Early in the 20th century, bird dealers discovered that female birds injected with the sex hormone testosterone sang more complicated songs, like their male counterparts. A Johns Hopkins research team decided to investigate how female canary brains changed with exposure to testosterone to affect their behavior.
Greg Ball, Ph.D., professor of psychological and brain sciences at the Zanvyl Krieger School of Arts and Sciences, says birds learn to sing by mimicking their fathers, and use memory to recall songs, which is similar to how people learn to talk. Therefore the researchers quantified the levels of learning and memory genes — thought to affect the development of male-typical singing behavior — in the brains of female birds treated with testosterone for one to five weeks.
The researchers discovered increased levels of the gene for the glutamate receptor, NMDAr, in the region of the brain that controls singing. NMDAr detects glutamate, one of the brain's chemical messengers, and is important for song learning.
"We want to continue to explore how internal hormonal and external environmental cues normally affect behavior by changing the brain," says Ball. "Understanding what happens under different hormonal conditions in the brain, even in birds, provides insight on what happens in the case of humans with mental disorders, where problems in the brain adversely affect behavior."
Poster#: 503.09/EEE57, Hall F-J, Monday, Oct. 15, 2012, 1-2 p.m. CSTAuthors: B. A. Alward, T. J. Stevenson, K. Y. Peng, M. L. Rouse, W. D. Mayes, J. Balthazart, G. F. Ball
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Poster#: 503.10/EEE58, Hall F-J, Monday, Oct. 15, 2012, 2-3 p.m. CSTAuthors: M. L. Rouse, Jr., S. Dangelmajer, G. F. Ball