Neurogenesis

Most neurons in the mammalian brain are produced during the embryonic period. In contrast, the granule cell population of the dentate gyrus of the hippocampal formation is produced during an extended period that begins during gestation and continues well into adulthood. The production of new granule neurons is suppressed by stress. These observations suggest that stressful experiences during postnatal development and adulthood have the potential to alter significantly both the structure and function of the hippocampal formation. Because the hippocampus plays a key role in learning and memory, a decrease in the production of granule neurons during development may have a negative impact on learning and memory in adulthood. © 2007