Microglia depletion and alcohol: Transcriptome and behavioral

Purpose: Alcohol abuse induces changes in microglia morphology and immune function, but whether microglia initiate or simply amplify the harmful effects of alcohol exposure is still a matter of debate. Here we determined microglia function in acute and voluntary drinking behaviors using a colony stimulating factor 1 receptor inhibitor (PLX5622) and 3'UTR biased-sequencing. Therefore, The purpose of this study was to provide insight regarding microglia depletion and voluntary alcohol consumption. Methods: We performed 3'UTR biased transcriptome sequencing (3'Tag-seq) on total homogenate isolated from the prefrontal cortex (PFC) of C57BL6/J mice following microglia depletion and chronic every-other-day alcohol consumption. Results: Differential expression analysis and WGCNA network analysis revealed that although many immune genes have been implicated in alcohol abuse, downregulation of microglia genes does not necessitate changes in alcohol intake. Finally, we show that microglia depletion and chronic alcohol result in compensatory upregulation of ethanol-responsive, reactive astrocyte genes, indicating astrocytes may play a critical role in regulation of these alcohol behaviors. Conclusion:Taken together our behavioral and transcriptional data indicate that microglia are not the primary effector cell responsible for regulation of acute and voluntary alcohol behaviors. In addition, our data represents a novel resource for groups interested in transcriptional effects of microglia depletion after alcohol consumption. Overall design: Illumina 3'UTR biased-sequencing of total homogenate from PFC of mice following chronic alcohol consumption and microglia depletion