title: Performance on a strategy set shifting task in rats following adult or adolescent cocaine exposure.
abstract: BACKGROUND
  Neuropsychological testing is widespread in adult cocaine abusers, but lacking in teens. Animal models may provide insight into age-related neuropsychological consequences of cocaine exposure.
  
  
  OBJECTIVE
  The objective of the present study is to determine whether developmental plasticity protects or hinders behavioral flexibility after cocaine exposure in adolescent vs. adult rats.
  
  
  METHODS
  Using a yoked-triad design, one rat controlled cocaine delivery and the other two passively received cocaine or saline. Rats controlling cocaine delivery (1.0 mg/kg) self-administered for 18 sessions (starting P37 or P77), followed by 18 drug-free days. Rats next were tested in a strategy set shifting task, lasting 11-13 sessions.
  
  
  RESULTS
  Cocaine self-administration did not differ between age groups. During initial set formation, adolescent-onset groups required more trials to reach criterion and made more errors than adult-onset groups. During the set shift phase, rats with adult-onset cocaine self-administration experience had higher proportions of correct trials and fewer perseverative + regressive errors than age-matched yoked-controls or rats with adolescent-onset cocaine self-administration experience. During reversal learning, rats with adult-onset cocaine experience (self-administered or passive) required fewer trials to reach criterion, and the self-administering rats made fewer perseverative + regressive errors than yoked-saline rats. Rats receiving adolescent-onset yoked-cocaine had more trial omissions and longer lever press reaction times than age-matched rats self-administering cocaine or receiving yoked-saline.
  
  
  CONCLUSIONS
  Prior cocaine self-administration may impair memory to reduce proactive interference during set shifting and reversal learning in adult-onset but not adolescent-onset rats (developmental plasticity protective). Passive cocaine may disrupt aspects of executive function in adolescent-onset but not adult-onset rats (developmental plasticity hinders).
authors.affiliation: Department of Psychological and Brain Sciences, Boston University, 64 Cummington Mall, Boston, MA, 02215, USA, kkantak@bu.edu.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Kantak
authors.forename: Nicole
authors.initials: N
authors.lastname: Barlow
authors.forename: David H
authors.initials: DH
authors.lastname: Tassin
authors.forename: Madeline F
authors.initials: MF
authors.lastname: Brisotti
authors.forename: Chloe J
authors.initials: CJ
authors.lastname: Jordan
mesh_terms: D000367:Age Factors; D000818:Animals; D003042:Cocaine / Q000008:administration & dosage*; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D012193:Reversal Learning / Q000187:drug effects; D012646:Self Administration; D012718:Set, Psychology
chemical_list: D018765:Dopamine Uptake Inhibitors; D003042:Cocaine