Professor, Neurobiology and Behavior
School of Biological Sciences

Behavioral neuroendocrinology; neuroendocrine control of male social behaviors; sexual differentiation of the brain and behavior

darwin.bio.uci.edu/neurobio/Faculty/Yahr/yahr.htm

The goal of our research is to understand how testosterone (T) acts on the brain to modify social behaviors of male mammals. In mammals and other vertebrates, T promotes the display of male social behaviors, especially those related to reproduction, by acting on the medial preoptic area (MPOA) of the hypothalamus. To understand how T affects the function of MPOA cells, we are studying its effects on sexually dimophic cell groups in the MPOA of gerbils and rats. Cells in the sexually dimorphic area (SDA) of the gerbil MPOA have receptors for T or its metabolites, respond to T enzymatically, metabolically, and morphologically, are essential for male sexual behavior and regulate mating, at least in part, through a projection to the retrorubral field of the midbrain. We are now using immunocytochemical methods to identify the neurotransmitters used in this circuit, are studying other circuits involving the SDA that affect mating and communication behaviors of males and are attempting to identify functionally analagous cell groups in rats.
We also study how sex differences in the structure of the brain develop as a result of sex differences in exposure to T during early development. We are particularly interested in the possibility that cell groups that are larger in males or that are present only in males, such as the gerbil SDApc, develop through hormonal prevention of naturally occurring cell death.

Yahr, P. and Gregory, J. E. (1993) The medial and lateral cell groups of the sexually dimorphic area of the gerbil hypothalamus are essential for male sexual behavior and act via separate pathways. Brain Res. 631:287-296.

Finn, P., De Vries, G. J. and Yahr, P. (1993) Efferent projections of the sexually dimorphic area of the gerbil hypothalamus: Anterograde identification and retrograde verification in males and females. J. Comp. Neurol. 338:491-520.

Finn, P.D. and Yahr, P. (1994) Projection of the sexually dimorphic area of the gerbil hypothalamus to the retrorubral field is essential for male sexual behavior: Role of A8 and other cells. Behav. Neurosci. 108:362-378.

Yahr, P., Finn, P.D., Hoffman, N.W. and Sayag, N. (1994) Sexually dimorphic cell groups in the medial preoptic area that are essential for male sex behavior and the neural pathways needed for their effects. Psychoneuroendo. 19:463-470.

Heeb, M.M. and Yahr, P. (1996) C-Fos immunoreactivity in the sexually dimorphic area of the hypothalamus and related brain regions of male gerbils after exposure to sex-related stimuli or performance of specific sexual behaviors. Neuroscience 72:1049-1071.

Heeb, M. M. and 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. 68:317-331.

Heeb, M. M. and Yahr, P. (2001) Anatomical and functional connections among cell groups in the gerbil brain that are activated with ejaculation. J. Comp. Neurol. 439:248-268.

Simmons, D. A. and Yahr, P. (2001) 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.

Simmons, D. A. and Yahr, P. (2003) GABA and glutamate in mating-activated cells in the preoptic area and medial amygdala of male gerbils. J. Comp. Neurol., in press.

Society for Behavioral Neuroendocrinology

Society for Neuroscience

Neurobiology and Behavior

Link to this profile
https://faculty.uci.edu/profile/?facultyId=2685

Last updated
08/18/2006