Grant: Discovery Grants Program - Individual

The objectives of the research proposed in this application are to continue our identification of specific neuroanatomical and neurochemical systems that underlie appetitive and consummatory aspects of sexual behavior in female and male rats. A combination of neuropharmacological and molecular techniques will be used to examine the role of monoamines (dopamine and serotonin), small molecules (glutamate and GABA), and neuropeptides (opioids, melanocortins, oxytocin) within mesolimbic and hypothalamic brain regions in response to different types of sexual stimulation. These stimuli will include pheromonal cues and genitosensory stimulation. In vivo microdialysis will be used to characterize dopamine, glutamate, GABA (or different neuropeptides) in mesolimbic and hypothalamic regions during sexual interactions. The research will focus on the mechanisms that control sexual arousal, desire, reward, inhibition, and disinhibition, and will focus on solicitation and pacing behaviors in female rats, and sexual anticipation and chasing behaviors in male rats, in addition to traditional consummatory measures of lordosis and mounting behavior. The development and maintenance of appetitive sexual behaviors appear to require the activation of sexual reward systems following ejaculation in male rats or paced vaginocervical stimulation in female rats. Our previous work has indicated an interaction between the medial preoptic area and ventromedial nucleus of the hypothalamus, the ventral tegmental area of the midbrain, and several amygdala nuclei in generation of sexual reward expectancies. In addition to studies of appetitive sexual behavior, the neural systems that underlie sexual inhibition will begin to be elucidated by pairing sexually active rats with nonreceptive partners, by examining the mechanisms of sexual refractoriness or estrus termination, and by examining the effects of sexual nonreward during an animal's first sexual experiences. This work will provide new insights into the neural control of appetitive and consummatory sexual behaviors in rats, behaviors that can be viewed as models of human sexual arousal, desire, and copulatory performance.