Male P rats (n = 51 in Study 1; n = 20 in Study 2) from the 60th generation of selective breeding for alcohol preference served as subjects. The rats were individually housed in stainless-steel hanging cages in an isolated vivarium with controlled temperature (21 ± 1 °C) and a 12-h light/dark cycle (lights off at 1000 hours). Standard rodent chow (Laboratory Rodent Diet #7001, Harlan Teklad, Madison, WI) and water were available ad libitum at all times throughout the study. All experimental procedures were approved by the Indiana University Institutional Animal Care and Use Committee and conducted in strict compliance with the NIH Guide for the Care and Use of Laboratory Animals.
