Assistant Professor of Neurobiology (in Psychiatry)
Department of Psychiatry
Division of Systems Neuroscience & Sackler Institute for Developmental Psychobiology
Host: Darcy Kelley
Title: Hippocampal Neurogenesis and Stress Resilience
Abstract: Adult neurogenesis in the dentate gyrus of the hippocampus is highly regulated by environmental influences, and functionally implicated in behavioral responses to stress and antidepressant treatment in rodents and in humans. However, how adult-born neurons regulate information processing in the hippocampus to protect from stress-induced anxiety-like behavior is unknown. I will present data showing that neurogenesis confers resilience to chronic stress by inhibiting the activity of mature granule cells in the ventral dentate gyrus (vDG), a subregion implicated in mood regulation. We found that chemogenetic inhibition of adult-born neurons in the vDG promotes susceptibility to social defeat stress while increasing neurogenesis confers resilience to chronic stress. Using in vivo calcium (Ca2+) imaging in freely moving mice to record neuronal activity from large cell populations in the vDG, we found that the dentate gyrus contains a subpopulation of “stress responsive-cells” that are active preferentially during stressful situations or while mice explore anxiogenic environments. Increased neurogenesis results in a decrease in the activity of this stress-responsive cell population, and this effect is necessary and sufficient to confer stress resilience. Our results suggest that neurogenesis-mediated regulation of hippocampal function may be a key factor in determining individual levels of vulnerability to stress and related psychiatric disorders.