Do amygdaloid nucleus centralis and nucleus lateralis serve similar functions in defensive responding in cats?

ABSTRACT

Bar pressing escape response has been trained, extinguished, retrained and then transformed into avoidance response in cats subjected to electrocoagulation of either the dorsolateral part of the central nucleus (Group CE) ox the lateral nucleus (Group L) of amygdala. In comparison with normal carts Group L was deficient in acquisition of the short latency escape responses and Group CE was handicapped in reacquisition of the escape response after the extinction procedure. Both lesioned groups were unable to acquire avoidance responding. Group CE was marked by gradual decrease of the sensitivity to shock in the course of learning, whereas Group L was less sensitive to changes in experimental procedures than the other two groups. However, most of the observed group differences were related to a decrease of sensitivity to shock and to a lowered general emotionality produced by lesions in both amygdaloid nuclei.