Mechanistic and Circuit-Based Studies of Infant-Directed Behaviors

Abstract

Male mice display stereotyped behaviors towards pups that vary depending on their mating status: virgin males typically attack pups, while sexually experienced males display parental care. This behavioral phenomenon is referred to as the ‘parental switch’. This thesis details the projection patterns of MPOA Gal+ neurons to known target sites, in order to better understand how this cell population regulates the many behaviors needed for pup-directed care. In addition, we present brain areas that send projections unto a population of cells modulating pup-directed neglect/attack. Further, I explore the role of adult neurogenesis in preventing infanticide and promoting pup-directed care in male mice. Since mating is necessary for the parental switch, this was done by quantifying rates of proliferation and integration in mated animals as compared to control animals. Lastly, I show functional studies that prevented adult neurogenesis from occurring during and after mating and subsequently tested the response to pups. Ablation of adult neurogenesis near the time of mating led to an increase in pup-directed attacks, supporting the hypothesis that adult neurogenesis underlies the behavioral changes associated with the parental switch.