AUTHOR=Marshall S. Alex , McClain Justin A. , Wooden Jessica I. , Nixon Kimberly TITLE=Microglia Dystrophy Following Binge-Like Alcohol Exposure in Adolescent and Adult Male Rats JOURNAL=Frontiers in Neuroanatomy VOLUME=Volume 14 - 2020 YEAR=2020 URL=https://www.frontiersin.org/journals/neuroanatomy/articles/10.3389/fnana.2020.00052 DOI=10.3389/fnana.2020.00052 ISSN=1662-5129 ABSTRACT=Microglia are dynamic cells that have roles in neuronal plasticity as well as in recovery responses following neuronal injury. Although many hypothesize that hyperactivation of microglia contributes to alcohol-induced neuropathology, in other neurodegenerative conditions disruption of normal microglial processes also contributes to neuronal loss, particularly as microglia become dystrophic or dysfunctional. Based on the observation of a striking, abnormal morphology in microglia during binge-like ethanol exposure, the present study investigated the impact of excessive ethanol exposure on microglia number and dystrophic morphology in a model of alcohol dependence that includes neurodegeneration in both adult and adolescent rats. Following 2- and 4-day binge ethanol exposure, the number of microglia were decreased in the hippocampus and the perirhinal and entorhinal cortices of both adult and adolescent rats. Furthermore, a significant number of microglia with a dystrophic morphology were observed in ethanol-exposed tissue, accompanied by a significant decrease in brain-derived neurotrophic factor expression in the hippocampus. Together these findings suggest another means by which microglia may contribute to alcohol-induced neurodegeneration, specifically dystrophic microglia and/or loss of microglia may disrupt homeostatic and recovery mechanisms. These results demonstrate that microglia also degenerate with excessive alcohol exposure, which has important implications for understanding the role of microglia - and specifically their contributions to plasticity and neuronal survival - in neurodegenerative disease.