Description:
Background: Adult neurogenesis occurs in the hippocampus and the subventricular zone. Recent evidence suggests that neurogenesis may also extend to other brain regions (hypothalamus, striatum, substantia nigra, cortex, and amygdala). Harnessing this intrinsic neurogenic potential may present a novel alternative for the replenishment of neurons lost in neurologic conditions. Methods: This descriptive review summarizes evidence supporting the classic and novel neurogenic zones present within the mammalian brain, discusses the functional significance of these new neurons, and the potential clinical applications of promoting intrinsic neurogenesis. Results: Some studies suggest new neurons originate from endogenous stem cell pools located within novel neurogenic regions while others show the migration from the subventricular zone to these regions. Regardless, adult neurogenesis is impacted by neurologic processes such as ischemia and neurodegenerative diseases and can be modulated by factors including neurotrophins, pharmacologic interventions, environmental exposures, exercise, and stem cell therapy. Conclusions: The discovery of functionally significant neurogenesis in adult brain regions has implications not only with regards to the function of these regions, but also for neuropathological conditions that affect them. Pharmacologic and stem cell-based strategies capable of promoting neurogenesis may have therapeutic potential following stroke or in the context of various neurodegenerative disorders.