Infusions of ascorbic acid into the medial preoptic area facilitate appetitive sexual behavior in the female rat.
Ascorbic acid (AA), also known as Vitamin C, enhances dopamine (DA) transmission in mesolimbic and nigrostriatal terminals and augments DA-mediated behaviors. It is not yet known whether AA has a similar influence in other DA terminals, in particular terminals of the incertohypothalamic system that modulate the function of the medial preoptic area (mPOA). In female rats, DA in the mPOA plays a critical role in the generation of appetitive sexual responses, notably solicitations, hops, and darts, and we have shown previously that the role of DA in this region on female sexual behavior changes depending on the hormonal profile of the female. Since AA has often been used as a vehicle control in the examination of rat sexual behavior, the present study examined the effect of infusions of AA to the mPOA of sexual experienced ovariectomized rats under two hormonal conditions: partially-primed with estradiol benzoate (EB) alone or fully-primed with EB and progesterone. Relative to saline baselines, females under both hormonal conditions displayed a significant increase in appetitive sexual behaviors following infusions of AA. No difference in lordosis behavior was observed following AA infusions relative to saline baselines. We suggest that the mechanism by which AA infusions to the mPOA increase appetitive sexual behaviors in female rats may be through dose-dependent DA receptor interactions, possibly through both presynaptic release mechanisms and postsynaptic DA D1-related messenger systems.
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, QC H4B 1R6, Canada.
M Dean
MD
Graham
James G
JG
Pfaus
D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects* / Q000502:physiology; D001205:Ascorbic Acid / Q000494:pharmacology*; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D011301:Preoptic Area / Q000187:drug effects* / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology; D051381:Rats; D020318:Rats, Long-Evans; D012726:Sexual Behavior, Animal / Q000187:drug effects* / Q000502:physiology
C074283:estradiol 3-benzoate; D011374:Progesterone; D004958:Estradiol; D001205:Ascorbic Acid
Appetitive behaviors; Ascorbic acid; Female sexual behavior; Medial preoptic area; Steroid hormones