Suppression of adult neurogenesis leads to an increased hypothalamo-pituitary-adrenal axis response.

Stress and glucocorticoids are among the strongest inhibitors of adult hippocampal neurogenesis. Despite the known role of the hippocampus in negative feedback regulation of the hypothalamo-pituitary-adrenal axis, whether the loss of hippocampal neurogenesis affects this inhibition has not been examined. Here we tested whether suppression of adult neurogenesis affected the hypothalamo-pituitary-adrenal axis response. Our results show that suppression of neurogenesis leads to a potentiated hypothalamo-pituitary-adrenal axis response after an exposure to a mild stressor. This study suggests that suppressed neurogenesis regulates the hypothalamo-pituitary-adrenal axis response.