Grant: Discovery Grants Program - Individual

Exposure to a deprived or adverse early rearing environment, often called "early adversity", has been shown to have lasting effects on how individuals both react to stress and learn. Based on existing animal models, we know that some of these effects are directly due to changes in the brain that occur during important early stages of development. For example, continually removing rat pups from their mothers causes physical changes in the neurohormonal system that deals with stress- the HPA axis. Specifically, receptors for stress hormones, located in brain regions that tell the body to "turn off" a stress response, are reduced in maternally-separated rats. The end effect of this change is that these animals are more anxious, may be more susceptible to disease, and may have impaired learning abilities as they age. I propose to study the effects of early adversity in two relatively new animal models: the Yucatan miniature pig (mini-pig) and the European Starling. The mini-pig will serve as an interesting contrast to the well-studied rat pup, since piglets have more mature brains at birth. As well, pigs learn various spatial tasks more quickly than rats, and their learning processes may be more similar to humans. Birds, such as the European Starling, are an interesting comparison when investigating how "prenatal" stress experienced by a mother later affects her offspring. This is because, unlike in mammals, stress hormones in the mother bird can only affect her chicks directly when she is forming the egg before it is laid. Thus, the mini-pig and bird models allow us to study the respective differences in the ways that prenatal (physiological) and postnatal (maternal) care factors influence offspring development. This research will potentially be of interest to areas ranging from animal welfare (e.g., livestock husbandry in commercial pig production), human healthcare (e.g., modeling effects of prenatal glucocorticoid therapy), and child development (e.g., modeling effects of child neglect or suboptimal care on learning and memory processes).