Oct. 3 2012 12:00 AM

Charles Roselli, of the Oregon Health & Science University, is the fifth speaker in MSU’s semester-long series “Whom You Love: the biology of sexual orientation,” which aims to demonstrate that homosexuality is a natural occurrence in humans. Roselli is a professor in OHSU’s Department of Physiology and Pharmacology. His lecture includes content from his studies focusing on homosexual rams, which prompted a high-profile protest by PETA in 2007.

What general themes will your lecture cover? 

Homosexual behavior has been observed in hundreds of animal species. However, exclusive same-sex attraction is commonly thought to be a human trait. I plan to describe how sheep exhibit a diverse sex life and how some rams have an exclusive and lasting preference for other rams, making them a good model to study sexual orientation. Then I’ll explain how the brain differs between homosexual and heterosexual rams and what we’ve learned about the role that sex hormones play in wiring their brain before birth. We study rams because the information we obtain can provide important insights into the connections between brain physiology and sexual partner preferences. This is basic research, meaning that the goal is to gain knowledge and not be used for treatments. 

Could you briefly explain the testosterone/estrogen link in the developmental stage to homosexuality? 

Many of testosterone’s actions in the brain are produced only after it is converted to estrogen by the enzyme aromatase. This seems paradoxical: a “male” hormone that works by being changed to a “female” hormone. The sex distinction is meaningless to the brain — these are just molecules that have distinct biological actions. The intriguing link to sexual preferences is that the region of the brain that controls this behavior is enriched with aromatase in rams. However, we don’t understand yet how this all fits together.  

What was it like being on the business end of a PETA backlash? Did everything settle down eventually? 

My run-in with PETA was very stressful and disruptive. Because their campaign was based on false information and distortions, it became clear to me that PETA will stop at nothing in order to fulfill their mission to end all animal experimentation. I was fortunate that my university supported me and we were able to push back to correct PETA’s false and offensive claims. There were several news outlets here in the U.S. and abroad that did their own independent reporting and provided factual information about my research. The siege, which included letters, emails and even personal threats, lasted about nine months, but it’s been several years since I’ve had any more problems. I was actually quite surprised by the way the research was portrayed by PETA — we discovered that there are anatomical brain differences related to sex partner preferences. This should have promoted tolerance and understanding, not hate and anger.  

Why did you focus on sheep? 

Sheep make good test subjects because they exhibit naturally occurring variations in sexual preference and are surprisingly true to most of the important aspects of human sexual orientation. 

What inspired you to follow this line of research? 

As a young faculty member, I was invited to join a collaboration with my colleague Dr. Stormshak at Oregon State University and agricultural scientists in Idaho to study these unique rams. As a neuroendocrinologist, I was familiar with the groundbreaking work of Dr. LeVay, which showed that brains of gay and straight men were different. So, given the opportunity to work with these animals, my first question was whether their brains differed and, if so, how. True to scientific inquiry, one question led to another and the journey continues. 

What do you think the "Whom You Love" series could do for the social perception of homosexuality? 

I sincerely hope that by highlighting scientific facts about sexual orientation, this lecture series will help promote tolerance and understanding for all sexual minorities. 

Whom You Love
Charles Roselli, Ph.D
"Barnyard Insights into Sexuality"
Monday, 4 p.m.
Wells Hall 115B, MSU Campus

For more information on this series, go to whomyoulove.com.