An intact medial preoptic area is necessary for zaprinast to modulate paced mating behavior in female rats

The present study examined the interaction between the regulation of paced mating behavior by the medial preoptic area (mPOA) and by the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway, as modulated by zaprinast, a phosphodiesterase inhibitor. Rats receiving mPOA or sham lesions were tested for paced mating behavior. Subsequently, rats were treated with zaprinast (3 mg/kg) before a second paced mating test. The expected lengthening of contact-return latencies following intromissions and ejaculations was observed in rats with mPOA lesions relative to rats with sham lesions. In addition, rats with sham lesions responded to zaprinast with a lengthening of contact-return latency following ejaculation. Contact-return latencies did not change in response to zaprinast in rats with mPOA lesions. These results demonstrate that the alterations in paced mating behavior observed in rats with mPOA lesions persist despite manipulation of the nitric oxide-cyclic guanosine monophospate pathway.

► Contact-return latencies are lengthened in rats with mPOA lesions. ► Activity in the mPOA and PDE-5 inhibitors, like zaprinast, appear to modulate genital blood flow. ► Alterations in paced mating behavior observed in rats with mPOA lesions are not affected by zaprinast administration.