Melissa Holmes

The overarching research focus in my lab is the relationship between adult neural plasticity and social status. We use naked mole-rats to study this question because they exhibit the most rigidly organized social and reproductive hierarchy among mammals. Naked mole-rats are eusocial, which is essentially an extreme form of co-operative breeding; they live in large colonies of up to 300 individuals in which reproduction is restricted to a single breeding female (called the queen) and one to three breeding males. Importantly, breeders of both sexes are socially dominant over all other members of the colony; the remaining members of the colony, called subordinates, are kept non-reproductive by the presence of the queen. However, this reproductive suppression is not permanent: adult subordinates can become breeders if they are removed from the colony and paired with an opposite sex mate. Given that these animals are remarkably long-lived (up to 30 years in captivity), this reveals an exceptional sustained potential for plasticity mediated by the social environment. My research program can be described as three inter-related lines of research, which ultimately come together to highlight the importance of social environment in shaping brain and behaviour in adulthood. First and foremost, we study the neuroendocrine mechanisms associated with social status and reproductive suppression. Second, we are interested in individual differences in social phenotype. Third, we investigate how status or changes in the social environment regulate adult neurogenesis.