A) Acute injection of 2 g/kg increased footslips in all groups compared to 0 g/kg, however the EtOH and BOTH (i.e. EtOH + CAFF) had smaller increases, indicative of tolerance to the ataxic effects of ethanol (n=7–10/grp. B) A higher dose of ethanol (3 g/kg) increased footslips in the VEH, EtOH and CAFF groups. Footslips recorded in the BOTH group were similar to those of the 0 g/kg group indicating that the history of ethanol/caffeine exposure produced tolerance to high doses of ethanol (n=9–12/grp). C) Acute challenge with ethanol and caffeine also produced ataxia similarly to the results shown in Panel A. The CAFF mice showed an increase in footslips compared to the VEH mice, indicating that the history of caffeine increased the ataxic response to the drug combination (n=12–20/grp). Data are means ± S.E.M. (*=p<0.05 vs. vehicle challenge, ^=p<0.05 vs. vehicle history, #=p>0.05 vs. 0 g/kg).