Warsaw high-preferring (WHP) and Warsaw low-preferring (WLP) lines of rats selectively bred for high and low voluntary ethanol intake: Preliminary phenotypic characterization

The Warsaw High Preferring (WHP) and Warsaw Low Preferring (WLP) lines were bred from Wistar foundation stock to obtain lines of rats that differ in their preference for ethanol solutions. The WHP line has met several major criteria for an animal model of alcoholism. The WHP rats voluntarily drink excessive amounts of ethanol while the WLP rats consume negligible amounts of ethanol. The WHP rats attain physiologically active blood ethanol concentrations with chronic free-choice drinking. They also develop subtle but visible signs of physical dependence (the withdrawal signs). The patterns of ethanol consumption in WHP and WLP lines are stable in time and independent of the manner of access to ethanol solutions. Notably, when exposed to the increasing ethanol concentrations WHP rats gradually increased total ethanol intake whereas the WLP rats consumed invariably very low amounts of ethanol. Furthermore, the WHP rats show an increased responsiveness to the stimulatory effects of low dose of ethanol.