Adult neurogenesis in the hypothalamus: evidence, functions, and implications.

Neurogenesis occurs in the adult brain in a constitutive manner under physiological circumstances within two regions: the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricles. In contrast to these two so-called neurogenic areas, other regions of the brain were considered to be primarily non-neurogenic in nature, implying that no new neurons were formed there under normal conditions. Recently, low proliferative activity was reported in the hypothalamus and the cell layers surrounding the third ventricle. This review summarizes recent evidence for adult neurogenesis in the hypothalamus, and points out the potential contributions of these new neurons to neural processing. We also discussed some technical considerations in investigating neurogenesis in the adult hypothalamus. It is believed that the hypothalamus could serve as a new source and target for stem cell transplantation.