|Geert J. De Vries
Professor of Psychology, University of Massachusetts
Ph.D.: University of Amsterdam, The Netherlands
Sexual Differentiation of the Brain
Gonadal hormones control our behavior throughout life. During development, they determine whether we will show male- or female-typical behavioral patterns. In adulthood, they stimulate or inhibit certain functions and behaviors, for example, sexual behavior. Our lab studies the cellular basis of these effects. We have identified a sexually dimorphic group of neurons that make the neuropeptide vasopressin. Males have twice as many of these neurons as do females. We have also shown that these neurons are strongly influenced by gonadal hormones. They only express vasopressin if gonadal hormones are present. We study the process of sexual differentiation of these neurons, and the functional significance of their sexual dimorphism and steroid responsiveness. By following the development of these cells and by manipulating the levels of gonadal hormones, we have found that sex difference in gonadal hormone levels during development cause the sex difference in vasopressin cell number. The difference does not appear to be caused by more vasopressin cells being born in males than in females, nor by more vasopressin cells dying in females than in males. Rather, in females, more cells either lose the ability to produce vasopressin during development, or never develop the ability in the first place.
We are currently studying which factors are important in this developmental decision. In addition, we are studying the function of the sex difference in the vasopressin neurons. One unexpected result is that this system tends to promote as well as prevent sex differences in behavior. For example, it appears to stimulate aggressive behavior more in males than in females, whereas it prevents sex differences in parental responsiveness in biparental species such as prairie voles. In the latter case, the sex difference apparently compensates for hormonal and physiological differences that could have induced undesirable differences in behavior. Our research, therefore, ranges from the molecular to the behavioral level. Students have the option of restricting themselves to one particular level or spanning the entire range.
Lonstein, J. S., B. D. Rood and G. J. De Vries (2002). "Parental responsiveness is feminized after neonatal castration in virgin male prairie voles, but is not masculinized by perinatal testosterone in virgin females." Horm Behav 41(1): 80-7.
Quadros, P. S., V. Lopez, G. J. De Vries, W. C. Chung and C. K. Wagner (2002). "Progesterone receptors and the sexual differentiation of the medial preoptic nucleus." J Neurobiol 51(1): 24-32.
Chung, W. C., G. J. De Vries and D. F. Swaab (2002). "Sexual differentiation of the bed nucleus of the stria terminalis in humans may extend into adulthood." J Neurosci 22(3): 1027-33.
Lonstein, J. S. and G. J. De Vries (2000). "Influence of gonadal hormones on the development of parental behavior in adult virgin prairie voles (Microtus ochrogaster)." Behav Brain Res 114(1-2): 79-87.
Lonstein, J. S. and G. J. De Vries (2000). "Maternal behaviour in lactating rats stimulates c-fos in glutamate decarboxylase-synthesizing neurons of the medial preoptic area, ventral bed nucleus of the stria terminalis, and ventrocaudal periaqueductal gray." Neuroscience 100(3): 557-68.
Lonstein, J. S. and G. J. De Vries (2000). "Sex differences in the parental behavior of rodents." Neurosci Biobehav Rev 24(6): 669-86.
Lonstein, J. S., B. Greco, G. J. De Vries, J. M. Stern and J. D. Blaustein (2000). "Maternal behavior stimulates c-fos activity within estrogen receptor alpha-containing neurons in lactating rats." Neuroendocrinology 72(2): 91-101.
Chung, W. C., D. F. Swaab and G. J. De Vries (2000). "Apoptosis during sexual differentiation of the bed nucleus of the stria terminalis in the rat brain." J Neurobiol 43(3): 234-43.
Han, T. M. and G. J. De Vries (1999). "Neurogenesis of galanin cells in the bed nucleus of the stria terminalis and centromedial amygdala in rats: a model for sexual differentiation of neuronal phenotype." J Neurobiol 38(4): 491-8
Jin, X., L. P. Shearman, D. R. Weaver, M. J. Zylka, G. J. de Vries and S. M. Reppert (1999). "A molecular mechanism regulating rhythmic output from the suprachiasmatic circadian clock." Cell 96(1): 57-68