FMR1 and fragile X syndrome: Additionally, there are both decreased GABAA1 subunit expression in neonatal mouse brains, as early as postnatal day 5 (Adusei et al., 2010) and decreased GABA concentrations were also found in multiple brain regions of neonatal and young Fmr1 KO mice (Davidovic et al., 2011; Braat et al., 2015) further substantiating the investigation of the GABAergic system for FXS treatment.