Mean (±SEM) NaCl intakes (in milliliters) for DARPP-32 KO mice and WT mice during the taste-conditioning study. On trials 1–4 (conditioning), after 60 min access to 0.2 mNaCl, groups received either saline or ethanol (2 gm/kg or 4 gm/kg, i.p.). On trial 5, groups received a final 60 min access period to NaCl. Trials were conducted every 48 hr, and subjects received 2 hr access to water between trials.