Role of acetaldehyde in ethanol-induced conditioned taste aversion in rats.
BACKGROUND
In spite of many recent studies on the effects of acetaldehyde, it is still unclear whether acetaldehyde mediates the reinforcing and/or aversive effects of ethanol.


OBJECTIVE
The present study reexamined the role of acetaldehyde in ethanol-induced conditioned taste aversion (CTA). A first experiment compared ethanol- and acetaldehyde-induced CTA. In a second experiment, cyanamide, an aldehyde dehydrogenase inhibitor, was administered before conditioning with either ethanol or acetaldehyde to investigate the effects of acetaldehyde accumulation.


METHODS
A classic CTA protocol was used to associate the taste of a saccharin solution with either ethanol or acetaldehyde injections. In experiment 1, saccharin consumption was followed by injections of either ethanol (0, 0.5, 1.0, 1.5 or 2.0 g/kg) or acetaldehyde (0, 100, 170 or 300 mg/kg). In experiment 2, the rats were pretreated with either saline or cyanamide (25 mg/kg) before conditioning with either ethanol or acetaldehyde.


RESULTS
Both ethanol and acetaldehyde induced significant CTA. However, ethanol produced a very strong CTA relative to acetaldehyde that induced only a weak CTA even at toxic doses. Cyanamide pretreatments significantly potentiated ethanol- but not acetaldehyde-induced CTA.


CONCLUSIONS
The present results indicate that ethanol-induced CTA does not result from brain acetaldehyde effects. In contrast, it is suggested that the reinforcing effects of brain acetaldehyde might actually reduce ethanol-induced CTA. Our results also suggest that the inhibition of brain catalase activity may contribute to the potentiating effects of cyanamide on ethanol-induced CTA.
Escarabajal
M Dolores
MD
Area de Psicobiología, Universidad de Jaén, 23071, Jaén, Spain.
De Witte
Philippe
P
Quertemont
Etienne
E
D000079:Acetaldehyde / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D000427:Alcohol Deterrents / Q000008:administration & dosage / Q000494:pharmacology; D000428:Alcohol Drinking / Q000378:metabolism* / Q000523:psychology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002755:Choice Behavior / Q000187:drug effects; D003213:Conditioning, Psychological / Q000187:drug effects*; D003484:Cyanamide / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects; D000431:Ethanol / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012439:Saccharin / Q000008:administration & dosage; D012965:Sodium Chloride / Q000008:administration & dosage; D014867:Water / Q000008:administration & dosage
D000427:Alcohol Deterrents; D014867:Water; D000431:Ethanol; D003484:Cyanamide; D012965:Sodium Chloride; D012439:Saccharin; D000079:Acetaldehyde