Galanin neurons in the medial preoptic area govern parental behavior

Mice display robust, stereotyped behaviors toward pups: virgin males typically attack pups, while virgin females and sexually experienced males and females display parental care. We show here that virgin males genetically impaired in vomeronasal sensing do not attack pups and are parental. Further, we uncover a subset of galanin-expressing neurons in the medial preoptic area (MPOA) that are specifically activated during male and female parenting, and a different subpopulation activated during mating. Genetic ablation of MPOA galanin neurons results in dramatic impairment of parental responses in males and females and affects male mating. Optogenetic activation of these neurons in virgin males suppresses inter-male and pup-directed aggression and induces pup grooming. Thus, MPOA galanin neurons emerge as an essential regulatory node of male and female parenting behavior and other social responses. These results provide an entry point to a circuit-level dissection of parental behavior and its modulation by social experience.