Epigenetic Hangover

Adolescents who indulge in binge-drinking may alter patterns of gene expression in their still-developing brains, causing long-lasting behavioral changes. To model adolescent binge-drinking in humans, scientists at the University of Illinois at Chicago intermittently exposed 28-day-old rats to alcohol. The rats showed increased anxiety-like behaviors, and they drank more alcohol in adulthood, long after exposure to alcohol had ended. The rats’ amygdalae, the scientists found, contained increased levels of a histone-modifying protein called HDAC2. It causes DNA to coil extra-tightly around histone-complex “spools,” lessening the accessibility of certain genes. One such gene, the scientists indicated appears to be needed for the formation of new synaptic connections.