title: The effect of nicotine on sign-tracking and goal-tracking in a Pavlovian conditioned approach paradigm in rats.
abstract: BACKGROUND
  Nicotine (NIC) potently increases operant responding for non-NIC reinforcers, and this effect may depend on drug-mediated increases in incentive motivation. According to this hypothesis, NIC should also potently increase approach to Pavlovian-conditioned stimuli associated with rewards.
  
  
  OBJECTIVE
  The present studies explored the effects of NIC on Pavlovian-conditioned approach responses.
  
  
  METHODS
  To do so, liquid dippers were used to deliver an unconditioned stimulus (US; 0.1 ml sucrose) after presentation of a conditioned stimulus (CS; 30 s illumination of a stimulus light)-both the CS and US were presented in receptacles equipped to monitor head entries.
  
  
  RESULTS
  In experiment 1, the CS and US were presented in the same receptacle, but NIC pretreatment (0.4 mg/kg base) did not increase conditioned approach responses. Delivery of the sucrose US was then shifted to receptacle in a different location. All rats learned to approach the new US location (goal-tracking) at similar rates. Approach to the CS receptacle (sign-tracking) declined for saline-pretreated rats, but NIC pretreatment increased sign-tracking. In experiment 2, NIC pretreatment increased sign-tracking when the CS and US were spatially separated during acquisition. In experiment 3, NIC pretreatments were replaced with saline, but the effect of NIC persisted for an additional 24 test sessions.
  
  
  CONCLUSIONS
  The findings suggest that NIC increases incentive motivation and that this effect is long-lasting, persisting beyond the pharmacological effects of NIC.
authors.affiliation: Department of Psychology, East Tennessee State University, Johnson City, PO Box 70649, TN 37641, USA. palmatier@mail.etsu.edu
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Palmatier
authors.forename: Kimberley R
authors.initials: KR
authors.lastname: Marks
authors.forename: Scott A
authors.initials: SA
authors.lastname: Jones
authors.forename: Kyle S
authors.initials: KS
authors.lastname: Freeman
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Wissman
authors.forename: A Brianna
authors.initials: AB
authors.lastname: Sheppard
mesh_terms: D000818:Animals; D001288:Attention / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects*; D006040:Goals; D008297:Male; D009042:Motivation; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine