Newborn neurons in the dentate gyrus that survive to 28 d are considered to be permanently incorporated into hippocampal circuitry (Kempermann et al., 2003). To investigate long term effects of binge alcohol exposure on newly formed cells, cell fate (survival and phenotype) was analyzed 28 d after alcohol exposure. In this study, BrdU was administered 1 h following the last dose of ethanol, and the rats were maintained for 28 additional days (4D+28). To examine cell phenotype, tissue was subjected to triple immunofluorescent labeling for BrdU, a neuron-specific protein (NeuN) and astroglia-specific protein (GFAP; Figure 5). Fifty BrdU+ cells per dentate gyrus were examined for colabeling with either NeuN or GFAP and expressed as the percent of BrdU+ cells showing a neuronal, glia or other phenotype. The majority of BrdU+ cells in both groups (Con, n=5; EtOH, n=4) expressed a neuronal phenotype (Figure 5a). Also, a slight but significant increase was observed in the percentage of cells that did not colabel for either NeuN or GFAP, labeled as “other.” Two recent reports in adults suggest that these cells could be
