Reinstatement of alcohol-seeking by priming injections of alcohol and exposure to stress in rats.
Previous studies using a reinstatement procedure have found that acute reexposure to the self-administered drug and exposure to footshock stress reinstate heroin and cocaine seeking after prolonged drug-free periods. Here we tested whether these findings generalize to alcohol-taking behavior. Male rats were initially allowed to consume alcohol in a two-bottle choice procedure (water versus alcohol) for 30 min/day for 36 days. Rats were then trained for 60 min/day in operant chambers to press a lever for the drug (0.13 ml of 12% w/v of an alcohol solution) for up to 55 days. After stable drug-taking on a fixed-ratio-3 schedule of reinforcement was obtained, lever pressing for alcohol was extinguished by terminating drug delivery for 4-9 days. Reinstatement of drug seeking was then determined after non-contingent priming injections of alcohol (0.24 and 0.48 g/kg; given i.p. and orally) or exposure to intermittent footshock stress (5 and 15 min; 0.8 mA). Priming injections of alcohol produced a modest dose-dependent reinstatement of drug seeking, whereas footshock stress potently reinstated extinguished alcohol seeking. In contrast, similar parameters of footshock failed to reinstate extinguished sucrose-taking behavior in rats previously trained to lever press for sucrose pellets. These findings extend previous reports on reinstatement of cocaine and heroin seeking by a footshock stressor and by priming drug injections. It also appears that the reinstatement procedure provides an appropriate methodology to study relapse to alcohol-taking behavior in the drug-free state.
Lê
A D
AD
Biobehavioral Research Department, Addiction Research Foundation of Ontario, Toronto, Canada.
Quan
B
B
Juzytch
W
W
Fletcher
P J
PJ
Joharchi
N
N
Shaham
Y
Y
D000284:Administration, Oral; D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D012646:Self Administration; D013312:Stress, Physiological
D002492:Central Nervous System Depressants; D000431:Ethanol