title: Single trial nicotine conditioned place preference in pre-adolescent male and female rats.
abstract: The mean age of first voluntary tobacco inhalation is 12.3 years (DiFranza et al., 2004). 60% of smokers start smoking before the age of 14 and 90% are dependent before reaching the age of 19. Females are typically more sensitive to nicotine than males yet few studies examine the effects of nicotine on the reward systems in pre-adolescent female subjects. This study utilized the single trial conditioned place preference (CPP) test in very young (postnatal day 25-27) rats of both sexes. Latent effects on anxiety and amphetamine response were determined 5 and 7 days following a second nicotine exposure. Results show that 0.05 mg/kg nicotine induced CPP in females following a single trial while both sexes showed CPP following the 0.5 mg/kg dose. Five days later, rats dosed with 0.05 mg/kg show increased time on the open arm of the elevated plus maze, an anxiolytic response. While baseline activity was increased in nicotine-exposed males 7 days following dosing, amphetamine response was not affected by the treatments in either sex. Therefore, our data suggest that young females are more sensitive to nicotine reward than males supporting a heightened sensitivity of the mesolimbic dopamine system in very young females. However, alterations in baseline activity were only seen in males suggesting that different components of the system are affected by nicotine in each sex. An anxiolytic response to nicotine 5 days after dosing may suggest that this very young age group is uniquely affected by this very low nicotine dose. Clearly, nicotine has substantial acute and lasting effects during pre-adolescence at doses substantially lower than seen at older ages as reported by others. These effects, which could potentially result from cigarette or e-cigarette smoking by 11-12 year old children , focus attention on the vulnerability of this age group to nicotine.
authors.affiliation: Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States; Iowa State University, Ames, IA, United States.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Edwards
authors.affiliation: Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States; Iowa State University, Ames, IA, United States.
authors.forename: Nathan
authors.initials: N
authors.lastname: Konz
authors.affiliation: Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States; Macaulay Honors College at Brooklyn College, Brooklyn, NY, United States.
authors.forename: Zahava
authors.initials: Z
authors.lastname: Hirsch
authors.affiliation: Scientific Computing Center, State University of New York, Downstate Medical Center, Brooklyn, NY, United States.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Weedon
authors.affiliation: Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States. Electronic address: Diana.dow-edwards@downstate.edu.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Dow-Edwards
mesh_terms: D000367:Age Factors; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005731:Ganglionic Stimulants / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D013037:Spatial Behavior / Q000187:drug effects*
chemical_list: D000697:Central Nervous System Stimulants; D005731:Ganglionic Stimulants; D009538:Nicotine; D000661:Amphetamine
keywords: Amphetamine challenge; Anxiety; Locomotor activity; Pre-adolescent rats; Reward systems; Sex-differences