Like a champion fighter gaining confidence after each win, a male mouse that prevails in several successive aggressive encounters against other male mice will become even more aggressive in future encounters. This phenomenon is interesting to scientists who study behavioral neuroscience because aggression is an innate behavior in the brain. Now a team of Caltech researchers have discovered that the hard-wired neural circuits governing aggression in mice are strengthened following their victories in aggressive encounters, and they have identified a learning mechanism operating in the hypothalamus—a brain region traditionally viewed as the source of instincts, rather than learning.
The research was done in the lab of David Anderson, Seymour Benzer Professor of Biology, Tianqiao and Chrissy Chen Institute for Neuroscience Leadership Chair, Howard Hughes Medical Institute Investigator, and director of the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech.