Invited Symposium: Neural Substrates of Sexual Motivation and Performance as Revealed by Neural Immediate-Early Gene Expression
Previous studies characterized the neural circuitry controlling sexual behavior initiation in the male Syrian hamster (Mesocricetus auratus), but mechanisms responsible for cessation of mating remain unclear. A multiple-mating paradigm was utilized along with Fos-immunocytochemistry and behavioral analysis of brain lesions to reveal structures regulating sexual satiety. When mated for 4 consecutive days, males cease after 9.0±0.7 ejaculations on day 1, but stop after 2.7±0.6 ejaculations every subsequent day. Comparing Fos-immunoreactivity (Fos-ir) within brains of animals stopped after 1 ejaculation on either day 1 (far from satiety) or day 4 (near satiety) revealed elevated Fos-ir within subregions of the bed nucleus of the stria terminalis and medial amygdala (Me) on day 4. Specifically, two 3clusters2 of Fos-ir nuclei were only observed within the Me of males near satiety. Experiment 2 examined whether Me damage would alter mating duration. Animals mated before and after bilateral Me lesions. Postoperatively, the percent ejaculating and number of ejaculations increased only in males with damage to a region of Me previously reported to contain the Fos-ir 3clusters2. These results are interpreted to reveal a discrete limbic region coordinating sexual satiety. Completion of these studies occurred in collaboration with Drs. S.W. Newman, R.I. Wood, and L.M. Coolen.
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|Parfitt, DB; (1998). Neural Substrates Modulating Sexual Satiety: Evidence Convergence via Fos and Lesion Analysis. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Invited Symposium. Available at URL http://www.mcmaster.ca/inabis98/baum/parfitt0347/index.html|
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