Reduced ethanol drinking following selective cortical interneuron deletion of the GluN2B NMDA receptors subunit.

N-Methyl-d-aspartate receptors (NMDAR) are involved in the regulation of alcohol drinking, but the contribution of NMDAR subunits located on specific neuronal populations remains incompletely understood. The current study examined the role of GluN2B-containing NMDARs expressed on cortical principal neurons and cortical interneurons in mouse ethanol drinking. Consumption of escalating concentrations of ethanol was measured in mice with GluN2B gene deletion in either cortical principal neurons (GluN2B(CxNULL)) or interneurons (GluN2B(InterNULL)), using a two-bottle choice paradigm. Results showed that GluN2B(InterNULL), but not GluN2B(CxNULL), mice consumed significantly less ethanol, at relatively high concentrations, than non-mutant controls. In a second paradigm in which mice were offered a 15% ethanol concentration, without escalation, GluN2B(CxNULL) mice were again no different from controls. These findings provide novel evidence for a contribution of interneuronal GluN2B-containing NMDARs in the regulation of ethanol drinking.