Overview
- After only a few hours without food, many virgin female mice rapidly became aggressive toward pups while behaving normally toward adults and prey.
- Experimentally activating AgRP appetite neurons drove pup-directed aggression in sated mice, and silencing these neurons reduced it in hungry mice, confirming causality.
- Projections from AgRP neurons suppressed activity in the medial preoptic area via neuropeptide Y, with HCN channels controlling the excitability that enables the behavioral switch.
- Responsiveness depended on reproductive state, as the oestradiol-to-progesterone ratio across the estrous cycle set MPOA sensitivity, and only about 60% of females showed aggression.
- The authors caution against direct human extrapolation and present the findings, published in Nature, as principles for how internal states are integrated to shape social behavior.