Assessment of the aversive and rewarding effects of alcohol in Fischer and Lewis rats.
BACKGROUND
Application of the Fischer-Lewis genetic model of drug abuse to the study of alcohol's motivational properties has been limited.


OBJECTIVE
To assess the aversive and rewarding effects of ethanol in Fischer and Lewis rats.


METHODS
Fischer and Lewis rats underwent a four-trial combined conditioned taste aversion/conditioned place preference procedure (CTA/CPP; 0, 1, 1.25, or 1.5 g/kg IP ethanol). Others received 0, 1, or 1.5 g/kg followed by tail blood sampling at 15-, 60- and 180-min post-injection. In additional groups, hypothermia to 0, 1.5, and 3 g/kg was assessed before and 30- and 60-min post-injection.


RESULTS
All alcohol-treated groups except low-dose Lewis acquired CTA after one trial. Fischer rats developed stronger CTAs than Lewis at 1.25 and 1.5 g/kg. Ethanol-induced reward in taste or place conditioning was not evident in either strain. Lewis animals showed overall higher peak blood alcohol concentrations, but hypothermia did not vary by strain.


CONCLUSIONS
Compared to Fischer, Lewis rats are less sensitive to alcohol's aversive effects as assessed in the CTA paradigm. The behavioral differences observed are not due to hypothermia, but pharmacokinetic differences may contribute. These data underscore the importance of genetic factors and the aversive effects of initial drug exposures in modeling vulnerability to abuse. In addition to its application with other drugs, the Fischer-Lewis model may be useful for investigating the biobehavioral bases of alcohol abuse.
Roma
Peter G
PG
Psychopharmacology Laboratory, Department of Psychology, American University, Washington, DC 20016, USA. PeteRoma@gmail.com
Flint
Wesley W
WW
Higley
J Dee
JD
Riley
Anthony L
AL
D000428:Alcohol Drinking / Q000235:genetics / Q000523:psychology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005838:Genotype; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D012439:Saccharin / Q000008:administration & dosage; D019966:Substance-Related Disorders / Q000235:genetics / Q000523:psychology; D013649:Taste / Q000187:drug effects
D002492:Central Nervous System Depressants; D000431:Ethanol; D012439:Saccharin