Relapse to alcohol use during abstinence or maladaptive eating habits during dieting is often provoked by stress. The anxiogenic drug yohimbine, a prototypical a2 adrenoceptor antagonist, which causes stresslike responses in humans and nonhumans, reliably reinstates alcohol and food seeking in a rat relapse model. Here, we studied the effect of the a1 adrenoceptor antagonist prazosin and the a2 adrenoceptor agonist guanfacine on yohimbineinduced reinstatement. In Exp. 1, we trained rats to selfadminister alcohol, and after extinction of alcoholreinforced lever pressing, we tested prazosin’s or guanfacine’s effect on yohimbineinduced reinstatement; we also examined prazosin’s effect on footshock stress induced reinstatement. In Exp. 2, we trained foodrestricted rats to selfadminister food pellets and first examined prazosin’s or guanfacine’s effects on foodreinforced responding, and then, after extinction of lever presses, on yohimbineinduced reinstatement. Prazosin blocked yohimbineinduced reinstatement of food and alcohol seeking, as well as footshockinduced reinstatement of alcohol seeking. Guanfacine attenuated yohimbineinduced reinstatement of alcohol seeking at the highest dose, but its effect on yohimbineinduced reinstatement of food seeking was not significant. Neither prazosin nor guanfacine affected highrate foodreinforced responding. Results demonstrate an important role of postsynaptic a1 adrenoceptors in stressinduced reinstatement of alcohol and food seeking.
Effect of prazosin and guanfacine on stress-induced reinstatement of food and alcohol seeking in rats.
CIFANI, Carlo;
2011-01-01
Abstract
Relapse to alcohol use during abstinence or maladaptive eating habits during dieting is often provoked by stress. The anxiogenic drug yohimbine, a prototypical a2 adrenoceptor antagonist, which causes stresslike responses in humans and nonhumans, reliably reinstates alcohol and food seeking in a rat relapse model. Here, we studied the effect of the a1 adrenoceptor antagonist prazosin and the a2 adrenoceptor agonist guanfacine on yohimbineinduced reinstatement. In Exp. 1, we trained rats to selfadminister alcohol, and after extinction of alcoholreinforced lever pressing, we tested prazosin’s or guanfacine’s effect on yohimbineinduced reinstatement; we also examined prazosin’s effect on footshock stress induced reinstatement. In Exp. 2, we trained foodrestricted rats to selfadminister food pellets and first examined prazosin’s or guanfacine’s effects on foodreinforced responding, and then, after extinction of lever presses, on yohimbineinduced reinstatement. Prazosin blocked yohimbineinduced reinstatement of food and alcohol seeking, as well as footshockinduced reinstatement of alcohol seeking. Guanfacine attenuated yohimbineinduced reinstatement of alcohol seeking at the highest dose, but its effect on yohimbineinduced reinstatement of food seeking was not significant. Neither prazosin nor guanfacine affected highrate foodreinforced responding. Results demonstrate an important role of postsynaptic a1 adrenoceptors in stressinduced reinstatement of alcohol and food seeking.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
