BBB Seminar: Heather A. Cameron

Maturation and function of new neurons in the adult hippocampus

Heather A. Cameron
National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA

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 production in the adult hippocampus, the activation of the new neurons by experience, 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 inhibiting adult neurogenesis on behavior. We have found that mice lacking adult neurogenesis show heightened responses to psychosocial stress; it takes longer for corticosteroid levels to return to baseline levels after stress in these mice. In addition, they show increased depressive-like behavior in stressful tests or after being stressed. We are interested in learning more about how the new neurons normally buffer against depressive-like behavior. In addition, we are investigating how the stress buffering property of new neurons relates to their role in learning and memory.

Host: Marit Bakke , Department of Biomedicine