Inhibition of Ovulation in the Rat by Electrical Stimulation of the Lateral Amygdala

Abstract

Effects of electrical stimulation of the lateral amygdaloid areas on ovulatory gonadotropin release were examined in adult Wistar female rats. Electrical stimulation was applied in rats in proestrus under ether aneshtesia with square wave pulses of 0.5ms duration and 100Hz frequency for 30min (30 sec on and off).
Stimulation of the lateral amygdala blocked ovulation in 50% of animals when it was applied between 13: 30 and 14: 30 with a current of 300 μA. Stimulation of the medial amygdala under the same experimental condition was absolutely ineffective to block ovulation. Sham stimulation was also ineffective. In determining the gonadotropin concentration in serum, the stimulation into the lateral amygdala was observed to inhibit the ovulatory release of LH, FSH and prolactin.
It may be said that the lateral amygdaloid area participates in the control of gonadotropin rerease in an inhibitory manner.