OXTR and neurodevelopmental disorder: Intriguingly, consistent with our observation with MOPr and OTR regulation, GF male mice show more pronounced social impairments (Hoban et al., 2016) and alterations in neurochemistry (Clarke et al., 2013) compared to females, which has led to the hypothesis that sex differences in gut microbiota may reflect the higher incidence of neurodevelopmental disorders such as ASD among males.