FOOD-DEPRIVATION INCREASES COCAINE-INDUCED CONDITIONED PLACE PREFERENCE AND LOCOMOTOR-ACTIVITY IN RATS

Food-deprivation increases the reinforcing efficacy of cocaine and oth er drugs within self-administration experiments. In this study, the ef fects of food-deprivation on cocaine-induced conditioned place prefere nce were investigated. Male Sprague-Dawley rats were assigned to one o f two feeding conditions: satiated (with ad libitum food) or deprived (maintained at 80% of free-feeding body weights). During conditioning trials, on alternate days, rats received IP injections of cocaine (0.0 , 2.5, 5.0, or 10.0 mg/kg; n=12 per dose group) and were confined for 30 min in one of two distinct environments. On intervening days, the s ame rats were injected with saline and confined for 30 min in the oppo site environment. After four cocaine and four saline trials, a 15-min choice test (with no injections) was given. During this time, the rats were able to move freely through a passageway between both environmen ts. Relative to the food-satiated rats, the food-deprived rats showed a greater conditioned preference for the cocaine-paired environment du ring the choice test, greater cocaine-induced locomotor activity durin g conditioning trials, and a greater degree of sensitization to the ac tivating effects of cocaine across conditioning trials. This study ext ends the general findings of food deprivation-induced increases in the reinforcing efficacy of cocaine to include the conditioned place pref erence paradigm.