Nicotine affects ethanol-conditioned taste, but not place, aversion in a simultaneous conditioning procedure

LONEY, GREGORY C.; PAUTASSI, RICARDO MARCOS; KAPADIA, DELNA; MEYER, PAUL J.

ALCOHOL

ELSEVIER SCIENCE INC

Año: 2018 vol. 71 p. 47 - 55

0741-8329

The conditioned taste aversion (CTA) induced by ethanol is a key factor limiting ethanol intake.Nicotine, a drug co-consumed with ethanol, may decrease this aversion by modulating theunconditioned effects of ethanol or by disrupting the association between ethanol and itsassociated cues. This study analyzed ethanol-induced CTA and conditioned place aversion (CPA)in Long Evans rats with sub-chronic exposure to nicotine. The rats were treated with nicotine (0.0or 0.4 mg/kg) three times before conditioning (on lickometer training sessions three, four and five)and across conditioning days. During the conditioning the rats were given ethanol (1.3 g/kg)preceded and followed by presentation of a taste (NaCl) and tactile (rod or hole floors)conditioned stimuli (CS+), respectively. On CS− conditioning days, the rats were given vehicleand exposed to alternative stimuli. Three CTA and CPA testing sessions were then conducted. Itwas found that nicotine reduced ethanol-induced CTA and enhanced locomotor activity, but didnot significantly modify the magnitude of ethanol-induced CPA. The effects of nicotine on CTAwere observed during both conditioning and testing sessions, and were specific to the NaCl CS+,having no effect on reactivity to water. The dissociation between the effect of nicotine on ethanolinducedCTA and CPA suggests that nicotine does not alter ethanol?s motivational properties bygenerally increasing its positive rewarding effects; nor does it blunt all aversive-like responding tothis drug. Instead, nicotine may impede ethanol-induced CTA induced by ethanol by disruptingthe neural underpinnings of this specific form of associative learning.