Neurogenesis
|
|
"Neurogenesis" literally means "birth of neurons". Neurogenesis is most prevalent during pre-natal development and is the process by which neurons are created to populate the growing brain.
Adult Neurogenesis
New neurons are continually born throughout adulthood in predominantly two regions of the brain. One is in the sub-ventricular zone lining the lateral ventricles where the new cells migrate to the olfactory bulb via the Rostral Migratory Stream, and the other is in the dentate gyrus of the hippocampus. Many of these newborn cells will die shortly after their birth, but a number of them become functionally integrated into the surrounding brain tissue.
The function of adult neurogenesis is not certain - although there is good evidence that hippocampal adult neurogenesis is important for learning and memory. Activities such as learning and voluntary exercise seem to promote their survival and successful integration into the existing hippocampus. On the other hand, stimuli such as chronic stress can decrease their proliferation.
Neurogenesis has recently been linked to the beneficial actions of certain anti-depressants, suggesting a connection between decreased hippocampal neurogenesis and depression.