CX3CR1 and autism spectrum disorder: Ablation of microglial C-X3-C motif chemokine receptor 1 (CX3CR1) in mice resulted in phenotypes associated with autism spectrum disorders including cognitive impairment (Kreisel et al., 2014), social withdrawal (Zhang et al., 2014) and resistance to chronic psychological stress-induced anhedonia- and anxiety-like phenotype (Wohleb et al., 2014; Milior et al., 2016).