[Functional differentiation of different portions of the the rat neocortex]

The effect of uni- and bilateral ablation of rostral and caudal parts of neocortex on conditioned avoidance reflex was studied on naive and pretrained albino rats. Maximal impairment of the reflex was seen after bilateral ablation of the caudal region of neocortex, minimal one--after unilateral neocortex ablation. The rats without rostral cortex showed medium impairment. After extirpation of caudal cortex the number of positive reactions to light was greater in pretrained rats than in naive ones. After total cortical extirpation the previously elaborated conditioned reflex disappeared irreversibly. The conclusion is made on functional heterogeneity of the rostral and caudal cortex.