a central visual stimulus generated by a red led. after the cats had reached at least 80% accuracy in identifying the location of the sound stimulus, each was implanted with one or two bilateral pairs of cryoloops over the different sections of the auditory cortex; 10 sections were defined. cryoloops were turned on so that the loops reached a temperature of 3°c (plus or minus 1°c), first unilaterally, then bilaterally, next unilaterally on the other side, and finally baseline task performance was recorded after recovering from cooling. this cycle was repeated several times for each cat. of the 10 sections that were deactivated, only deactivation of 3 sections, the ai (primary auditory cortex)/dz (dorsal zone), paf (posterior auditory field), and aes (anterior ectosylvian sulcus) sections, were found to have an effect on sound localization. at baseline, cats were able to locate 90% of the sound stimuli. unilateral deactivation of any one of these sections resulted in a contralateral impairment in sound localization, or 10% accuracy. bilateral deactivation of any combination of these three sections resulted in a 180° deficit to 10% of sound locations identified, although this accuracy implied that cats were still able to orient to the hemifield where the sound occurred above chance (7.7%). since the primary auditory cortex and dorsal zone were concurrently cooled, the investigators performed another study in which the ai and dz were examined as separate entities to further establish the sections of auditory cortex contributing to sound localization. the experimental design was the same as the above-mentioned design with the exception that only the ai and dz sections were implanted with separate cryoloops. again, it was found that unilateral simultaneous cooling deactivation of the ai and dz generated contralateral sound localization deficits while bilateral deactivation created a deficit in both hemifields (10% sound location identification). bilateral deactivation of ai alone resulted in only 45% accuracy within 30° of the target. bilateral deactivation of dz resulted in 60% accuracy but with larger errors, often into the hemifield opposite the target. therefore, az deactivation produces a higher number of small errors while deactivation of dz leads to larger but fewer errors. this finding that ai and dz deactivation produce partial deficits in sound localization implies that the previous finding that paf and aes deactivation have more considerable contributions to sound localization than either the ai or dz. visual cortex studies in cats, the ability to disengage visual attention and redirect it to a new location is normally localizable to posterior middle suprasylvian (pms) cortex, and investigators wanted to determine if, when primary visual cortical areas 17 and 18 are removed at birth, the neural functions of these areas are redistributed across other sections of the visual cortex, such as the pms. this neural compensation would spare the function of areas 17 and 18 but at a possible cost of reducing the functional capabilities of the compensating cortex. after birth, areas 17 and 18 were lesioned in four cats, and they were then trained on behavioral tasks requiring detection and orienting to a visual or sound (as a negative control) stimulus. then bilaterial cryoloops were implanted over the pms and ventral posterior suprasylvian (vps) cortices. the vps lies adjacent to the pms, and these areas were previously surmised to receive networks from other visual areas. investigators found that, for moving visual stimuli, unilateral deactivation of pms cortex partially impaired task performance when visual stimuli were moved into the hemifield opposite the side of the brain being cooled. additionally deactivating the ipsilateral vps cortex produced more complete task impairment. bilateral deactivation of the pms cortex, either alone or in combination with bilateral vps deactivation, largely reversed the unilaterally cooling-induced impairments. for static visual stimuli, unilateral deactivation of pms fully impaired task performance in the contralateral hemifield, while bilateral deactivation created full neglect of stimuli across the entire field of vision. for the vps, unilateral deactivation had no effect on task performance, while bilateral deactivation generated inconsistencies in performance. all impairments were completely reversed when cooling was terminated. this study showed that the plasticity of neural tissue enabled functions from removed brain sections to redistribute to functionally distinct sections of cortex. reversible cooling was performed on slices of rat visual cortex, and spike characteristics were observed. cooling depolarized the neural tissue, bringing the cells closer to the threshold necessary for an action potential (spike). cooling increased spike width, and between 12 and 20°c, spike amplitudes were greatest. cooling decreased passive potassium conductance while increasing the activation threshold and lowering the amplitude of voltage-gated potassium channels (thus essentially reducing the cells’ capability to repolarize after an action potential). no sodium channel characteristics were altered. hence, basic membrane properties were changed due to the modified conductance ratio of potassium and sodium, and this change was temperature dependent. somatosensory cortex studies part of the somatosensory cortex of rats is arranged in distinct sections called barrels that account for stimuli sensed by each whisker. cooling the somatosensory cortex surface helps to dissociate the activity generated in different barrels, thus bringing to light some of the dynamics involved in cortical processing of sensory inputs. other cryotips were used in male rats to cool the caudate putamen (cp) to study consumption behaviors. the shaft of the cryotips were not insulated, so overlying tissue including meninges and cortex overlying the cp were also cooled. all three regions were subsequently cooled in combinations and separately to determine which areas contribute to consumption reduction. cooling the cortex alone created a conditioned consumption reduction; consumption reduction was contingent on pairing a sucrose solution (to be consumed) with cortical cooling.