The DRN is an important region that integrates inputs from many systems, and can have far-reaching effects via the serotonergic projections. Binge drinking in adolescent P rats altered the expression of nearly 30% of the genes in the DRN, suggesting major alterations in DRN functioning. Numerous systems are affected, including multiple neurotransmitter systems, prominent among them the serotonin system (Table 1). Because the DRN has efferents to many brain regions, including the reward systems, the down-regulation of the serotonin system could have far-reaching effects on the brain and its response to alcohol. Neuropeptide systems (Table 2) are also prominently altered, in ways that indicate increased anxiety and decreased tolerance to stress at this time point, 3 h after the last exposure to alcohol. Stress and oxidative damage responses were also greatly affected. The large effects of repeated binges on gene expression in this key region could have major impacts on responses to alcohol and other stressors, which might persist into adulthood.
