The goal of this research is to understand how gonadal steroids act on the brain to modify mammalian social behaviors. It is pursued by focusing on how testosterone (T) activates social behaviors in adult males and affects sexual differentiation. In each case, parallel analyses examine the effects of T on sexually dimorphic cell groups in the preoptic area (POA) of the hypothalamus and on masculine behaviors involved in reproduction and communication. The research will capitalize on the fact that the sexually dimorphic area (SDA) of the gerbil POA has been implicated in the hormonal control of male sexual behavior and scent marking, a form of olfactory communication. The SDA is a set of hormone- accumulating cell groups that responds to T morphologically and histochemically in adulthood. At least one subdivision of the SDA, the SDA pars compacta (SDApc) also sexually differentiates under the control of T during early development. While structural sex differences have been identified in the POA of at least nine species, including humans, evidence linking the SDA to hormonal control of masculine social behaviors is stronger than in any other species. Thus it is the best model available for attempting to identify cellular markers of T action and the neural pathways involved in these behaviors. During the period of requested support, this model will be developed further by (1) determining if cell-body lesions of the SDA disrupt mating and marking as electrolytic lesions do, and if the deficits are related to damage to specific subdivisions; (2) determining if it is easier to elicit marking or mating with hormone implants in the SDA than in adjacent areas, and if the effects vary for different subdivisions; (3) studying the distribution of muscarinic receptors in the SDA and their relationship to the facilitation of scent marking by muscarinic antagonists; (4) determining which afferents and efferents are important for mating or marking and if any mediated the effects of T on the SDA; (5) determining if SDA cells directly link the pertinent afferents; (6) determining if the pertinent input, output or intervening SDA cells accumulate T or its metabolites; (7) attempting to identify the transmitters/modulators of the behaviorally important pathways; (8) studying the effects of pudental nerve cuts on the SDApc; and (9) continuing research on sexual differentiation of the SDA and SDApc. Processes affecting the development and expression of sexual and communication behaviors clearly affect mental health.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37MH026481-20
Application #
2244166
Study Section
Special Emphasis Panel (NSS)
Project Start
1977-08-01
Project End
1996-11-30
Budget Start
1995-01-01
Budget End
1995-11-30
Support Year
20
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
Yahr, Pauline (2015) Two aromatase inhibitors inhibit the ability of a third to promote mating in male rats. Horm Behav 75:41-4
Yahr, Pauline (2011) Sex difference and response to testosterone in gabaergic cells of the medial preoptic nucleus and ventral bed nuclei of the stria terminalis in gerbils. Horm Behav 59:473-6
Simmons, D A; Hoffman, N W; Yahr, P (2011) A forebrain-retrorubral pathway involved in male sex behavior is GABAergic and activated with mating in gerbils. Neuroscience 175:162-8
Finn, Patricia D; Yahr, Pauline (2005) Projection from the ventral bed nucleus of the stria terminalis to the retrorubral field in rats and the effects of cells in these areas on mating in male rats versus gerbils. Horm Behav 47:123-38
Simmons, Danielle A; Yahr, Pauline (2003) GABA and glutamate in mating-activated cells in the preoptic area and medial amygdala of male gerbils. J Comp Neurol 459:290-300
Simmons, Danielle A; Yahr, Pauline (2002) Projections of the posterodorsal preoptic nucleus and the lateral part of the posterodorsal medial amygdala in male gerbils, with emphasis on cells activated with ejaculation. J Comp Neurol 444:75-94
Heeb, M M; Yahr, P (2001) Anatomical and functional connections among cell groups in the gerbil brain that are activated with ejaculation. J Comp Neurol 439:248-58
Heeb, M M; Yahr, P (2000) Cell-body lesions of the posterodorsal preoptic nucleus or posterodorsal medial amygdala, but not the parvicellular subparafascicular thalamus, disrupt mating in male gerbils. Physiol Behav 68:317-31
Pfaus, J G; Heeb, M M (1997) Implications of immediate-early gene induction in the brain following sexual stimulation of female and male rodents. Brain Res Bull 44:397-407
Ulibarri, C; Yahr, P (1996) Effects of androgens and estrogens on sexual differentiation of sex behavior, scent marking, and the sexually dimorphic area of the gerbil hypothalamus. Horm Behav 30:107-30

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