Effects of cocaine-induced sensitization on ethanol drinking: sex and strain differences.

Sensitization induced by repeated drug exposure has been proposed to increase 'wanting' the drug and to facilitate the transition from moderate to excessive drug intake. The present study examined the effects of cocaine-induced sensitization on ethanol-drinking behavior in male and female rats from different strains. In experiment 1, rats were pretreated with six injections of saline or cocaine (10 mg/kg, i.p.), spaced by 3-day intervals, and were subsequently allowed access to ethanol intake in an unrestricted free-choice procedure. In experiment 2, rats had acquired ethanol-drinking behavior and were exposed to the sensitizing treatment described previously or were left undisturbed. Subsequently, all animals again had access to ethanol. Whatever the sex and strain concerned, sensitized and control animals did not differ in either the acquisition or the maintenance of ethanol-drinking behavior, suggesting that cocaine-induced behavioral sensitization does not modify ethanol intake. The present results also confirm the sex- and strain-dependent character of alcohol intake and of the 'alcohol deprivation effect'.