Stress has profound effects on serotonin (5-HT) neurotransmission. The 5-HT transporter (5-HTT) provides the primary mechanism for termination of 5-HT neurotransmission and there is evidence to suggest it is under regulatory control of hormones released in response to stress. Stress is also linked to alcoholism. We recently reported (SfN 2004 Prog# 54.15) that the behavioral and neural effects of ethanol are potentiated in mice lacking the 5-HTT, further underlining the importance of 5-HTT function in determining drug response. Here we extend our investigation to examine the relationship between chronic stress, 5-HTT function and sensitivity to ethanol in vivo. Male C57BL/6J mice were exposed to chronic stress (daily 10 min forced swim for 14 days) or were unhandled (control). 24 hrs following the final stress session, mice were either anesthetized and prepared for chronoamperometry to measure 5-HT clearance in CA3 region of hippocampus, or tested in behavioral assays. Compared to control mice, 5-HT cleara...