AUTHOR=Angelyn Hailley , Loney Gregory C. , Meyer Paul J. 

TITLE=Nicotine Enhances Goal-Tracking in Ethanol and Food Pavlovian Conditioned Approach Paradigms

JOURNAL=Frontiers in Neuroscience

VOLUME=Volume 15 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2021.561766

DOI=10.3389/fnins.2021.561766

ISSN=1662-453X

ABSTRACT=Rationale: Nicotine promotes alcohol intake through pharmacological and behavioral interactions.  As an example of the latter, nicotine can facilitate approach toward food- and alcohol-associated stimuli (“sign-tracking”) in lever-Pavlovian conditioned approach (PavCA) paradigms. However, we recently reported that nicotine can also enhance approach towards locations of reward delivery (“goal-tracking”) triggered by ethanol-predictive stimuli when the location of ethanol delivery is non-static (i.e. a retractable sipper bottle). 
Objective: To determine whether the non-static nature of the reward location could have biased the development of goal-tracking in our previous study (Loney et al., 2019), here we assessed the effect of nicotine in a lever-PavCA paradigm wherein the location of ethanol delivery was static (i.e. a stationary liquid receptacle). Then, to determine whether nicotine’s enhancement of goal-tracking is unique to ethanol-predictive stimuli, we assessed the effect of systemic nicotine on approach triggered by food-predictive stimuli in a lever-PavCA paradigm.
Methods: Long-Evans rats were used in two PavCA experiments wherein a lever predicted the receipt of ethanol (15% v/v; experiment 1) or food (experiment 2) into a stationary receptacle. Prior to testing, rats were administered nicotine (0.4 mg/kg s.c.) or saline systemically.
Results: In both experiments, nicotine increased measures of goal-, but not sign-, tracking.
Conclusions: Nicotine can facilitate approach behavior without enhancing the incentive value of reward-predictive stimuli. As such, conceptualization of the mechanisms by which nicotine effects behavior must be expanded to explain an enhancement of goal-tracking by nicotine.