Impaired glutamate receptor-mediated plasticity is implicated in FXS and an imbalance of excitation and inhibition at the neuronal circuit level has been found in the mouse model of FXS [Fmr1 knockout (KO) mice; Bear et al., 2004; Bassel and Warren, 2008; Gibson et al., 2008; Harlow et al., 2010; Gonçalves et al., 2013; Zhang et al., 2014]. This evidence concerns the gene FMR1 and fragile X syndrome.