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Nicotine Produces a High‐Approach, Low‐Avoidance Phenotype in Response to Alcohol‐Associated Cues in Male Rats
Author(s) -
Loney Gregory C.,
Angelyn Hailley,
Cleary Liam M.,
Meyer Paul J.
Publication year - 2019
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.14043
Subject(s) - nicotine , psychology , conditioning , cue reactivity , incentive salience , saline , taste aversion , classical conditioning , addiction , self administration , alcohol , pharmacology , neuroscience , taste , anesthesia , craving , medicine , chemistry , biochemistry , statistics , mathematics
Background Nicotine and alcohol use are highly comorbid. Modulation of drug‐paired extrinsic and intrinsic cues likely plays a role in this interaction, as cues can acquire motivational properties and augment drug seeking. The motivational properties of cues can be measured through Pavlovian conditioning paradigms, in which cues either elicit approach following pairing with the reinforcing properties of alcohol or elicit avoidance following pairing with the aversive consequences of alcohol. The present experiments tested whether nicotine would enhance the incentive properties of an appetitive ethanol (EtOH) cue and diminish the avoidance of an aversive EtOH cue in Pavlovian paradigms. Methods In experiment 1, male Long‐Evans rats with or without prior chronic intermittent access to EtOH were administered nicotine or saline injections prior to Pavlovian conditioned approach (Pav CA ) sessions, during which conditioned approach to the cue (“sign‐tracking”) or the EtOH delivery location (“goal‐tracking”) was measured. In experiment 2, male Long‐Evans rats were administered nicotine or saline injections prior to pairing a flavor cue with increasing doses of EtOH ( i.p .) in an adaptation of the conditioned taste avoidance ( CTA ) paradigm. Results Results from Pav CA indicate that, regardless of EtOH exposure, nicotine enhanced responding elicited by EtOH‐paired cues with no effect on a similar cue not explicitly paired with EtOH. Furthermore, nicotine reduced sensitivity to EtOH‐induced CTA , as indicated by a rightward shift in the dose–response curve of passively administered EtOH. The ED 50 , or the dose of EtOH that produced a 50% reduction in intake relative to baseline, was significantly higher in nicotine‐treated rats compared to saline‐treated rats. Conclusions We conclude that nicotine increases the approach and diminishes the avoidance elicited by Pavlovian cues paired, respectively, with the reinforcing and aversive properties of EtOH consumption in male rats. As such, nicotine may enhance alcoholism liability by engendering an attentional bias toward cues that predict the reinforcing outcomes of drinking.