Cholinergic regulation of female sexual behavior in rats demonstrated by manipulation of endogenous acetylcholine.

Infusions of the cholinesterase inhibitor, eserine, into the lateral ventricle of the brain facilitated lordosis in ovariectomized, estrogen primed female rats. Lordosis was also facilitated by infusions of 5 or 10 micrograms acetylcholine when this was accompanied by a low dose of eserine. Systemic treatment with the muscarinic antagonist, atropine (2 mg), completely blocked the facilitative effects of eserine and acetylcholine. In female rats made highly receptive by treatment with estrogen and progesterone, lordosis was inhibited by infusion of scopolamine into the lateral ventricles. These results agree with previous findings that sexual receptivity is regulated in part by endogenous cholinergic activity.