Subjects were adult (> 90 days old), ethanol-naïve, male P rats from the S52 generation. The rats were single-housed in hanging stainless steel wire-mesh (bottom and front) cages on a reverse 12 hr/12 hr dark-light cycle (light offset at 1000 hr). Animals had ad libitum access to food. Rats were randomly divided into three groups (n = 9/group): the 1st group had access to water as their sole fluid, the 2nd group had continuous/daily, concurrent, free-choice access to 15% and 30% (v/v) ethanol and water, and the 3rd group had bout-like, concurrent access to 15% and 30% ethanol, with water available ad libitum. The bout-like group experienced a multiple scheduled access (MSA) protocol, such that they received three 1-hr access periods each separated by 2 hr starting at the beginning of the dark cycle (i.e., 1000-1100, 1300-1400, and 1600-1700 hr). The MSA animals were given ethanol access in 5-day blocks (Monday—Friday), with each block separated by 2 days without ethanol. Measurements of water and ethanol intake, and body weights were taken Monday through Friday at 0900 hr; ethanol intakes, for
