Overstimulating the NR1 subunits of the NMDA receptor showed effects similar to those from moderate drinking, whereas suppressing the NR1 subunits canceled out the effect of low, but steady consumption. These findings indicate that the NMDA receptor must be intact for the positive effects of alcohol to manifest, Kalev says. They speculate that the NMDA receptor is initially blocked by alcohol, causing the activity of the NR1 subunit to elevate as a compensatory response (thereby conferring heightened cognition).
Meir Stampfer, a professor of nutrition and epidemiology at the Harvard School of Public Health in Boston, says that the new work provides a stronger biological basis for studies that he and others have undertaken linking improved memory to moderate alcohol intake. "[This study] provides interesting evidence for a mechanism that may be operating at the NMDA receptor," he says, but quickly cautions: "It's better not to drink at all than to drink too much," as is also demonstrated by this study.