Our data suggest that acute ethanol enhances GABAergic neurotransmission in MOR N40 AD-iNs. Furthermore, it has been established (Lieberman et al., 2012) that chronic ethanol exposure in human iPS-derived neural cells caused significant increases in mRNA expression of NMDA receptor subunit genes. This was only observed after 7 days of chronic ethanol exposure in neurons generated from alcoholic individuals, and not from controls (Lieberman et al., 2012). We next aimed to address whether a CIE paradigm (a model that mimics binge-like levels of brain ethanol exposure) directly alters GABA release in AD-iNs, and whether the effect depends on MOR N40D variants (Fig. 5). The CIE paradigm is illustrated in Fig. 5A, as adapted from a previous study (Guo, Chen, Carreon, & Qiang, 2012). CIE in vitro results in the evaporation of ethanol from culture media containing ethanol over the period of 24 h prior to replenishment. We measured the ethanol concentration at 0, 12, and 24 h after media replenishment (Fig. 5B) and found the half-life of 75 mM ethanol in solution is ~7 h (Fig. 5C). Interestingly, the sister
