Heather Cameron, Ph.D.

The dentate gyrus is one of only two brain regions that continue to produce large numbers of new neurons during adulthood. The goal of our research is to understand the function of adult neurogenesis by studying the regulation of granule cell development, the activation of the new neurons, and the behavioral consequences of inhibiting neurogenesis.

One focus of our work is understanding the activation of granule cells at different ages. New granule cells mature over several weeks, but it is unclear whether they become functional while they are immature, and both highly excitable and highly plastic, or whether they contribute to hippocampal function only after they mature and have properties more like the rest of the granule cell population. This issue is important, because it is related to the larger question of whether granule cells continue to be generated in order to increase the size of the granule cell population or whether the young neurons have a different function than the mature granule cells. If young granule cells do have a unique function, what is the time window during which they perform this function?

Another aspect of our work involves exploring the effects of adult neurogenesis on behavior. We have found that mice lacking adult neurogenesis show heightened physiological and behavioral responses to psychosocial stress and decreased ability to adapt to their level of anxiety-like behavior or caution in environments where threats are unpredictable. In addition, we find that rats and mice lacking ongoing neurogenesis show decreased motivation in difficult tasks and decreased shifting of attention to changes in the environment. We are investigating how the effects on stress, motivation, and attention are related to each other and to a role in learning and memory.

Dr. Cameron received her B.S. from Yale University and her Ph.D. from the Rockefeller University, where she worked with Bruce McEwen and Elizabeth Gould examining neurogenesis in the adult rat dentate gyrus. During a postdoctoral fellowship with Ron McKay at NINDS, she determined the magnitude of adult neurogenesis in the dentate gyrus and investigated the effects of stress hormones on neurogenesis in the aging rat hippocampus. Dr. Cameron joined the Mood and Anxiety Disorders Program at NIMH as an Investigator in 2001.