title: Social context has differential effects on acquisition of nicotine self-administration in male and female rats.
abstract: BACKGROUND
  Smoking typically begins during adolescence or early adulthood in a social context, yet the role of social context in animal models is poorly understood.
  
  
  OBJECTIVE
  The present study examined the effect of social context on acquisition of nicotine self-administration.
  
  
  METHODS
  Sixty-day-old male and female Sprague-Dawley rats were trained to press a lever for nicotine (0.015 mg/kg, IV) or saline infusions (males only) on a fixed ratio (FR1) schedule of reinforcement across nine sessions in duplex chambers that were conjoined with either a solid wall or a wall containing wire mesh creating a social context between rat dyads (social visual, auditory, and olfactory cues). In a subsequent experiment, sex differences and dose-dependent effects of nicotine [0 (saline), 0.015 or 0.03 mg/kg, IV] were directly compared in rats trained in the isolated or social context on a schedule progressing from FR1 to FR3. These rats were given 20 sessions followed by 3 extinction sessions.
  
  
  RESULTS
  We consistently found transient social facilitation of low-dose nicotine self-administration in males during the first session. However, across training overall, we found social suppression of nicotine intake that was most prominent in females during later sessions.
  
  
  CONCLUSIONS
  Collectively, these findings suggest that at the age of transition from adolescence to adulthood, a social context enhances the initial reinforcing effects of nicotine in males, but protects against nicotine intake during later sessions especially in females. These findings highlight the importance of sex and social context in studying neural mechanisms involved in initiation of nicotine use.
authors.affiliation: Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA.
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Peartree
authors.affiliation: Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA.
authors.forename: Kayla N
authors.initials: KN
authors.lastname: Hatch
authors.affiliation: School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Julianna G
authors.initials: JG
authors.lastname: Goenaga
authors.affiliation: Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA.
authors.forename: Nora R
authors.initials: NR
authors.lastname: Dado
authors.affiliation: School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Hanna
authors.initials: H
authors.lastname: Molla
authors.affiliation: School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Dufwenberg
authors.affiliation: School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Allegra
authors.initials: A
authors.lastname: Campagna
authors.affiliation: School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Mendoza
authors.affiliation: Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA.|School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Timothy H C
authors.initials: THC
authors.lastname: Cheung
authors.affiliation: Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA.|School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Talboom
authors.affiliation: Department of Psychology, Arizona State University, P.O. Box 871104, Tempe, AZ, 85287-1104, USA. Janet.Neisewander@asu.edu.|School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ, 85287-4501, USA. Janet.Neisewander@asu.edu.
authors.forename: Janet L
authors.initials: JL
authors.lastname: Neisewander
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology; D003463:Cues; D004305:Dose-Response Relationship, Drug; D005260:Female; D008124:Locomotion / Q000187:drug effects / Q000502:physiology; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012646:Self Administration; D012727:Sex Characteristics; D012931:Social Environment
chemical_list: D009538:Nicotine
keywords: Adolescence; Dose-response; Drug self-administration; Extinction; Sex differences; Social behavior