Potentiation of lordosis behavior by intrahypothalamic infusion of synthetic luteinizing hormone-releasing hormone.

Saline and luteinizing hormone-releasing hormone (LRH) were infused into the medial preoptic area (MPOA), arcuate nucleus (ARC), lateral hypothalamic area (LHA) and the cerebral cortex (CC), and the effects on sexual behavior were studied in estrone- (E-) primed ovariectomized (OVX) female rats. Each cannulated, OVX female known to be sexually active was primed with E in doses too low to initiate consistent mating behavior. LRH infusion in either the MPOA or ARC faciliated sexual behavior as measured by the lordosis-to-mount (L/M) ratio; LRH infusion in the LHA or CC, as well as saline infusion in all neural sites, was ineffective in initiating comparable behavior patterns. The results concur with findings utilizing systemic LRH injections and support the notion that LRH may act directly on neural tissue to potentiate lordosis behavior in the female rat.