The effects of nicotine on ethanol-induced conditioned taste aversions in Long-Evans rats.
BACKGROUND
Overall drug acceptability is thought to be a function of the balance between its rewarding and aversive effects, the latter of which is reportedly affected by polydrug use.


OBJECTIVE
Given that nicotine and alcohol are commonly co-used, the present experiments sought to assess nicotine's impact on ethanol's aversive effects within a conditioned taste aversion design.


METHODS
Experiment 1 examined various doses of nicotine (0, 0.4, 0.8, 1.2 mg/kg) to determine a behaviorally active dose, and experiment 2 examined various doses of ethanol (0, 0.5, 1.0, 1.5 g/kg) to determine a dose that produced intermediate aversions. Experiment 3 then examined the aversive effects of nicotine (0.8 mg/kg) and ethanol (1.0 g/kg) alone and in combination. Additionally, nicotine's effects on blood alcohol concentrations (BAC) and ethanol-induced hypothermia were examined.


RESULTS
Nicotine and ethanol combined produced aversions significantly greater than those produced by either drug alone or the summed aversive effects of the individual compounds. These effects were unrelated to changes in BAC, but nicotine and ethanol combined produced a prolonged hypothermic effect which may contribute to the increased aversions induced by the combination.


CONCLUSIONS
These data demonstrate that nicotine may interact with ethanol, increasing ethanol's aversive effects. Although the rewarding effects of concurrently administered nicotine and ethanol were not assessed, these data do indicate that the reported high incidence of nicotine and ethanol co-use is unlikely due to reductions in the aversiveness of ethanol with concurrently administered nicotine. It is more likely attributable to nicotine-related changes in ethanol's rewarding effects.
Rinker
Jennifer A
JA
Psychopharmacology Laboratory, Department of Psychology, American University, Washington, DC 20016, USA. jennifer.rinker@gmail.com
Busse
Gregory D
GD
Roma
Peter G
PG
Chen
Scott A
SA
Barr
Christina S
CS
Riley
Anthony L
AL
D000818:Animals; D001245:Association Learning / Q000187:drug effects; D001362:Avoidance Learning / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects; D003214:Conditioning, Classical / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D000431:Ethanol / Q000097:blood / Q000633:toxicity*; D005260:Female; D007275:Injections, Intravenous; D009538:Nicotine / Q000494:pharmacology* / Q000633:toxicity; D051381:Rats; D020318:Rats, Long-Evans; D013649:Taste / Q000187:drug effects*
D000431:Ethanol; D009538:Nicotine