[An EEG analysis of the structural interrelationships of the thalamofrontal system in the recovery of conditioned-reflex behavior in amygdalectomized rats].

Unilateral damage of the baso-lateral amygdala in white non-strain rats led to decrease of the number of instrumental responses and increase of their latencies in the course of the first two weeks after the surgery. This period was characterized by increase of the delta- and theta-frequency bands in electrograms of the orbito-frontal cortex and dorsomedial nucleus of the thalamus. During the next two weeks this increase was observed only in the orbito-frontal cortex. Functional reorganization of interconnections between the limbic and thalamo-cortical brain structures is supposed to underly phenomena observed.