Post-stress analgesia after lesions to the central nucleus of the amygdala in rats

Abstract

In two experiments the role of the central nucleus of the amygdala under two modes of loot-shock analgesia was studied in 39 male Moll-Wistar rats. In Experiment I a 4 min continuous foot-shock, dependent on neural mechanism was used as a stressor. Analgesia was produced by regularly intermitted 20 min of foot-shock action in Experiment II which evoke an opioid, humorally mediated mechanism. The results suggested that the central nucleus is involved only in the humoral regulation of the opioid form of analgesia. This finding fits well with the concept of limbic control of the anterior pituitary and the pituitary-adrenocortical axis, and points to the role of the amygdaloid complex in processing of stressful stimuli.