THE AMYGDALA AND THE CONTROL OF GONADOTROPHIN SECRETION

Abstract

ABSTRACT In adult male rats, the oxygen consumption of the amygdala is increased following castration and decreased following hypophysectomy. When both operations are performed in the same animal, the metabolic activity of the amygdala is as low as that found following hypophysectomy only. The stimulating effect of castration on amygdalar oxygen consumption can be reversed by administering in vivo, to castrated animals, adequate amounts of testosterone, though testosterone is completely ineffective if added in vitro to the incubation media containing amygdalar tissue taken from castrated animals. In vivo treatment of castrated hypophysectomized animals with LH and FSH increases the metabolic activity of the amygdala; moreover, the in vitro addition of FSH or of LH to amygdalar slices taken from normal animals is capable of increasing the oxygen consumption of this structure to levels similar to those found in the amygdala of castrated animals. None of the experimental manipulations used proved capable of modifying the oxygen consumption of the hippocampus or of the cerebral cortex.