title: Effect of age on methylphenidate-induced conditioned taste avoidance and related BDNF/TrkB signaling in the insular cortex of the rat.
abstract: BACKGROUND
  Drug use and abuse is thought to be a function of the balance between its rewarding and aversive effects, such that the rewarding effects increase the likelihood of use while the drug's dissociable aversive effects limit it. Adolescents exhibit a shift in this balance toward reward, which may ultimately lead to increased use. Importantly, recent work shows that adolescents are also protected from the aversive effects of many abusable drugs as measured by conditioned taste avoidance (CTA). However, such effects of methylphenidate (MPH, widely prescribed to adolescents with ADHD) have not been characterized.
  
  
  OBJECTIVE
  The effect of age on MPH-induced CTA was assessed. In addition, MPH-induced changes in brain-derived neurotrophic factor (BDNF) activity in the insular cortex (IC) and central nucleus of the amygdala (CeA), known to be important to CTA, were examined and related to CTAs in adolescents and adults.
  
  
  METHODS
  CTAs induced by MPH (0, 10, 18, and 32 mg/kg) were assessed in adolescent (n = 34) and adult (n = 33) male Sprague Dawley rats. Following MPH CTA, IC and CeA tissue was probed for differences in BDNF and tropomyosin-related kinase receptor-B (TrkB) using Western blots.
  
  
  RESULTS
  Blunted expression of MPH CTA was observed in the adolescents versus adults, which correlated with generally attenuated adolescent BDNF/TrkB activity in the IC, but the drug effects ran contrary to the expression of CTA.
  
  
  CONCLUSIONS
  Adolescents are protected from the aversive effects of MPH versus adults, but further work is needed to characterize the possible involvement of BDNF/TrkB.
authors.affiliation: Psychopharmacology Laboratory, Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, USA, bradley.wetzell@american.edu.
authors.forename: B Bradley
authors.initials: BB
authors.lastname: Wetzell
authors.forename: Mirabella M
authors.initials: MM
authors.lastname: Muller
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Cobuzzi
authors.forename: Zachary E
authors.initials: ZE
authors.lastname: Hurwitz
authors.forename: Kathleen
authors.initials: K
authors.lastname: DeCicco-Skinner
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Riley
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D066274:Central Amygdaloid Nucleus / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects / Q000502:physiology; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology*; D010766:Phosphorylation; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000378:metabolism; D012439:Saccharin / Q000008:administration & dosage; D015398:Signal Transduction; D055697:Taste Perception / Q000187:drug effects* / Q000502:physiology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D018765:Dopamine Uptake Inhibitors; D008774:Methylphenidate; D020813:Receptor, trkB; D012439:Saccharin