Scopolamine inhibition of female sexual behavior in rhesus monkeys (Macaca mulatta).
Previous research supports the activational role of central cholinergic mechanisms in rodent female sexual behavior. This experiment examined if similar central cholinergic mechanisms facilitate female rhesus monkey (Macaca mulatta) sexual behavior. Eight ovariectomized female rhesus monkeys received daily estradiol benzoate priming (5 microg/kg, SC). After 13-16 days of estrogen priming, animals were injected intravenously with either the cholinergic antagonist, scopolamine (0.70 mg/kg), or saline vehicle (1 ml/kg). Results indicate that the female proceptive behaviors of noncontact presentations significantly decreased 1545 min after scopolamine injection. Scopolamine inhibition was sustained up to 75 min only after 15 days of estrogen priming. Scopolamine did not significantly reduce other female sexual behaviors. Additionally, significant decreases in the number of mounts and intromissions, but not hip touches, were displayed by males exposed to scopolamine-treated females. This research suggests the possibility of a central cholinergic mechanism regulating female sexual behavior in rhesus monkeys. However, the general nature and duration of the cholinergic regulation of primate female sexual behavior differs substantially when compared to rodent behavior.
Lynch
C S
CS
Department of Psychology, University of Southwestern Louisiana, Lafayette 70504-3131, USA.
Ruppel
T E
TE
Domingue
R N
RN
Ponthier
G L
GL
D000818:Animals; D003864:Depression, Chemical; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D008253:Macaca mulatta; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D010052:Ovariectomy; D011187:Posture; D012601:Scopolamine / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D018727:Muscarinic Antagonists; D004958:Estradiol; D012601:Scopolamine