For the ASD FOXG1 syndrome haploinsufficiency model, in which local inhibitory tone is decreased during the early juvenile critical period, a decrease in GABAergic activity exacerbates the social behavior deficits, whereas re-balancing the E/I ratio by enhancing GABAergic tone ameliorates the social impairments (Fig. 6k, scores compared), thus pinpointing this developmental stage as promising for therapeutic intervention. The gene discussed is FOXG1; the disease is Down syndrome.