001, rank-sum test) In the following, we will present gamma-band

001, rank-sum test). In the following, we will present gamma-band activity by analyzing signals at 45 Hz because this activity displayed the strongest spatially selective persistent memory activity across the population of recordings (see below). At 45 Hz, we found that LFP power was not significantly selective for either RT (SRT: p = 0.32, RRT: p = 0.67, rank-sum

test). We obtained similar results at other frequencies above 30 Hz (For example, at 65 Hz, SRT: p = 0.11, RRT: p = 0.23, rank-sum test). Since greater beta-band LFP power is associated with slower RTs, decreasing beta-band LFP power Selleck 3-Methyladenine may speed movement initiation. The RT selectivity of beta-band LFP power before a reach and saccade is spatially specific and present before movements to the preferred direction. Before movements to the null direction, the activity was not significantly greater during slow trials regardless of whether activity was sorted by saccade RT or reach RT (Figures 4C and 4D; RRT: p = 0.43. SRT: p = Ibrutinib nmr 0.27, rank-sum test). To further establish the specificity of beta-band activity for specific interactions between reach and saccade processes, we asked whether RT

selectivity is also present when saccades are made alone. There was no significant difference between activity across the population for the fast versus slow RTs when saccades were made alone in the preferred direction (Figure 4E; at 15 Hz, p = 0.18, rank-sum test) or the null direction (Figure 4F; at 15 Hz, p = 0.63, rank-sum test). Lack of RT selectivity SB-3CT before saccades is also not associated with a lack of spatial selectivity. LFP activity was significantly greater for saccades in the preferred direction than in the null direction (Figures 4E and 4F; Supplemental Information). Therefore, beta-band LFP power in area LIP correlates with SRT only when a saccade is made with a coordinated reach in the preferred direction. The level of beta-band power before movements to the preferred direction, however, is greater before saccades made alone than before coordinated movements. Since SRTs are faster before coordinated reach and

saccade movements than before saccades made alone, this is consistent with increasing beta-band activity slowing down movement initiation. The overall picture is that beta-band activity exerts a braking mechanism to control the timing of saccades with reaches. Next, we determined whether beta-band selectivity for RT was also present in the spiking activity of area LIP neurons. We recorded isolated action potentials from 59 neurons that showed spatially tuned activity before a coordinated reach and saccade (p < 0.05; permutation test, 48 neurons in Monkey H; 11 neurons in Monkey J). To determine whether spiking activity that is coherent with beta-band LFP activity also predicts RT, we first divided neurons into two groups: coherent cells and not coherent cells.

, 1998 and Tofaris et al , 2002) but also many others not previou

, 1998 and Tofaris et al., 2002) but also many others not previously reported in injured nerves—such as IL11, Scye1 and Cxcl10 (Table 1). Interestingly, a number PR-171 concentration of other factors likely to be important in the regenerative response, such as MEGF10—an engulfment receptor implicated in the phagocytosis of myelin debris (MacDonald et al., 2006), neuronal growth factors such as GDNF, and blood vessel growth factors (VEGFA and C) were also strongly upregulated. Importantly, the upregulation of many, but not all, of these genes in vivo was confirmed by

qRT-PCR analysis (Figure 6B). Moreover, analysis of CM from NSRafER cells using a rat cytokine antibody array showed that the cytokines on the array, which were upregulated in the microarray analysis (MCP-1, VEGF, and TIMP-1), were also found at increased levels in the CM, confirming that the increase in mRNA is accompanied by a corresponding increase in cytokine production (Figure S6B). The majority of the cytokines on the antibody array, however, were not upregulated in the microarray analysis and we could not detect increased levels of these cytokines in the CM indicating a specificity of the response. The one exception was PDGF-AA, which was not upregulated in the microarray analysis but was found at slightly higher levels in the CM and

in vivo. It will be of great interest to explore the role of these candidates in the regenerative process. The PNS is a privileged environment maintained by the BNB. Breakdown of the BNB is thought to be required for the robust inflammatory response Dactolisib that occurs following nerve injury (Weerasuriya, 1988). To test the effects of activation of the ERK signaling pathway in Schwann cells on the BNB, we injected WT or P0-RafTR secondly mice with Evans blue, a tracer that passes from blood vessels into the endoneurium and perineurium following breakdown of the BNB. In WT animals, the dye was restricted from the inner spaces of the sciatic nerve (Figure 6C). In contrast, in P0-RafTR animals, breakdown of the BNB

was observed as early as day 4, with complete breakdown by day 5, coincident with the increased numbers of inflammatory cells found within the nerve (Figure 5 and Figure 6C). These results indicate that breakdown of the BNB can be triggered by Raf-activated signals from Schwann cells independent of trauma. These findings show that that the activation of the ERK-signaling pathway in myelinating Schwann cells is sufficient to drive both demyelination and the inflammatory response with important implications for pathologies such as inflammatory neuropathies. To test the requirement of this pathway following injury, we used the highly-selective MEK1/2 inhibitor PD0325901 (Solit et al., 2006) to block the increase in ERK signaling seen in Schwann cells following nerve injury compared to the vehicle-treated controls.

We found that MRCs were retained in all three mutant genotypes (

We found that MRCs were retained in all three mutant genotypes ( Figure 5A; Table 1), indicating that neither TRPV protein is required for the generation of MRCs. Additionally, loss of one or both of these ASH-expressed TRPV channels had no detectable effect on the size, latency, or time course of MRCs ( Table 1). Furthermore, though TRPV null

CHIR99021 mutations shifted the MRC current-voltage relationship toward 0 mV, MRCs reversed above +40 mV. Thus, the major component of MRCs in TRPV mutants remains a Na+-permeable channel, indicating that neither TRPV channel is a major contributor to MRCs in ASH ( Figures 5B and 5C). Next, we determined how the loss of ocr-2 and osm-9 affected the minor deg-1-independent MRC and found that MRCs in osm-9ocr-2;deg-1 triple mutants were the same size and had the same kinetics as deg-1 single mutants ( Figure 5A; Table 1). The triple mutant also had the same reversal potential as deg-1 mutants ( Figure 5B). Collectively, these data establish that neither the major or minor components of mechanotransduction S3I-201 cell line current in ASH require

OSM-9 or OCR-2. Force depolarized ASH neurons as expected for changes in membrane potential activated by inward currents (Figure 5D). The MRP time course reflected that of the underlying MRC. No action potential-like events were detected either in response to force or current injection (Figure S2). Thus, like other sensory neurons in C. elegans ( Goodman et al., 1998, O’Hagan et al., 2005 and Ramot Florfenicol et al., 2008), the ASH neurons appear to signal without using classical action potentials. MRPs evoked by saturating mechanical stimuli were similar in wild-type and osm-9ocr-2 double-mutant ASH neurons ( Figure 5D; Table 2), reaching average maxima of −39 ± 3 mV

(mean ± SEM, n = 10) and −35 ± 2 mV (mean ± SEM, n = 5), respectively ( Table 2). Such MRPs are likely to open voltage-gated calcium channels, since depolarization above −50 mV is sufficient to activate calcium currents in other C. elegans sensory neurons ( Goodman et al., 1998). Force evoked only tiny depolarizations in deg-1 ASH neurons that never rose above −50 mV ( Figure 5D; Table 2), suggesting that voltage-gated calcium channels are not activated in ASH neurons lacking DEG-1. In all genotypes studied, MRP amplitude mirrored MRC size ( Figure 5D). These results demonstrate that OSM-9 and OCR-2 are not required for the generation of either MRPs or MRCs and establish that DEG-1, by contrast, is essential for the generation of both MRPs and MRCs. The eponymous deg-1 was the first DEG/ENaC gene to be identified in any organism ( Chalfie and Wolinsky, 1990). Here, we show that it encodes the third DEG/ENaC protein known to be a pore-forming subunit of a sensory MeT channel. Several lines of evidence support this conclusion. First, external loads open amiloride-sensitive, sodium-permeable ion channels in ASH.

SHCs were identified by their abneural location and by their ecce

SHCs were identified by their abneural location and by their eccentrically placed hair bundle ( Hirokawa, 1978; Figure 1A). The distance of the recording site from the apical end of the papilla was measured and normalized by the total length of the papilla (∼3.6 mm) and is expressed as d, the fractional distance from the apex;

in most experiments, d = 0.35–0.45. Hair cell recordings were made with borosilicate patch electrodes filled (except for the nonlinear capacitance measurements; see below) with an intracellular solution containing (in mM): 137 KCl, 0.5 BAPTA, 3 MgATP, 10 Tris creatine phosphate, 10 HEPES (pH 7.2) (295 mOsm/l); patch electrodes were connected to an Axopatch 200B amplifier (Molecular Devices); the residual series resistances was 7.5 ± 3.4 MΩ (n = 40). Membrane potentials were corrected for junction potentials and current selleck products flow through the residual series resistance. Unless otherwise noted, the holding potential was −84 mV. Hair bundles were mechanically stimulated by a fluid jet (Kros et al., 1992) from a pipette, tip diameter ∼10 μm, driven by a 25 mm diameter piezoelectric disc (MuRata Electronics) or occasionally a stiff glass probe driven by a piezoelectric stack actuator (PA8/12, Piezosystems Jena). In some experiments, hair bundles were deflected with glass fibers more compliant than the hair bundle driven with

a piezoactuator. Flexible fibers, ∼100 μm long and 0.5 to 1 μm in diameter www.selleckchem.com/products/MS-275.html with stiffness ∼1 mN/m, were constructed and calibrated (Ricci et al., 2000) and the tip was placed against the shortest edge of the bundle; hair bundle heights others were 6.5–5.5 μm at the location studied (d = 0.35–0.45). The driving voltage to the piezoactuator was filtered at 2 kHz. Bundle motion was determined by projecting an image of the tip of the hair bundle or the end of the flexible fiber near the bundle onto a pair of photodiodes (LD 2-5; Centronics) at 270× magnification and recording changes in photocurrent, filtered at 2 kHz. Freestanding hair bundles were imaged

at their tip where they appeared as a bright line; when flexible fiber stimulation was used, the fiber was placed between a third and a halfway down from the top of the bundle; if too close to the top, it was prone to slip over the bundle during stimulation. The differential photocurrent, proportional to the displacement of the object, was calibrated by measuring its amplitude and polarity when displacing the photodiodes a known distance in the image plane, then using the magnification to determine the equivalent motion in the object plane. In one set of experiments, the tectorial membrane was not removed and remained attached to the hair bundles. In these experiments, the hair cells were stimulated en masse by extracellular currents applied with a stimulus isolation unit (A395; World Precision Instruments) connected to agar-filled glass electrodes contacting chloridized silver wires placed on either side of the papilla.

To examine functional expression and in vivo function of TRPM3 in

To examine functional expression and in vivo function of TRPM3 in the somatosensory system, we made use of a functionally uncharacterized TRPM3-deficient mouse strain (Figure S2). Western blot analysis demonstrated TRPM3 protein expression in DRG and TG tissue from Trpm3+/+ but not from Trpm3−/− mice selleck compound ( Figure 1C). Trpm3−/− mice were viable, fertile, and exhibited no obvious differences from Trpm3+/+ controls in terms of general appearance, gross anatomy, body weight (at 10 weeks: 24.9 ± 0.9 g in Trpm3+/+ and 27.0 ± 0.9 g in Trpm3−/− mice [n = 15 for each group; p = 0.29]), core body temperature (37.89°C ± 0.1°C in Trpm3+/+ and 38.06°C ± 0.2°C in Trpm3−/− mice [n =

6 for each group; p = 0.45]), heart rate (629 ± 25 bpm in Trpm3+/+ and 585 ± 29 bpm in Trpm3−/− mice [n = 6; p = 0.28]) and basal blood glucose levels (135 ± 4 mg/dl

in Trpm3+/+ and 135 ± 4 mg/dl in Trpm3−/− mice [n = 7; p = 0.96]). Previous work revealed that the mouse TRPM3α2 isoform is rapidly and reversibly activated by low micromolar concentrations of the neurosteroid PS, and that PS is not acting on several other TRP channels expressed in DRG or TG neurons, including TRPV1, TRPV2, TRPA1, or TRPM8 (Figure 4A and data not shown; see also Chen and Wu, 2004 and Wagner et al., 2008). We therefore used PS to test for functional TRPM3 expression in freshly isolated DRG and TG neurons. PS evoked robust and reversible calcium signals in 58% of DRG (n = 303) (Figure 2A) and 57% of TG neurons (n = 273) isolated RG7204 cell line from Trpm3+/+ mice ( Figures 2A, 2C, 2D, and S3). PS responses, like capsaicin responses ( Caterina et al., 2000 and Davis et al., 2000), were restricted to small-diameter cells (diameter <25 μm; Figure 3), known to include unmyelinated nociceptors neurons. Importantly, the fraction of PS-sensitive neurons was drastically decreased in DRG and TG preparations Bumetanide from Trpm3−/− mice ( Figures 2B–2D and S3),

whereas the fractions that responded to the TRPA1 agonist MO or the TRPV1-agonist capsaicin were not changed ( Figures 2C and 2D). Conversely, responses to PS were conserved in DRG and TG neurons obtained from Trpv1−/−, Trpa1−/− and combined Trpv1−/−/Trpa1−/− mice ( Figures S4A–S4E). In some experiments, we also stimulated sensory neurons with nifedipine (10 μM), a drug that has been described as an agonist of both TRPA1 (EC50 = 0.4 μM; Fajardo et al., 2008) and TRPM3 (EC50 = 30 μM; Wagner et al., 2008). We found that the fraction of nifedipine-sensitive neurons was not significantly altered in DRG and TG preparations from Trpm3−/− mice, in line with previous work suggesting that TRPA1 is the main determinant of nifedipine-induced Ca2+ responses in sensory neurons ( Fajardo et al., 2008).

In four SHCs, depolarizing voltage steps to membrane potentials

In four SHCs, depolarizing voltage steps to membrane potentials

of +10 to +30 mV produced 31 ± 12 nm of movement when working against a flexible fiber of stiffness 1.2 mN/m; the force generated was 37 ± 14 pN. The largest force observed was 55 pN. Second, the force-displacement relationship yielded a stiffness value for the hair bundle. The relationship was usually close to linear but in a few cases there was evidence of the nonlinearity described previously (Howard and Hudspeth, 1988). The stiffness for small displacements (measured under hair cell voltage clamp) showed substantial variation from cell to cell ranging from 1.6 mN/ m up to 25 mN/m with a mean of 8.6 ± 8.9 mN/m (n = 7; d = 0.35–0.43). The variation probably reflects different sites of

attachment of the fiber from the bundle tip, the apparent stiffness being the square of the distance from the bottom of the bundle ( Crawford click here and Fettiplace, 1985). The exact attachment point was difficult to measure accurately but the tip of the fiber was usually placed behind the shortest row of stereocilia or on the rake and was thus attached between a third and halfway down the bundle NU7441 cost from the top, in which case the stiffness is increased between 2.3-fold and 4-fold. Assuming an average of these two values, the expected stiffness for forces applied at the tip are approximately one-third of those measured; i.e., ∼3 mN/m. Measurements were also made on THC bundles for which a stiffness measurement of 4.4 ± 1.2 mN/m (n = 6) was obtained; if the same correction is applied for fiber placement the stiffness is reduced to 1.5 mN/m. These stiffness values are larger than those reported for isolated chicken hair cells (0.5 mN/m; Szymko et al., 1992) and for turtle hair bundles (0.6–1.2 mN/m; Crawford and Fettiplace, 1985; Ricci et al., 2000). Chicken hair bundle at the location assayed have twice the number of stereocilia (∼110; Tilney and Saunders, 1983) compared to turtle hair cells,

which should make them stiffer. The hair bundles of SHCs in vivo are constrained by tight connections to a tectorial membrane. An important question about force generation by hair bundles is whether it is functionally significant when operating against the mass and stiffness of the tectorial membrane. To address the question, we used an isolated basilar papilla in Megestrol Acetate which the tectorial membrane was left in place and we electrically stimulated the hair cells en masse by passing extracellular currents across the papilla (see Experimental Procedures; Bozovic and Hudspeth, 2003). In these experiments, the tectorial membrane was more than 10 μm thick (mean = 10.9 ± 2.9 μm, n = 5), and evidence that it remained intact included that it was still attached to the supporting cells abneural of the SHCs and that its transverse fibers (Figure 7A, middle image) were undisturbed and ran close to the tops of the hair bundles.

, 1991, Sharp et al , 1996, Skaggs et al , 1995, Touretzky and Re

, 1991, Sharp et al., 1996, Skaggs et al., 1995, Touretzky and Redish, 1996 and Zhang, 1996) and the activity bump is moved in accordance

with changes in the animal’s head orientation (Figure 3A). The dynamics of space-modulated cells can be modeled on a two-dimensional neural sheet where cells are arranged according to the location of their firing fields and the activity bump is moved in accordance with the animal’s direction and speed of movement (Samsonovich and McNaughton, 1997 and Zhang, 1996). The two-dimensional model was originally proposed as a mechanism for spatial representation find more by place cells, but, like the oscillatory-interference model of O’Keefe and Recce (1993), the model implicitly predicted periodic firing fields. With the discovery of grid cells, this model could also be translated to entorhinal networks. One of the earliest attractor models of grid cells used a self-organized pattern of activity that, if displaced across medial entorhinal Ion Channel Ligand Library solubility dmso neurons in concordance with the movements of the rat, imprinted a grid map to each of its neurons (Fuhs and Touretzky, 2006). Multiple “bumps” of activity emerged as a consequence of concentric ripples of positive and negative

connections. To support translocation of the activity, each cell was assigned a preferred head direction. The bumps of activity were then displaced based on both velocity input to units with the appropriate head direction preference and asymmetric inhibition enforcing a single direction of movement (Fuhs and Touretzky, 2006). Navigation over small timescales resulted in the successful generation of grid cell patterns; however,

population activity was constructed using biologically unrealistic piecewise trajectories. Spiking activity was plotted for a small sampled portion of the environment, and the network activity was then reset before the next sample. This resulted in the grid pattern falling apart when realistic trajectories over longer periods of time were used (for more detail, see Burak and Fiete, 2006). Another concern was that the initial connectivity used in the Fuhs and Touretzky model led to overwhelming excitation near the borders of the environment, causing neurons to fire over the entire environmental boundary. Disruption of path integration then occurred as avoiding of these edge effects required significant attenuation of the recurrent activity near the borders, which caused distortions and rotations in the population pattern. Edge effects in attractor networks can be avoided by supposing that neurons at the edges of the network connect with neurons on the opposite edges, resulting in periodic boundaries (Figure 3B). Periodic boundaries effectively turn the network into a torus shape of connectivity and naturally cause the firing fields of neurons on the attractor map to repeat at regular intervals (McNaughton et al., 1996 and Samsonovich and McNaughton, 1997) (Figure 3B).

, 1997, Tachezy et al , 2002 and Lun et al , 2005) There are few

, 1997, Tachezy et al., 2002 and Lun et al., 2005). There are few reports concerning the morphological

this website aspects of T. mobilensis ( Culberson et al., 1986). Therefore, a more detailed study is needed, mainly at an ultrastructural level. Thus, the purpose of the present work was to provide a more detailed study of T. mobilensis comparing it with T. foetus. In addition, the endocytic activity and cytotoxicity of T. mobilensis was compared with the behavior of T. foetus. T. mobilensis strains USA:M776 and 4190 were purchased from ATTC (Rockville, MD, USA). The T. foetus K strain was isolated by Dr. H. Guida (Embrapa; Rio de Janeiro, Brazil) from the urogenital tract of a bull, and this strain has been maintained in culture since the 1970s. The T. foetus CC09-1, a fresh isolate, was obtained from Dr. C.M. Campero (Patología Veterinaria, Instituto Nacional de Tecnología Agropecuaria, Balcarce, Buenos Aires, Argentina) and axenized as previously described ( Pereira-Neves et al., 2011). All cultures

were cultivated in Trypticase/yeast extract/maltose (TYM) medium ( Diamond, 1957) supplemented with 10% fetal Idelalisib calf serum. The cells were grown for 24–36 h at 37 °C, which corresponds to the logarithmic growth phase. The human colonic adenocarcinoma cell line, Caco-2, was purchased from ATCC (Rockville, MD; ATCC HTB 37). The cells were cultured in 25 cm2 flasks with DMEM (Dulbecco’s modified Eagle’s medium, Sigma, USA) supplemented with 10% fetal calf serum and incubated at 37 °C with 5% CO2. Caco-2 epithelium cells were allowed to grow until a confluent monolayer culture was achieved. Caco-2 cells were cultured in 24-well plates at a density of 105 cells/ml for 24 h. Monolayers of Caco-2 cells were co-incubated with T. mobilensis or T. foetus in a cell ratio of 10:1 (trichomonads: Caco-2 cells) for different periods of time at 37 °C in 5% CO2. For control experiments, parasites were not added to the monolayers. For the viability assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT; 0.5 mg/ml in DMEM) was added to each well and incubated for an additional hour at 37 °C. The medium was discarded, and

1 ml of an acid isopropanol solution (4 M HCl:isopropanol PA; 1:99, v/v) was added to each well to solubilize out the colored formazan product that was formed. Absorbance was read at 590 nm, and the background was subtracted at 630 nm on a scanning ELISA microplate reader (ELX800). The viability was calculated with the following equation: 1 − (E/C). All measurements of experimental (E) samples (A590–630) were indexed to those of control (C) samples (E/C), which showed no loss of viability, and then subtracted from 1.0. All data points were performed in triplicate. The results are the average of three experiments. Statistical significance was evaluated by a 2-way ANOVA. In all cases, a P-value <0.05 was considered significant. Uncovered latex beads were used to analyse the binding capability of T.

Scan protocols are given in the Supplemental Experimental Procedu

Scan protocols are given in the Supplemental Experimental Procedures. Experimental procedures are given in the Supplemental Experimental Procedures. [11C]Methyl iodide was produced and transferred into 300 μl of dimethyl sulphoxide (DMSO) containing 1.5–2 mg of tert-butyldimethylsilyl desmethyl precursor and 10 mg of potassium hydroxide at room temperature. The reaction mixture was heated to 125°C and maintained for 5 min. After cooling the reaction vessel, 5 mg of tetra-n-butylammonium fluoride hydrate in 600 μl of water was added to the mixture to this website delete the protecting group, and then 500 μl of HPLC solvent was added to the reaction vessel. The radioactive mixture was transferred into

a reservoir for HPLC purification (CAPCELL PAK C18 column, 10 × 250 mm; acetonitrile/50 mM ammonium formate = 4/6, 6 ml/min). The fraction corresponding to [11C]PBB3 was collected in a flask containing 100 μl of 25% ascorbic acid solution and 75 μl of Tween 80 in 300 μl of ethanol and was evaporated to dryness under a vacuum. The residue was dissolved in 10 ml of saline (pH 7.4) to obtain [11C]PBB3 (970–1,990 GBq at the end of synthesis [EOS]) as an injectable solution. The final formulated product was radiochemically pure (≥95%) as detected by analytic HPLC (CAPCELL PAK C18 column, 4.6 × 250 mm; click here acetonitrile/50 mM ammonium formate = 4/6,

2 ml/min). The specific activity of [11C]PBB3 at EOS was 37–121 GBq/μmol, and [11C]PBB3 maintained its radioactive purity exceeding 90% over 3 hr after formulation. Experimental procedures are given as Supplemental Experimental Procedures. Radiolabeling of PIB was performed MRIP as described elsewhere (Maeda et al., 2011).

The specific activity of [11C]PIB at EOS was 50–110 GBq/μmol. Experimental procedures are given in the Supplemental Experimental Procedures. PET scans were performed using a microPET Focus 220 animal scanner (Siemens Medical Solutions) immediately after intravenous injection of [11C]PBB2 (28.3 ± 10.3 MBq), [11C]PBB3 (29.7 ± 9.3 MBq), or [11C]mPBB5 (32.8 ± 5.9 MBq). Detailed procedures are provided in the Supplemental Experimental Procedures. Three cognitively normal control subjects (64, 72, and 75 years of age; mean age, 70.3 years) and three AD patients (64, 75 and 77 years of age; mean age, 72 years) were recruited to the present work (Figure 8). Additional information on these subjects is given in the Supplemental Experimental Procedures. The current clinical study was approved by the Ethics and Radiation Safety Committees of the National Institute of Radiological Sciences. Written informed consent was obtained from the subjects or their family members. PET assays were conducted with a Siemens ECAT EXACT HR+ scanner (CTI PET Systems). Detailed PET scan protocols are provided in the Supplemental Experimental Procedures.

These stimuli were below nociceptive thresholds, as determined by

These stimuli were below nociceptive thresholds, as determined by vocalizations. Sural nerve stimulation did not produce short-latency responses in tibialis anterior (TA) in either control or mutant mice. However, a short-latency reflex was present in gastrocnemius (Gs) in 8 of 11 control mice, as compared to only two of eight dI3OFF mice (chi-square test, p < 0.05), despite the use of multiple shocks in potentiating

the response (Figure 6Ii). The mean-normalized EMG response was 1.8 ± 1.4 (mean ± pooled SD) in dI3OFF mice (n = 8) in comparison to 4.1 ± 3.5 in control GSK1210151A littermates (n = 11, p < 0.05; Figure 6Iii). This loss or reduction of motor response to sural nerve stimulation in dI3OFF mice indicates that dI3 INs

mediate a short-latency, low-threshold cutaneous-motor reflex (Figure 6J). To assess how silencing Selleck NVP-AUY922 the output of the dI3 INs affects motor tasks that require cutaneous afferent feedback, we tested the performance of mutants with a locomotor task. On a horizontal ladder with uniform spacing between rungs, the number of hindlimb missteps was greater in dI3OFF mice (control, 2.8 ± 3.0 slips per 100 steps; dI3OFF, 9.2 ± 5.7 slips per 100 steps; p < 0.05; Figure 7A). In addition, falls from the ladder were occasionally observed during the testing of dI3OFF mice but never with control littermates. This suggests that hindlimbs rely on dI3 INs to ensure appropriate grip of the ladder rungs during ladder walking. To explore the functional consequence of eliminating dI3 IN output further, we turned to a paw grip task that involved low-threshold cutaneous receptors (Witney et al., 2004). Both control and dI3OFF adult mice attempted to grasp the metal bars (indicating that they could sense the bars), but the volar surfaces (forelimb and hindlimb) of the paws of dI3OFF mice did not fully grip the bars (Figure 7B). During

slow inversion of the cage top, the dI3OFF mice would slide down the grid because of PAK6 an apparent failure to maintain adequate grip strength (Movie S1). The angle at which the dI3OFF mice were unable to remain on the cage top was 58° ± 12° from the horizontal axis (mean ± pooled SD; n = 3 trials for three mice; Figure 7C). When the grid was inverted to angles beyond vertical, dI3OFF mice were unable to hang onto the grid (n = 10 out of ten, three trials each; seven males, three females; P30–P120; Figure 7D and Movie S1). Control littermates could hang on for long periods averaging 50 s per trial (n = 12 out of 12, three trials each; four males, eight females; P30–P120; Figure 7D and Movie S2). These data suggest that the silencing of the output of dI3 INs impairs grasping and the ability to regulate grip strength in the face of an increasing load.