A vasopressin circuit that modulates sex-specific social interest and anxiety-like behavior in mice.

The function of sex differences in the brain is poorly understood. Here we test the function of one of the most consistently found sex differences in vertebrate brains, the male-biased vasopressin projections from the bed nucleus of the stria terminalis. Using optogenetic techniques, we demonstrate that these cells and their projection to the lateral septum are much more important in driving male than female social investigation. These studies make a strong contribution to understanding how sexually dimorphic circuitry controls social behavior.