Ischemia-induced neurogenesis of neocortical layer 1 progenitor cells

• DOI: 10.1038/nn.2473
• Publication Date: 2009-12-27T17:56:59Z
• Authors: Koji Ohira; Takahiro Furuta; Hiroyuki Hioki; Kouichi C Nakamura; Eriko Kuramoto; Yasuyo Tanaka; Nobuo Funatsu; Keiko Shimizu; Takao Oishi; Motoharu Hayashi; Tsuyoshi Miyakawa; Takeshi Kaneko; Shun Nakamura
• Keywords: Male; Neurons; 0301 basic medicine; Time Factors; Neurogenesis; Somatosensory Cortex; Brain Ischemia; Rats; Adult Stem Cells; 03 medical and health sciences; Prosencephalon; Synapses; Animals; Rats, Wistar; Stem Cell Niche; gamma-Aminobutyric Acid; Cell Proliferation

Adult mammalian neurogenesis occurs in the hippocampus and the olfactory bulb, whereas neocortical adult neurogenesis remains controversial. Several occurrences of neocortical adult neurogenesis in injured neocortex were recently reported, suggesting that neural stem cells (NSCs) or neuronal progenitor cells (NPCs) that can be activated by injury are maintained in the adult brain. However, it is not clear whether or where neocortical NSCs/NPCs exist in the brain. We found NPCs in the neocortical layer 1 of adult rats and observed that their proliferation was highly activated by global forebrain ischemia. Using retrovirus-mediated labeling of layer 1 proliferating cells with membrane-targeted green fluorescent protein, we found that the newly generated neurons were GABAergic and that the neurons were functionally integrated into the neuronal circuitry. Our results suggest that layer 1 NPCs are a source of adult neurogenesis under ischemic conditions.