Oral ethanol self-administration in inbred Roman high- and low-avoidance rats: Gradual versus abrupt ethanol presentation

Outbred Roman high-avoidance rats are known to consume more ethanol than inbred Roman low-avoidance rats. To determine whether ethanol consumption in inbred strains could be modulated by experiential factors, preference for a target 10% ethanol concentration was tested after either the gradual introduction of ethanol in increasing concentrations or the abrupt introduction of the target concentration. Whereas high-avoidance rats consumed more ethanol at lower concentrations, consumption and preference for ethanol over water were not differential across strains and administration procedure (gradual vs. abrupt). At the 4% concentration, ethanol was preferred over water by Roman high-avoidance rats, but water was preferred over ethanol by Roman low-avoidance rats. Ethanol consumption and preference for a 10% concentration appear to be immune to modification by either the gradual or abrupt ethanol presentation.

► Genetics and experiential factors affect ethanol consumption. ► Rats selected for high avoidance performance consume more ethanol than low-avoidance rats. ► At low ethanol concentrations, high-avoidance rats prefer ethanol over water. ► At low ethanol concentrations, low-avoidance rats prefer water over ethanol.