Cahoy et al. (2008) identified genes enriched in different cell types that could serve as characteristic markers of those cells. We examined the differentially expressed genes for evidence of patterns that might reflect a change in relative numbers of several cell types in the PAG of these animals. Genes that are characteristic of neurons and astrocytes (Cahoy et al., 2008) showed a similar ratio of over- and under-expression as the full set of genes, close to 50%, indicating that there was no substantial change in the contribution of those cells to the PAG. But of the genes characteristic of oligodendrocytes, 80% were decreased, suggesting a decrease in the number and/or function of oligodendrocytes as a result of the alcohol exposure.
