than that of 24 psychiatric controls and 39 nonpsychiatric controls. This is the first report of a consistent biochemical abnormality associated with the Capgras phenomenon. Additional evidence is discussed which suggests that psychiatric patients with  Capgras syndrome may belong to a discrete group of behavioral disorders characterized by reduced platelet MAO activity.


Hemodialysis and schizophrenia. A negative report.

A preliminary, uncontrolled study utilizing hemodialysis in the treatment of chronic schizophrenia reported a high success rate. Two patients are presented who had both schizophrenia and chronic renal failure and who underwent intensive, long term hemodialysis with no change in their schizophrenic symptomatology. This negative finding is consistent with other case reports. Retrospective or limited controlled studies based on previous research with false neurotransmitters, serum protein factors, or endorphins in schizophrenia are urged before further patients with normal kidney function are exposed to the risks of hemodialysis.


A rapid behavioral treatment for needle phobics.

A morbid fear of injections and injection paraphernalia can on occasion seriously compromise both the inpatient and outpatient treatment of medical illnesses. Two individuals with a severe needle phobia were treated using participant modeling. In both cases, this very rapid treatment resulted in a remission of symptoms, that in one case persisted at 1 year follow-up post-treatment.


Sociodemographic factors and military psychiatric hospitalization.

This study of race, rank, and psychiatric hospitalization was conducted to provie more information about the impact of social class factors on military inpatient treatment. A retrospective review of the charts of all commissioned officers admitted over a 16-month period along with control groups of airmen and sergeants matche for time of admission was undertaken at a large military training center. Groups were compared on sociodemographic variables (age, race, rank, sex, marital status, length of service, and education background) as well aa clinical variables (referral source, chief complaint, diagnosis, length of stay, and outcome). The implications of briefer hospitalizations for the youngest group of patients (the airmen) are discussed. The over-representation of black enlisted soldiers as psychiatric patients and organizational means of rectifying this situation are discussed.


Treatment of erythrophobia by paradoxical intention.

A 25-year-old male was treated by paradoxical intention for erythrophobia that had been present for 12 years. Severe blushing episodes decreased from 28 during the month preceding treatment to three during treatment; there were never more than two severe blushing episodes per month during the 6-month follow-up. The mean duration of each severe episode was 13 minutes before treatment, 8 minutes during treatment, and varied from 4 to 9 minutes during follow-up. Although this treatment is easy for both the patient and therapist, it is important that the patient be highly motivated. A good relationship with the therapist and the use of humor can enhance the therapeutic efficacy of paradoxical intention.


Life event stress, social support, coping style, and risk of psychological impairment.

The effects of life event stress, coping style, and social support on psychological impairment were examined in a survey of a representative Australian suburban sample (N = 863). Psychological impairment was defined as a score of 4 or more on the 20-item General Health Questionnaire. Life event stress, coping style, and one of the social support variates, crisis support, were related to impairment, significantly decreasing or increasing the risk of being identified as impaired from the total sample frequency of 24 per cent. There was no evidence that coping style or social support became associated by moderating the relationship between life event stress and impairment, but rather because of their independent relationship with psychological impairment.


Social adjustment by self-report in a community sample and in psychiatric outpatients.

Data are presented on social functioning derived from a self-report social adjustment scale (SAS-SR) administered to 774 subjects including a community sample and three psychiatric outpatient populations: acute depressives, alcoholics, and schizophrenics. This self-report scale derives from an interview form and was developed and tested on depressed outpatients. Since its publication, it has been used in populations other than depressives including other psychiatric patients, nonpsychiatric patients, and nonpatients. The purpose of this paper is to make data available to other investigators on results of this self-report social adjustment scale in a broad range of subjects and to describe further the psychometric properties, limitations, and utility of the scale. Findings show that the scale has wide applicability in a range of subjects but that certain cautions should be followed in using it with chronically impaired psychiatric populations who may not be involved in the major roles assessed by the scale.


Treatment environment and patient improvement.

This study investigated the relationship between treatment environment and patient behavior change. The psychosocial environments of eight psychiatric wards were assessed by having patients complete the Ward Atmosphere Scale and by having observers record ongoing social interactions on the ward. These environmental measures were related to behavior change scores taken from staff ratings of patient behavior. Both the patient perceptions of the ward environment and the observational environmental measures displayed significant relationships with behavior change. Patient perceptions of staff control and of staff acceptance of anger were found to be important environmental dimensions for patient improvement. In addition, wards having more patient-staff interaction displayed more patient improvement.


Sexual behavior correlates of female orgasm and marital happiness.

The present study was designed to investigate sexual behavior correlates of marital happiness and female orgasm. Forty-eight female students of Baylor University who were 20 to 35 years old and had been married at least 2 years participated in the survey. A specially compiled 131-item marital relations questionnaire provided data for an intercorrelational analysis. Marital happiness, fidelity, and experience of orgasm correlated with certain specific sexual behaviors. These variables were related also to dissatisfaction with marital sex, which is consistent with previous research. However, when dissatisfaction resulting from performing less desired sexual acts was separated from dissatisfaction resulting from not performing desired sexual acts, the correlations differed, often markedly. Thus, the data suggest that unitary measures of dissatisfaction with marital sex may obscure meaningful differences. Also, information was obtained concerning the orgasmic and multiple orgasmic experience of the women, their extramartial experience, and their relative use of and preference for various intercourse positions and noncoital sexual activities.


Covert outpatient drug abuse. Incidence and therapist recognition.

One hundred ninety-five consecutive psychiatric outpatients were surveyed for covert drug abuse by a standardized technique for determining opiates, cocaine, barbiturates, and amphetamines in urine samples. On the basis of demographic variables, diagnostic information, and treatment course, patterns of abuse were defined for the 13.3 per cent with positive test results. Covert abusers demonstrated a higher incidence of adverse drug reactions and a less favorable therapy course than controls. Covert abuse was meaningfuly related to misdiagnosis, management problems, and therapist's response. Demographic variables and patient reports of previous abuse were not found to be reliable predicators of covert drug abuse. Urine screening for drug use is recommended as an aid to proper diagnosis of psychiatric outpatients that present diagnostic questions.


An investigation of weights in the parents of anorexia nervosa patients.

Although large series studies of anorexia nervosa families have found a greater than expected occurrence of anorexia nervosa in family members, there are no reports of the anorectic's parents' weights during the time of the patient's illness. An unusual degree of weight aberrations present in the parents at the time of the patient's illness could represent both a genetic and noxious environmental influence for the development of anorexia nervosa. In order to examine the possibility that weight aberrations may be more frequent in anorectic patients' parents, we obtained height and weight measurements from the parents of 30 anorexia nervosa patients. The parents were compared with 30 control families in which the father was matched for age, level of education, occupation, and salary to the patient's father. Matching the control group for socioeconomic status was necessary since previous studies have shown a relationship between socioeconomic status and weight. An analysis of covariance showed no difference between the weight of the patient and control parents, although a significant relationship between educational level and weight was present.


Marijuana effects on associations to novel stimuli.

Sixteen college-educated male subjects were given an object description task during placebo conditions and while intoxicated with marijuana extract cookies calibrated to 0.3 mg/kg delta-9-tetrahydrocannabinol, a dose within the range of usual social use. The task was scored for fluency, flexibility, elaboration, and uniqueness, all of which represent associational thinking and are considered to be components of creativity. Marijuana did not enhance any of these measures.


The effects of amitriptyline and lithium on a patient with 48-hour recurrent depressions.

A 61-year-old man with a 5-year history of 48-hour mood swing cycles--1 day depressed, 1-day euthymic--was treated with medications in a double blind trial. Placebo had no effect on his cycles, amitriptyline lessened the amplitude of depression on "bad days" but did not effect the 48-hour periodicity, whereas lithium carbonate therapy terminated both affective symptoms and the cycle itself. After several months on lithium, the patient discontinued the drug, but neither symptoms nor cycles returned. Forty-eight-hour affective cycles are unusual, and this patient's response to lithium is particularly striking.


The effect of thyroid hormones on rat pineal indoleamine metabolism in vitro.

The effect of TSH, triiodothyronine (T3) and thyroxine (T4) on basic and noradrenaline (NA)-induced indoleamine metabolism was investigated in rat pineal culture based on the observation that, under the experimental system used, melatonin is formed from its amino acid precursor tryptophan. When added to the culture medium, alone or in the presence of NA, TSH in dosages of 5 and 20 mU had no significant effect on pineal tryptophan metabolism.T4 and 2.5 microgram increased the melatonin concentration and, in the presence of NA 10(-4) M, also induced an increase in N-acetylserotonin (NAS). T3, already at a dosage as low as 0.25 microgram enhanced the melatonin concentration, while 2.5 microgram produced significant increases in concentrations of all pineal indoleamines measured. The latter dosage of T3 also enhanced the NA-stimulated NAS. On adding larger quantities of T4 or T3 to the medium none of the changes encountered with the lower dosages could be seen. The results obtained may suggest a direct positive feedback between the thyroid and pineal glands.


Direct evidence of acetylcholine releasing effect of serotonin in the Auerbach plexus.

The mode of action of serotonin on isolated longitudinal muscle strip with attached Auerbach plexus and on whole ileum preparation has been studied. Atropine, tetrodoxtoxin, morphine and alpha-adrenoceptor stimulants inhibited the contractions of the strips and whole ileum in response to serotonin. In the presence of atropine (2 X 10(-8) M) at 9 times higher concentration of serotonin was needed to produce the same contraction of the ileum as in control experiments. These facts indicate that the contractile effect of serotonin on the longitudinal muscle of ileum might be mediated via a cholinergic pathway. Direct evidence has also been provided that serotonin is capable of releasing acetylcholine from the Auerbach plexus. It is very likely that serotonin stimulates ganglion cells, which in fact leads to firing and, consequently, to an increase of acetylcholine release from the nerve terminals.


Plasma pituitary hormones in patients with Parkinson's disease treated with bromocriptine.

Bromocriptine was used for Parkinson's disease in 15 patients for 20 weeks. Immunoreactive plasma lutrophin (LH), follitrophin (FSH), prolactin, and somatotrophin (GH, growth hormone) concentrations were analysed before and during the treatment. Plasma prolactin levels were very markedly reduced during treatment. Plasma lutrophin levels were increased significantly in female patients, but not in male patients. No changes were noticed in follitrophin levels, but plasma somatotrophin levels were reduced during treatment. No correlations were found between the degree of clinical response and changes in plasma gonadotrophin and somatotrophin. This suggests that the effects of bromocriptine on extrapyramidal and neuroendocrine dopaminergic neurones are unrelated. We suggest careful and frequent controls of neuroendocrine secretion patterns in patients with Parkinson's disease who are treated with high doses of dopamine receptor stimulators, since the response of some pituitary hormones to bromocriptine are very marked.


Increased effect of apomorphine on homovanillic acid in rats terminated from chronic haloperidol.

Rats who were administered apomorphine seven days after termination of chronic treatment with haloperidol had significantly (59%) lower level of brain HVA than saline control rats. This finding is consistent with the behavioral evidence suggesting supersensitivity of post-synaptic dopamine receptors after termination of chronic haloperidol.


Plasma dopamine-beta-hydroxylase and erythrocyte acetylcholinesterase in a group of patients with Parkinson disease.

In a group of patients with Parkinson disease there was no difference in plasma DBH activity between cases treated with L-Dopa and not treated. These patients tend to have an elevated activity of erythrocyte AChE.


The emetic action of L-dopa and its effect on the swallowing reflex in the cat.

In adults cats anesthetized with urethane it was shown that facilitation of reflexly-induced swallowing by dopaminomimetics is caused by a central action independent of the emetic of such drugs. It is suggested that this modulatory influence is mediated by dopamine receptors associated with the amygdala and ventral basal striatum.


Analysis of evoked lumbosacral potentials in man.

Surface electrodes have been used to record potentials evoked in the lumbosacral region of 15 healthy volunteers after tibial nerve stimulation. By monitoring the M waves and H reflexes in the triceps surae muslces and by comparing the responses recorded over the roots with those over the lower cord, it was possible to identify the neural substrates responsible for several of the components in the responses. The findings are compared with those of previous studies in man and in other mammalian preparations.


Growing fractures of the skull.

Tne cases of growing fractures seen in the last 10 years are presented. Six of the patients sustained their injury within the first six months of life. The defects formed rapidly, several within two or three months after injury. There was enlargement of the defect in only one case after the date of discovery. Although the defects involved the parietal bone most commonly, in four out of 10 the lesion crossed either the coronal or the lambdoid suture. The edges of the defects were usually thickened; in some areas they were saucer-shaped but in two cases there was erosion of the outer table of the skull at a distance from the margin of the defect, the erosion being related to an extracranial fluid-filled cavity in continuity with a porencephalic cyst. The ipsilateral ventricle was usually dilated and in a number of cases was associated with a porencephalic cyst. In no case was a "leptomeningeal cyst" found beneath the defect at operation. A detailed review confirms many of the findings previously described but suggests that the pathology of the condition is still not fully understood. Computed tomography, undertaken in one case, appears to be the examination of choice. Further light may be thrown on the pathogenesis of this condition by the use of intracystic, intrathecal, and intraventricular water-soluble contrast media.


Tension pneumocephalus complicating ventriculoperitoneal shunt for cerebrospinal fluid rhinorrhoea: case report.

A case of spontaneous nontraumatic cerebrospinal fluid rhinorrhoea secondary to aqueductal stenosis is reported. The patient required direct repair of the fistula after the insertion of a ventriculoperitoneal shunt for aqueductal stenosis. We emphasise an unusual complication of tension pneumocephalus in a case where the shunt patency had been substantiated. Intracranial pressure fall due to the siphon effect in the ventriculoperitoneal shunt tubing in the erect position might be responsible for ingress of an excessive amount of air.


Influence of dietary myoinositol on nerve conduction and inositol phospholipids in normal and diabetic rats.

Observations have been made on motor conduction velocity in the tibial nerve of rats given 35% myoinositol in the diet. Comparison between the values before and with up to nine weeks of dosing revealed no alteration in conduction velocity. In such animals, the free myoinositol content in the sciatic nerve was increased; there was no detectable alteration in the lipid inositol concentration. In a second series of experiments, tibial motor nerve conduction velocity in rats with streptozotocin-induced diabetes was compared with conduction velocity in diabetic animals given 1% supplementary dietary myoinositol, and with a control group of nondiabetic rats. Conduction velocity was reduced in the diabetic animals, but no influence from the added dietary myoinositol was detected. No statistically significantly difference in sciatic nerve myoinositol was demonstrated, but the sorbitol and fructose concentrations were increased. Those animals fed the myoinositol supplement had a significantly lower lipid inositol content. The significance of these findings is discussed.


Systemic vascular responses to increased intracranial pressure. 3. Effects of individual balloon inflations on intracranial pressure and the systemic circulation.

The effects of discrete increases in the volume of an artificial space-occupying lesion on intracranial pressures and the systemic circulation were studied in six anaesthetised and artificially ventilated dogs. Each increase in volume, accompanied by an increase in supratentorial intracranial pressure, a decrease in supratentorial perfusion pressure, and an increase in transtentorial pressure gradient, induced alterations in the systemic circulation. There were a decrease in heart rate, marked alterations in the arrhythmia index, and increases in stroke volume and systemic vascular resistance. A period of transient systemic hypertension was noted to accompany each discrete increase in intracranial pressure.


CSF hydrodynamic studies in man. 2 . Normal hydrodynamic variables related to CSF pressure and flow.

With the patient in the supine position, the subarachnoidal space was infused with artificial CSF at several constant pressure levels. The resulting flow of liquid was recorded. By draining CSF at a low pressure the CSF production rate was determined. Normal values are given and discussed for (1) the resting pressure, (2) the conductance of the CSF outflow pathways, (3) the formation rate of CSF, (4) the pressure difference across the CSF outflow pathways, and (5) the sagittal sinus pressure. None of the variables showed any age dependence, nor was there any sex difference.


Language laterality assessed by unilateral ECT and dichotic monitoring.

A dichotic monitoring test for the lateralisation of speech dominance was compared with testing for dysphasia after unilateral electroconvulsive therapy to each side of the head in 31 patients, and the intracarotid amylobarbitone test in four epileptic patients. Twenty-eight patients shown to be left speech dominant also showed right ear advantages in the dichotic test. Four of the five right speech dominant patients showed left ear advantages. Two patients with bilateral speech representation showed nonsignificant ear asymmetries. The noninvasive dichotic monitoring task is quick and simple and produces large mean ear advantages (14 to 25%) in normal subjects as well as patients.


Clinical aspects of spasmodic dysphonia.

The clinical features of 12 patients with spasmodic dysphonia are described. In 11 patients, the voice was strained, harsh, tight, and tremulous, and was low in volume and pitch. Speech, which was sometimes barely intelligible, was interrupted by irregular stoppages and catches of the voice; it required considerable effort, and was accompanied by facial grimacing. The dysphonia was part of a more widespread neurological disorder (idiopathic torsion dystonia) in one case, while it coexisted with blepharospasm in another, and with postural tremor in two. There was a buccolingual hyskinesia in another of these 11 patients, but this may have been related to her previous drug regime. In the twelfth patient, who had a familial tremor, the voice was characterised by marked breathiness, with intermittent aphonia. The disorder is probably due to a focal dystonia of the laryngeal musculature, and this would be consistent with the type of neurological disorders that were associated with it in our cases. Symptomatic benefit follows the therapeutic division of one of the recurrent laryngeal nerves, in selected cases.


Neuropsychological syndrome in a patient with episodic howling and violent motor behaviour.

A patient with atypical temporal lobe seizures involving violent behavior was found to exhibit the neuropsychological syndrome described by Luria (1966, 1976) as pathognomonic of lesions in the depths of the left temporal lobe. This syndrome, mainly an audioverbal memory defect with relatively intact phonemic hearing, was evident in spite of an intact intellect.


Diagnosis of subdural haematoma by computed axial tomography: use of xenon inhalation for contrast enhancement.

A subdural haematoma is described in which a definite computed tomographic (CT) scan diagnosis was made only after contrast enhancement had been achieved by the inhalation of xenon. The different types of enhancement obtained with iodide containing contrast media and with xenon are discussed. The use of xenon to obtain further information in conditions which are inadequately elucidated by conventional CT must be balanced against its anaesthetic effects and relatively high cost.


Sectorial optic atrophy and homonymous, horizontal sectoranopia: a lateral choroidal artery syndrome?

Two patients with sectorial optic atrophy and homonymous, horizontal sectoranopia are described. Neuroradiological investigations localised the visual pathway lesion to the lateral geniculate body. The peculiar nature of the field defect and the optic atrophy appeared explicable in terms of ischaemia in the territory of the lateral choroidal artery.


Hemiplegia and the billowing mitral leaflet syndrome.

Four young patients presenting with major neurological episodes and with coexisting prolapsing mitral valve are described. An attempt at correlating the two entities is made. The neurological complications of prolapsing mitral valve are stressed.


The effect of progesterone on the spontaneous interictal spike evoked by the application of penicillin to the cat's cerebral cortex.

The effect of intravenous infusion of progesterone and Mebumal (ACO, Sweden; penotobarbital, INN) on the frequency and amplitude of the spontaneous interictal spikes from a penicillin focus in the cerebral cortex was investigated in ovariectomized cats anaesthetized with chloralose. The plasma concentration of progesterone was determined. It was found that the generation of penicillin spikes was depressed by progesterone in plasma concentrations as low as 40 ng/ml. Equimolar doses of Mebumal were less effective.


Neuronal ceroid-lipofuscinosis. Studies of granulocyte enzyme activities.

Neuronal ceroid-lipofuscinosis is characterized by pigmentary degeneration of the retina, psychomotor degeneration, epilepsy and intracellular deposition of ceroidlipofuscin. Recent reports have suggested that deficiency of peroxidase is the basic genetic defect. However, deficiency of myeloperoxidase could be demonstrated in some but not all patients; this deficiency was noted only when p-phenylenediamine (PPD) was used as hydrogen donor and could not be confirmed with guaiacol. We found that horseradish peroxidase (HR-P) oxidized PPD in the absence of added H2O2. The oxidative product of PPD showed the same absorption spectrum as the peroxidative product. The oxidation of PPD by HR-P was not inhibited by catalase or superoxide dismutase. In addition, catalase oxidized PPD in the presence of H2O2. Soluble and granular fractions obtained from human polymorphonuclear leukocytes (PMN) also oxidized PPD in the absence of H2O2. Addition of H2O2 inhibited the oxidation of PPD in some cell fractions. This inhibition could be partially eliminated by dialysis of the cell fractions. Thus, PPD is not a suitable hydrogen donor for the study of peroxidase. This may explain the variable results obtained by the previous investigators. In contrast, guaiacol did not show these undesirable characteristics. The PMN peroxidase (measured with guaiacol), catalase, beta-glucuronidase, acid and alkaline phosphatases were studied in individuals from three families with juvenile neuronal ceroid-lipofuscinosis. Family 1: an affected boy and healthy parents; all showed normal enzyme activities in both soluble and granular fractions. Family 2: two affected sisters, one healthy sib and mother, and Family 3: one affected boy; all showed reduced peroxidase activities in the granular fractions. Other enzymes were normal. The role of peroxidase deficiency in the pathogenesis of neuronal ceroid-lipofuscinosis is not clear. The basic defect of this syndrome remains uncertain.


Familial communicating syringomyelia.

Calssical cervical syringomyelia was found in 3 members of one family. All 3 underwent air myelogram, and a Chiari malformation type I and postural collapse of the spinal cord was found in each case. An affected 7-year-old boy was discovered after a clinical and radiological survey of 8 first-degree relatives on the basis of mild scoliosis, pyramidal tract signs in the lower limbs and enlarged sagittal diameter of the cervical canal. One other member had basilar impression of the skull but no neurological abnormalities. No positive correlation was found between either the size of the cystic cord enlargement or descent of the ectopic tonsils with the duration or severity of the neurological findings. Suboccipital decompressive craniotomy and upper cervical laminectomy in one case was followed by improvement in strength and sensation 1 year later. Progression in familial syringomyelia appears to occur through a mechanism identical to that in the sporadic form and surgery is therefore also indicated. In affected families, routine survey of close relatives for abnormal neurological signs, and radiological evidence of scoliotic deformity of the spine, enlarged cervical canal and bone abnormalities at the craniovertebral junction may prove valuable for early detection. A dominantly inherited, genetically determined malformation seems to be the probable mechanism of inheritance in this family.


The stability of the auditory evoked potentials in normal man and patients with multiple sclerosis.

Sequential records of the early and middle components of the auditory evoked potential in response to a click stimulus have been obtained over a period of 2.5 years in normal subjects and in patients with multiple sclerosis. The latencies of all the components were highly consistent in the control subjects and in the patients who were clinically stable throughout the period of study. In constrast, in some of the patients who had clinical relapses during the study there was variation in the latency and amplitude of some of the components. The significance of this variation is discussed and the poor correlation between the sites of the new lesions as determined clinically and the auditory evoked potential variability is emphasised.


Motor innervation of the striated oesophagus muscle. Part 1. Intramural distribution of the right and left vagus nerve in the rat oesophagus as revealed by the glycogen depletion technique.

The muscularis propria of the rat oesophagus is entirely made up of striated muscle fibres. All fibres are of the same histochemical type, which is characterized by high activity of actomyosin ATPase, medium activity of oxidative enzymes and relatively strong reaction for phosphorylase. Prolonged stimulation (10 Hz, 30 min) of the vagus nerves causes depletion of the glycogen content of the oesophageal muscle fibres. This stimulation effect can be visualized by means of the PAS technique as well as by the histochemical reaction for phosphorylase. In 8 animals the right and in 8 animals the left vagus nerve were stimulated repetitively and the stimulated muscle fibres were identified in transverse sections of the oesophagi, stained for phosphorylase. The muscle fibres supplied by one vagus nerve are distributed all over the circumference of the oesophagus. In the upper third of the oesophagus stimulation of either vagus nerve depletes slightly less than 50% of the muscle fibres, whereas in the lower two-thirds the right vagus nerve seems to predominate to a certain degree. In 3 animals both vagus nerves were stimulated simultaneously. Bilateral stimulation produced a very extensive depletion. Only a few muscle fibres remained unaffected. Functional implications of the results, the question of polyneuronal innervation and the role of the myenteric plexus are discussed.


Pattern-reversal visual evoked potential. Method of analysis and results in multiple sclerosis.

A detailed method of analysis of the pattern-reversal visual evoked potential is presented. This method takes into account a number of parameters in addition to the latency of the major surface-positive component (P2) and has been tested in a group of 50 normal subjects and in 98 patients with established or suspected multiple sclerosis (MS). It was found that this more detailed form of analysis improved the detection rate of abnormal responses in the MS subjects particularly in those classified in the suspected category. The potential value of this form of analysis, particularly in clinical neurophysiology laboratories where the recording of visual evoked potentials is the only technique employed in the investigation of patients with suspected MS, is discussed.


Motor innervation of striated oesophageal muscle. Part 2. Characteristics of the oesophagomotor fibres in the rat studied by implanting the vagus nerve into a skeletal muscle.

In 12 rats the right vagus nerve distal to its recurrent laryngeal branch was implanted into the inferior segment of the denervated sternohyoid muscle. One month after implantation the first signs of neuromuscular transmission at the vagal motor endings could be recorded. Two months after implantation the reinnervated muscles showed vigorous contractions on electrical stimulation of the vagus nerve. During the performance of propulsive waves of the oesophagus the implanted vagus nerve caused clonic to tetanic contractions of the sternohyoid muscle, thus proving the oesophagomotor genesis of the reinnervating nerve fibres. In addition, the vagus-innervated motor end-plates were shown to exhibit the same ultrastructural peculiarities as the original neuromuscular junctions of the oesophagus. In sections stained for cholinesterase it could be demonstrated that the oesophagomotor fibres had preferentially reinnervated the denervated motor end-plates. In many instances the subneural apparatus was not completely covered by the vagal axon terminals. Newly formed, ectopic vagal motor endings were few in number and confined to muscle fibres immediately adjacent to the site of nerve-implantation. Six months after implantation some of the vagal motor endings showed signs of degeneration. As in the oesophagus, the reinnervating oesophagomotor fibres proved to be unmyelinated, sometimes forming a plexus-like intramuscular network before terminating at motor end-plates. Myelinated vagal nerve fibres were also observed running between the skeletal muscle fibres, but they did not establish any demonstrable form of neuromuscular contacts. It was concluded that, in the rat, the myelinated fibres of the oesophageal nerves are afferent, whereas the oesophagomotor fibres, although supplying striated muscle, are unmyelinated.


Lipid abnormalities in hereditary neuropathy. Part 2. Serum phospholipids.

The mean percentage of linoleate to total fatty acids in phosphatidylcholine and lysophosphatidylcholine fractions of serum phospholipids from neuropathic patients with HMN (hereditary motor neuropathy, also called distal type of progressive muscular atrophy), HMSN-I and HMSN-II (two types of peroneal muscular atrophy), and FA (Friedreich's ataxia) was reduced by approximately 10--20% (P less than 0.001). On the other hand, the mean percentage of nervonic acid in sphingomyelin was elevated by 9--20%. No significant difference was observed in phosphatidylethanolamine between neuropathic patients and control subjects. The mean concentration of phosphatidylcholine and sphingomyelin was also significantly reduced in neuropathic patients (except in HMN and HMSN-III). A significant correlation between endogenous 2-linoleoyl-sn-glycerol-3-phosphocholine and cholesteryl linoleate synthesis in vitro suggests that the decreased activity of phosphatidylcholine acyltransferase (EC 2.3.1.43; LCAT) in neuropathic patients is influenced by the fatty acid composition of their lipoprotein substrate. Furthermore, the reduction of phosphatidylcholine and of cholesteryl linoleate synthesis in vitro in neuropathic patients was affected by age and sex. It is unlikely that the reduced linoleate level in serum phosphatidylcholine for most, possibly all, of the inherited neuropathies studied here reflects a specific biochemical disorder. Possibly it reflects a more generalized biochemical alteration common to inherited neuropathy. One possibility is that biosynthesis of new membrane in axonal regeneration, segmental remyelination and Schwann cell hyperplasia may reduce the serum linoleate pool.


Multivesicular bodies in cortical dendrites of two patients with Alzheimer's disease.

Biopsy fragments from the frontal cortex of 2 patients with Alzheimer's disease were studied with ultrastructural and cytochemical methods. A great number of light and dark, acid phosphatase positive, multivesicular bodies were observed in dendrites and their spines, in all cortical layers, being more abundant in layers 3 and 4. A close topographic relationship between these organelles and post-synaptic membranes was found. It is postulated that these findings might be related to the neurite formation of the senile plaques and to the synaptic involvement in Alzheimer's disease.


Early-juvenile Batten's disease--a recognisable sub-group distinct from other forms of Batten's disease. Analysis of 5 patients.

In most cases where rectal biopsy is performed to diagnose Batten's disease, there is good correlation between biopsy appearance, age of onset, clinical course and electrophysiological parameters. As a result 3 forms of the disease have been recognised; infantile, late infantile and juvenile. In a review of rectal biopsy in Batten's disease at the Hospital for Sick Children, Great Ormond Street, we have studied the few cases in which no such correlation appeared to exist. In 5 the features are sufficiently similar to suggest a further recognisable sub-group which could be descriptively called "early juvenile". The clinical course, electrophysiological features and the absence of vacuolated lymphocytes in this subgroup are as found in the late infantile form, whereas the biopsy findings are identical to those of the juvenile form. By analogy with some of the mucopolysaccharidoses we speculate that the genes of the late infantile and juvenile forms of Batten's disease are allelic and that the "early juvenile" sub-group is a genetic compound presenting as an intermediate phenotype.


An association between mitochondria and microtubules in synaptosomes and axon terminals of cerebral cortex.

A substantial number of synaptosomes prepared from rat cerebral cortex were found by electron microscopy to contain a horseshoe-shaped mitochondrion flanked by an arc of three to ten microtubules opposite the synaptic membrane specializations. The microtubules were replaced by characteristic paracrystals following the incubation of synaptosomes with vinblastine sulfate. A similar spatial organization of microtubules and mitochondria was also observed in some axon terminals of the cerebral cortex in situ. The significance of this novel observation is discussed with regard to the role of microtubules in axonal transport at the synaptic terminal and previous reports on the identification of tubulin in synaptosomes and subsynaptic structures.


Intracellular localization of acetylcholinesterase in nerve terminals and capillaries of the rat superior cervical ganglion.

The ultrastructural localization of acetylcholinesterase (AChE) has been studied in the superior cervical ganglion of the rat. Previous descriptions of the general pattern of localization were confirmed, but in addition, AChE reaction product was found within vesicles in preganglionic nerve terminals, and in pinocytotic vesicles and along the basement lamina of capillaries. There was indication of a continuity between AChE reaction product in the cisternae of the rough endoplasmic reticulum of the principal ganglion cells and extracellular reaction product. These observations are discussed with particular reference to AChE as a secretory protein.


The larval electric organ of the weakly electric fish Pollimyrus (Marcusenius) isidori (Mormyridae, Teleostei).

The larval electric organ of Pollimyrus isidori consists of four longitudinal tubes, a dorsal and a ventral pair, which begin behind the skull, end at the beginning of the caudal peduncle and show myotomic segmentation. The elementary units are, apparently, transformed muscle fibres called electrocytes. They are shorter and thicker than muscle fibres, with long stalks and are found in the medial part of the deep lateral muscle. Electron microscopy reveals a clear difference between the anterior and posterior face of the electrocyte. Anteriorly, deep linear invaginations of the surface membrane together with many small vesicles of about 100 nm diameter can be seen. Posteriorly, many plasma membrane invaginations and vacuoles are found together with numerous cytoplasmic organelles--pleiomorphic nuclei, Golgi apparatus, oblong mitochondria and multivesicular bodies. The stalk originates at the posterior face and the nerve terminals are situated at the distal end of the stalk. In the electrocyte, myofibrils, similar to those found in muscle fibres, can be detected with clearly visible Z lines but with only a suggestion of H zones. Two bundles of myofibrils can be seen arranged orthogonally in the electrocyte. Strong acetylcholinesterase activity was found on the anterior face and on the innervated stalk. Under the given recording conditions the overall discharge amplitude of the larval electric organ reaches a maximum of about 100 mV peak to peak. The pulse duration is 1 millisecond and the main phase is head-positive.


Schwann cell myelin ensheathing C.N.S. axons in the nerve fibre layer of the cat retina.

In the retina of the cat the axons of the nerve fibre layer are unmyelinated and are provided with a C.N.S. myelin sheath only in the extraocular part of the optic nerve. The present study demonstrates that in the apparently normal cat retina close to the optic disc, some axons of the nerve fibre layer run for a short distance in the perivascular space of the retinal arteries. While coursing in the perivascular space, these C.N.S. axons become transiently myelinated by Schwann cells, which form a typical P.N.S. myelin sheath. These P.N.S. myelin sheaths terminate at a heminode in the transitional zone in which the C.N.S. axons penetrate the perivascular glial sheath in order to leave or to re-enter the nerve fibre layer. It is suggested that the Schwann cells, which elaborate the P.N.S. myelin around C.N.S. axons, are descendants of the Schwann cells of the perivascular autonomic nerves. The present study shows that Schwann cells are able to provide previously unmyelinated C.N.S. axons with a P.N.S. myelin sheath.


Nerve cell degeneration and death in the trigeminal ganglion of the adult rat following peripheral nerve transection.

Trigeminal ganglia of normal rats and of adult rats subjected to unilateral transection of the infraorbital nerve were studied by light and electron microscopy. Counts of ganglion cells in ganglia on operated and unoperated sides were made following long postoperative survival times. The ultrastructural changes in ganglia of the operated side were studied from 3 to 70 days postoperatively. The quantitative observations show that a considerable loss of ganglion cells takes place on the operated side. The ultrastructural observations demonstrate the occurrence of ganglion cell degeneration, nerve fibre degeneration and phagocytosis by satellite and Schwann cells. The results are compatible with the view that degeneration of trigeminal afferents in the brain stem following lesions of peripheral trigeminal nerve branches is related to retrograde degeneration of trigeminal ganglion cells.


Cat hindlimb tactile dermatomes determined with single-unit recordings.

1. Single-unit recording from dorsal root ganglia was used to determine the dermatomes of L4-S2 segments in the cat. Dermatomes for low-threshold myelinated mechanoreceptor afferents are smaller than those reported in earlier studies of whole-root dermatomes. There are also sufficient discrepancies among earlier studies and with the present data to merit reexamination of hindlimb whole-root dermatomes. 2. Receptive-field size varies directly with distance from toes. Length/width ratio is essentially constant for different parts of the hindlimb. 3. Estimates of innervation density verify the long-standing assumption that innervation density is greater for foot and toes than for proximal hindlimb, at least for low-threshold cutaneous myelinated afferents.


Cytoarchitecture and thalamic connectivity of third somatosensory area of cat cerebral cortex.

1. The third somatosensory area (SIII) was identified in the cat cerebral cortex by the recording of surface potentials evoked by deflection of a single contralateral mystacial vibrissa. A small amount of tritiated leucine was then injected at the center of the focus of evoked activity and, after a suitable survival period, the brain was prepared for autoradiography. 2. As defined by the presence of an autoradiographic injection, the SIII focus lay in a cytoarchitectonic field characterized in particular by the presence of very large pyramidal cells in layer V and corresponding to area 5a of Hassler and Muhs-Clement (24). 3. The terminal ramifications of corticothalamic cells, as outlined by axoplasmically transported label, formed clustered aggregations in the medial division of the posterior group of thalamic nuclei (Pom) and not in the ventrobasal complex (VB). This part of Pom is known to receive fibers from the spinal cord. 4. Injections of horseradish peroxidase primarily affecting area 5a retrogradely labeled cells in Pom but not in VB. 5. Injections of isotope in the two other foci of vibrissa-evoked activity usually recorded in each brain were invariably found to label a part of area 3b of the first somatosensory area (SI) in the case of the more anterior focus. The second focus sometimes lay in area 2 of SI and sometimes in the second somatosensory area (SII).


Indirect, across-the-midline retinotectal projections and representation of ipsilateral visual field in superior colliculus of the cat.

1. In agreement with previous work, we have found that the ipsilateral visual field is represented in an extensive rostral portion--from one-third to one-half--of the superior colliculus (SC) of the cat. This representation is binocular. The SC representation of the ipsilateral visual field can be mediated both directly, by crossed retinotectal connections originating from temporal hemiretina, and indirectly, by across-the-midline connections relaying visual information from one-half of the brain to contralateral SC. 2. In order to study the indirect, across-the-midline visual input to the SC, we have recorded responses of SC neurons to visual stimuli presented to either the ipsilateral or the contralateral eye of cats with a midsagittal splitting of the optic chiasm. Units driven by the ipsilateral eye, presumably through the direct retinotectal input and/or corticotectal connections from ipsilateral visual cortex, were found throughout the SC, except at its caudal pole, which normally receives fibers from the extreme periphery of the contralateral nasal hemiretina. Units driven by the contralateral eye, undoubtedly through an indirect across-the-midline connection, were found only in the anterior portion of the SC, in which is normally represented the ipsilateral visual field. Receptive fields in both ipsilateral and contralateral eye had properties typical of SC receptive fields in cats with intact optic pathways. 3. All units having a receptive field in the contralateral eye had also a receptive field in the ipsilateral eye; for each of these units, the receptive fields in both eyes invariably abutted the vertical meridian of the visual field. The receptive field in one eye had about the same elevation relative to the horizontal meridian and the same vertical extension as the receptive field in the other eye; the two receptive fields of each binocular unit matched each other at the vertical meridian and formed a combined receptive field straddling the vertical midline of the horopter...


An intracellular analysis of some intrinsic factors controlling neural output from inferior mesenteric ganglion of guinea pigs.

1. In vitro studies were conducted on neurons within the inferior mesenteric ganglion (IMG) of guinea pigs to investigate how intrinsic features of the spike-generating process interact with preganglionic inputs to produce the output firing patterns of these neurons. Intracellular-electrode techniques were used to monitor and control electrical activity of IMG neurons. Preganglionic inputs were activated either synchronously by stimulating an attached nerve trunk or asynchronously by leaving the ganglion attached to a segment of terminal colon and activating the colonic-IMG mechanosensory system. 2. Ninety-seven percent of the neurons studied demonstrated an afterspike hyperpolarization (ASH). The ASH process was activated only by the occurrence of a spike and did not have a synaptically induced component. Further activation of this process was produced by two or more spikes having interspike intervals less than the duration of an ASH following a single spike. An aftertrain hyperpolarization (ATH) resulted from this progressive activation. The amplitude of both the ASH and the ATH decreased when the resting membrane potential was hyperpolarized by current injection or by increasing the external potassium ion concentration. 3. Neuronal excitability was reduced during the ASH. From this observation it was concluded that when IMG neurons operate in the occasional-firing mode, the ASH process prevents output frequency from greatly exceeding the reciprocal of the ASH duration produced by a single spike. 4. Two types of synaptically induced slow depolarizations were observed: a slow, long-latency depolarization and a short-latency depolarization (SLD). These depolarizations differed in their latency, onset, and duration. Both were capable of converting synchronous, preganglionic input from subthreshold (non-spike-activating) to threshold (spike-activating) activity. 5. Neurons having resting potentials more positive than -60 mV were capable of firing in the rhythmic-firing mode; 40% of these neurons demonstrated tonic- and 60% phasic-firing behavior. Frequency-current relations for tonic-discharging neurons were linear from the rhythmic-firing threshold to current levels approximately 2.5 times the threshold value. Minimal frequency for tonic firing and the slope of the linear portion of the frequency-current relation were indirectly related to the duration of the ASH. 6. This study suggests that sympathetic, noradrenergic neurons of the IMG can operate in either the occasional- or rhythmic-firing mode. In the physiologic state in vivo, most IMG neurons probably do not produce action potentials in excess of 10-15 Hz because of their intrinsic properties which regulate firing in both modes of operation.


Receptive-field properties of neurons in binocular and monocular segments of striate cortex in cats raised with binocular lid suture.

1. We studied the receptive fields of 171 striate cortical neurons from 17 cats raised with binocular lid suture. Of these, 102 fields were within 10 degrees of the area centralis and the remaining 69 were at least 38 degrees from the vertical meridian. 2. Based on their different response properties, cells were divided into three broad groups: the mappable cells (49%) had clearly defined receptive fields, the unmappable cells (31%) were activated by visual stimuli but had diffuse fields which could not be hand plotted, and the visually inexcitable cells (20%) could not be activated by visual stimuli. Very few (less than or equal to 12% of the total sample) normal simple or complex cells could be found. 3. Orientation selectivity was assessed in these cells. Only 12% displayed orientation selectivity within normal bounds, and these were all mappable cells. None of the unmappable cells had discernible orientation selectivity. 4. Ocular dominance was assessed for 62 of the centrally located receptive fields. Among mappable cells, there was an abnormally low proportion of binocular fields, while no such abnormality was seen for unmappable cells. 5. For 47 of the neurons, average response histograms were compiled for moving stimuli of various parameters in an effort to evoke the maximum discharge or peak response. This peak response was normal for mappable cells but reduced for unmappable cells. 6. We devised a technique for studying potential inhibitory receptive-field zones in these neurons, validated the method in normal striate cortex, and used it to test 20 mappable cells in the lid-sutured cats. None showed the pattern of strong inhibitory side bands seen in normal simple cells, although six showed weak or abnormal inhibitory zones. Interestingly, six of the seven visually inexcitable cells tested by this method had purely inhibitory receptive fields. 7. The effects of binocular suture were essentially identical for the binocular and monocular segments since the cell types and their response properties did not differ between these two areas of cortex. Furthermore, the cortical monocular segments of these cats seemed qualitatively different from the deprived cortical monocular segment after monocular suture. This extends an analogous difference for these cats reported for the monocular segments of the lateral geniculate nucleus. We thus conclude that monocularly and binocularly sutured cats develop by qualitatively different mechanisms. For the former, competition between central synapses related to each eye is a prominent feature of geniculocortical development, whereas, for the latter, such specific forms of geniculocortical development may not obtain.


Properties of auditory nerve responses in absence of outer hair cells.

1. Recordings were made from chinchilla auditory nerve fibers after portions of the cochlear outer hair cell (OHC) population were destroyed with the antibiotic kanamycin. In most cases the inner hair cell (IHC) population was completely preserved as determined by phase-contrast microscopy. We presume that the remaining IHCs are functionally normal, and thus that recordings obtained from fibers originating from the lesioned cochlear segment reflect IHC behavior. 2. Behavioral thresholds were measured for all animals both before and after the production of the cochlear lesion. The audiograms and the histological evaluation of the ears were the basis for assessing whether a particular fiber originated in a normal, pathological (shifted threshold; IHC only), or border region. These criteria also identified the animals that sustained IHC damage together with the destruction of part of the OHC population. Only the data obtained from those fibers which probably originated from the OHC-free segment of the cochlea are considered in detail. 3. Fibers whose characteristic frequency (CF) identified them as belonging to the normal (audiometrically and histologically) region, were found to be normal in all respects. 4. Fibers from the border region (where the audiogram has a steep slope between normal and hearing-loss regions probably corresponding to the segment where OHC loss progresses from less than 10% to more than 90%) had very complex response patterns. Their frequency threshold curves (FTC) showed great variability. In general, the closer the fiber was to the fully developed lesion, the more abnormal its FTC became. 5. Those units that were concluded to have originated from the OHC-free part of the cochlea could be divided into three categories on the basis of the shape of their FTCs. A small fraction had very broad tuning (9%). The majority (53%) had approximately normal tail segment, normal bandwidth of the tip segment, and highly elevated threshold at CF. A group of fibers (38%) could not be assigned a CF. Probably the FTC of most of these latter fibers are similar to those of the previous group, but the sharply tuned short tip segment was either missed or was not reachable on account of its extremely high threshold level. 6. Such indexes of fiber response as latency, spontaneous rate, and time pattern (PST histograms) were not affected by the loss of OHCs. 7. On the basis of the data and of the assumptions made it was suggested that outer hair cells provide a frequency-dependent sensitizing influence to the inner hair cells. The frequency dependence could best be expressed as a flat-topped band pass characteristic.