Discriminative stimulus properties of ethanol in the rat: differential effects of selective and nonselective benzodiazepine receptor agonists.
Rats were trained to discriminate between ethanol (1.0 g/kg; 10% v/v) and saline under a fixed ratio 10 schedule of sweetened milk reinforcement. Both diazepam [nonselective, full benzodiazepine (BZ) receptors agonist] and bretazenil (nonselective, partial BZ receptor agonist) produced dose-dependent ethanol-appropriate responding (>75%). Neither diazepam nor bretazenil affected the response rate at the doses producing maximal generalisation from ethanol. In contrast, zolpidem (full BZ1 receptor agonist) and abecarnil (full BZ1/full or partial BZ2 receptor agonist) produced only moderate (<50%) ethanol-appropriate responding when tested up to doses that markedly decreased the overall response rate. These results suggest that: 1) there are no major differences between full and partial, nonselective BZ receptor agonists in their ability to substitute for 1.0 g/kg dose of ethanol; 2) stimulation of BZ1 receptors alone is not sufficient to produce ethanol-like discriminative stimulus effects in the rat.
Bienkowski
P
P
Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, Warsaw, Poland.
Iwinska
K
K
Stefanski
R
R
Kostowski
W
W
D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D000431:Ethanol / Q000494:pharmacology*; D058785:GABA-A Receptor Agonists; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D002492:Central Nervous System Depressants; D058785:GABA-A Receptor Agonists; D000431:Ethanol