New research done in collaboration between David Anderson, PhD, Seymour Benzer Professor of Biology, Howard Hughes Medical Institute investigator and director of the Tianqiao and Chrissy Chen Institute for Neuroscience and a team at the Allen Institute for Brain Science recently discovered rare brain cell types that are unique to male mice and other types that are unique to female mice. The sex-specific cells were found in the region of the brain that governs both aggression and mating behaviors although their functional significance remains to be explained. A paper describing the research appears online on October 17 in the journal Cell.