Wired on Steroids: Sexual Differentiation of the Brain and Its Role in the Expression of Sexual Partner Preferences

How can genetic phenomena and embryonic endocrine exert influence on the determination of sexual orientation?

  • Date: 25 OCTOBER 2022  from 17:30 to 19:00

  • Event location: In presence and online event

  • Type: Lectures

One of the more controversial questions concerning neurobiology of behavior relates to the origins of sexual orientation and the influence exerted by biology and the social environment. This lecture will focus on biological mechanisms involved in the determination of sexual orientation in animals and also presumably in humans. Scientific evidence suggests that sexual orientation, both homosexual and heterosexual, is under the control of embryonic endocrine and genetic phenomena in which there is little room for individual choice. Prof. Roselli will discuss his ongoing studies of sheep, a unique mammalian model in which roughly 8% of rams exhibit a naturally-occurring exclusive sexual preference for other rams. He will present evidence that sheep have a sexually dimorphic nucleus (SDN) in the brain that is larger in female-oriented rams (gynophilic) than in male-oriented rams and ewes (androphilic). He will demonstrate that the small size of the SDN in male-oriented rams reflects lower exposure to androgens during gestation and could be responsible for their attraction to other rams. He will also present new evidence that neuropeptide signaling mechanisms in the hypothalamus are key for regulating the degree of androgen exposure in the male fetus. Finally, Prof. Roselli will discuss the significance of these studies for understanding possible biological underpinnings of human sexuality.



Charles Eugene Roselli

Oregon Health and Science University

Visit Prof. Roselli's web page

PhD students and researchers who are interested may request an attendance certificate.