Neuron activity of the ventromedial hypothalamus and the medial preoptic area of the female monkey during sexual behavior

Abstract

To elucidate the neural mechanisms of the sexual behavior of the female monkey, single neuron activity of the ventromedial hypothalamus (VMH) and the medial preoptic area (MPOA) was recorded during sexual behavior with a male partner. Copulation was initiated when either the male's touch elicited passive presenting ('receptive presenting') or when the female's active presenting ('proceptive presenting') evoked mounting from the male. Proceptive presenting with no mating acts evoked activity changes in about 40% of cells in the VMH (mainly excitation) and MPOA (mainly inhibition). When the male's mating acts were manifested, 56% of VMH cells and 87% of MPOA cells showed firing changes during presenting, with the proportion of MPOA cells which showed excitation significantly increased. Progress of mating acts of the male partner (e.g. increases in the rate and/or number of thrusting), enhanced activity changes in about 40% of VMH and 70% of MPOA cells tested. The findings suggest that VMH and MPOA cells are involved in the control of sexual behavior in different ways: excitation of the VMH and inhibition of MPOA are related to execution of presenting, while excitation of MPOA is related to sexual intercourse with a male partner; and mating acts of a male partner modulate activity of both VMH and MPOA neurons of the female.