The ventrolateral hypothalamus in guinea pigs is an area of the brain which contains a high concentration of receptors for estradiol and progesterone. This area is also critical for the induction of female sexual receptivity by estradiol and progesterone. The first experiment presented in this dissertation demonstrated that over 35% of the neurons in the ventrolateral hypothalamus which have estrogen-induced progestin receptors also contain the neuropeptide substance P. The ventrolateral hypothalamus was the primary place in the forebrain where progestin receptors and substance P occurred in the same cells. Thus, the ventrolateral hypothalamus may be an important site in the regulation of substance P by steroid hormones. The second experiment determined the efferent projections from the steroid-sensitive, ventrolateral hypothalamus. Anterograde tract tracing labeled fibers throughout the preoptic area, medial hypothalamus, amygdala, and the dorsal midbrain. The final experiment examined specific efferent projections of ventrolateral hypothalamic neurons which contained progestin receptors and substance P by combining retrograde tract tracing with fluorescent immunocytochemistry. Most of the neurons containing both substance P and progestin receptors projected to the dorsal midbrain. Fewer of these neurons projected to the bed nucleus of the stria terminalis, preoptic area, or medial amygdala. Some of these pathways may be involved in female sexual behavior, as well as other functions which are mediated by steroid hormones and substance P.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-8682 |
| Date | 01 January 1993 |
| Creators | Ricciardi, A. Kirsten H. Nielsen |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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