title: Pre-exposure to cocaine or morphine attenuates taste avoidance conditioning in adolescent rats: Drug specificity in the US pre-exposure effect.
abstract: Although the attenuating effects of drug history on conditioned taste avoidance (CTA) learning have been widely investigated in adults, such effects in adolescents have not been well characterized. Recent research has suggested that the display of the drug pre-exposure effect during adolescence may be drug dependent given that pre-exposure to ethanol attenuates subsequent conditioning, whereas pre-exposure to the classic emetic lithium chloride (LiCl) fails to do so. The present study began investigating the possible drug-dependent nature of the effects of drug pre-exposure by pre-exposing and conditioning adolescent male Sprague-Dawley rats to drugs from two additional classes, specifically psychostimulants (cocaine; Experiment 1) and opioids (morphine; Experiment 2). Consistent with prior work with ethanol (but not LiCl), prior exposure to both cocaine and morphine attenuated taste avoidance induced by these compounds. Although this work supports the view of drug-dependent pre-exposure effects on taste avoidance learning during adolescence, research is needed to assess its mechanisms.
authors.affiliation: Psychopharmacology Laboratory, Center for Behavioral Neuroscience, American University, Washington DC.
authors.forename: Matthew M
authors.identifier: 0000-0001-7137-6492
authors.initials: MM
authors.lastname: Clasen
authors.affiliation: Psychopharmacology Laboratory, Center for Behavioral Neuroscience, American University, Washington DC.
authors.forename: Briana J
authors.initials: BJ
authors.lastname: Hempel
authors.affiliation: Psychopharmacology Laboratory, Center for Behavioral Neuroscience, American University, Washington DC.
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Riley
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D011619:Psychotropic Drugs / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D011619:Psychotropic Drugs; D009020:Morphine; D003042:Cocaine
keywords: US pre-exposure; adolescence; cocaine; conditioned taste avoidance; drug dependency; morphine