To care or not to care

The behaviour of adult mice towards pups varies depending on gender and sexual experience. The activity of a population of neurons in the hypothalamus of the brain has now been found to regulate these differing responses. See Article p.325 Sexual experience brings radical change in how male mice behave with pups — virgin males attack them whereas experienced fathers display parental care. Now Catherine Dulac and colleagues show that virgin males with impaired pheromone sensing do not attack pups. Even more spectacularly, the authors identify a subset of hypothalamic neurons expressing the neuropeptide galanin whose activation in virgin males suppresses aggression and induces pup grooming. Genetic ablation of galanin-expressing neurons results in dramatic impairment of both maternal and paternal responses to pups. The molecular identification of a neuronal population controlling parental behaviour in both males and females is likely to attract wide interest from both neuroscientists and ethologists.