The temporal and volumetric components of stress induced drinking in rats.

Abstract

Two experiments are presented which describe the temporal and volumetric changes in ethanol consumption with rats exposed to recurring schedules of inescapable random shock stress. The animals in Experiment I had an ethanol and water choice and the data demonstrated cumulative increases in voluntary ethanol consumption which occurred immediately after the shock schedule. The post shock changes occurred with both 5% and 10% V/V ethanol, were specific to the appearance of shock and were not reflected by measures of total daily ethanol intake. Experiment II exposed rats to extended 22 hr. stress sessions and each animal had four simultaneous fluid choices available: water, saccharin. 1% W/V, ethanol 5% V/V, and ethanol 10% V/V. Temporal intake patterns for both 5% and 10% ethanol showed pronounced peaks for the interval immediately following the shock schedule. A progressive shift of intake from 5% to 10% ethanol was also evidenced with increasing time under shock, while saccharin and water intake decreased. Blood ethanol levels during shock increased significantly from baseline for all animals and ranged from 30 to 162 mg/100 ml. The results are interpreted as a relationship between voluntary ethanol intake and escape from the consequences of stress.