Alterations in Adult Neurogenesis Persist after Alcohol Exposure

The recent discovery of adult neurogenesis from dividing neural stem cells changes the framework in which we consider brain plasticity. Adult neurogenesis from neural stem cells is well accepted in at least two regions of the adult brain, the dentate gyrus of the hippocampus and the subventricular zone of the anterior lateral ventricles. This new concept of synaptic plasticity, and its regulation, produces a novel direction to understanding brain function and dysfunction in chronic alcoholism. Neural stem cell proliferation and neurogenesis are regulated by the many of same factors that are common effects/defects in alcohol addiction. Indeed, we have shown recently that alcohol inhibits adult neurogenesis. Chronic alcohol exposure, during intoxication, effects neural stem cell proliferation and newborn cell survival in the production of new neurons (neurogenesis). However, it is not known what happens during the abstinence period immediately after the cessation of chronic alcohol. Neural adaptations to chronic exposure may contribute to the long-term effect of alcohol on adult neurogenesis. Thus, we propose to investigate the effect of alcohol on adult neurogenesis following the cessation of chronic alcohol, and specifically consider the role of alcohol withdrawal in neural stem/progenitor cell proliferation, differentiation and survival. Our recent report supports the hypothesis that alcohol affects adult neurogenesis by increasing neural stem/progenitor cell proliferation in the dentate gyrus at different time points after the cessation of alcohol. As well, alcohol may alter newborn cell survival and differentiation. The results from this series of studies will show how alcohol affects neural plasticity in the adult after the cessation of chronic alcohol. These discoveries will further our understanding of how chronic alcohol affects neuroanatomy and neural plasticity during abstinence and explains a potential new mechanism underlying recovery during abstinence.