Both male and female hormones play role in making men masculine, research shows
April 28, 2010
WEDNESDAY, April 28 (HealthDay News) — Gender-specific behavior patterns are often chalked up to testosterone in men and estrogen in women, but a new study explains why the hormone issue isn’t so clear cut.
The male hormone testosterone doesn’t work in ways that had been assumed when it comes to masculinizing the brain during development and making males behave a certain way when they’re adults, researchers found.
“It was known that testosterone and estrogen are essential for typical male behaviors in many vertebrate species,” study senior author Dr. Nirao M. Shah, of the anatomy department at the University of California, San Francisco, said in a news release. “However, how these two hormones interact to control masculinization of the brain and behavior remained to be established.”
Shah and colleagues genetically engineered mice to get rid of a pathway thought to play a role in how animals become masculinized. Yet, they found that the mutant mice still acted like males — fighting and marking territory — but with some differences. In particular, the extent and frequency of typical male behaviors varied between the mutant mice and the other mice.