Maternal oxytocin treatment at birth increases epigenetic age in male offspring [RNA-seq]
Rates of oxytocin use to induce or augment labor are increasing in the United States with little understanding of the impact on offspring development. Using a prairie vole animal model, we have shown that oxytocin administered to mothers can reach offspring brains with long lasting impacts on the development of social behaviors. Here, we examine the epigenetic and transcriptomic consequences of oxytocin exposure during birth in juvenile male offspring. First, we show that male offspring exposed to oxytocin at birth have increased epigenetic age compared to the saline exposed group. We also find 900 differentially methylated CpG sites (annotated to 589 genes), with 2 CpG sites (2 genes) remaining significant after correction for multiple comparisons. Differentially methylated CpG sites are involved in regulation of gene expression and neurodevelopment. Using RNA-sequencing we find 217 nominally differentially expressed genes (p<0.05) in nucleus accumbens, a brain region involved in reward circuitry and social behavior, including 6 genes that remain significantly differentially expressed after corrections for multiple comparisons. Finally, we show that maternal oxytocin administration leads to widespread alternative splicing in the nucleus accumbens. These results indicate that oxytocin exposure during birth has long lasting epigenetic consequences in the brain and warrant further investigation of how oxytocin administration impacts development and behavior throughout the lifespan. Overall design: To investigate how perinatal exposure to exogenous oxytocin impacts regulation of gene expression in the juvenile brain, we completed RNA-sequencing on nucleus accumbens from prairie voles born to mothers either injected with oxytocin or saline prior to birth.