title: Nicotine intake and problem solving strategies are modified during a cognitively demanding water maze task in rats.
abstract: BACKGROUND
  Nicotine is the major addictive component in tobacco, and despite well-established adverse health effects of tobacco addiction, some smokers have difficulty quitting. The acute cognitive enhancement and/or the amelioration of the cognitive disruption during withdrawal that some smokers experience after smoking are among important factors that hinder quit attempts. The animal model presented in the current study is comparable to the human smoking condition although nicotine intake routes are different. Rats were exposed to a free choice of oral nicotine starting at adolescence, and given a water maze (WM) task as adults. This design allowed us to see if rats alter their nicotine intake during the WM task and if nicotine preference and intake modify abilities and strategies rats use for problem solving.
  
  
  METHODS
  Male and female rats were exposed to a free choice of oral nicotine/water for 24weeks, starting at five weeks of age. After this period, they were selected based on their nicotine intake and, together with control animals that received only water, were subjected to a place-learning task in the WM. Free-choice nicotine exposure continued during WM testing. Following acquisition, the probe trial presented the rats with a choice between using two different strategies for problem solving.
  
  
  RESULTS
  Nicotine supported acquisition and rats increased their nicotine intake during WM testing; this effect was more pronounced in male rats with minimum nicotine preference and intake. Furthermore, nicotine modified the "female type" strategy in solving the place-learning task and nicotine treated female rats, unlike control females, behaved like males.
  
  
  CONCLUSIONS
  The increase in nicotine intake during mental engagement, and the sexually dimorphic effect of nicotine on problem solving strategies that we have observed in rats, may suggest that implementing sex-specific smoking cessation approaches, especially under stressful and cognitively demanding conditions, may be useful in helping smokers quit.
authors.affiliation: Ege University, Center for Brain Research, Bornova, Izmir, Turkey.
authors.forename: Tanseli
authors.initials: T
authors.lastname: Nesil
authors.affiliation: Ege University, Center for Brain Research, Bornova, Izmir, Turkey; Ege University, School of Medicine, Department of Physiology, Bornova, Izmir, Turkey.
authors.forename: Lutfiye
authors.initials: L
authors.lastname: Kanit
authors.affiliation: Ege University, Center for Brain Research, Bornova, Izmir, Turkey. Electronic address: sakire.pogun@ege.edu.tr.
authors.forename: Sakire
authors.initials: S
authors.lastname: Pogun
mesh_terms: D000818:Animals; D003071:Cognition / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D004327:Drinking Behavior / Q000187:drug effects; D005260:Female; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D011340:Problem Solving / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D015430:Weight Gain / Q000187:drug effects
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine
keywords: Nicotine; Preselected rats; Sex differences; Strategy; Stress; Water maze