Delayed extinction and stronger reinstatement of cocaine conditioned place preference in adolescent rats, compared to adults.
Adolescence is a transitional period during development that is associated with a greater likelihood of addiction to drugs than any other age. One possibility for this observation is that learned associations between the rewarding experience of drugs and drug-related cues may produce greater motivational salience, and thus are more difficult to extinguish. Using an unbiased place-conditioning paradigm with two doses of cocaine (10 mg/kg or 20 mg/kg), the authors show here that adolescents require 75 +/- 17% more extinction trials than adults to extinguish cocaine place-preferences. Furthermore, once extinguished, adolescents display a greater preference for a previously cocaine-paired environment upon drug-primed reinstatement compared with adults. These results suggest that adolescent vulnerability to addiction involves robust memories for drug-associated cues that are difficult to extinguish. Therefore, drug-addicted adolescents may have a higher risk of relapse than adults, leading to greater prevalence of addiction in this population.
Brenhouse
Heather C
HC
McLean Hospital, Harvard Medical School, Belmont, MA 02144, USA. hbrenhouse@mclean.harvard.edu
Andersen
Susan L
SL
D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D001245:Association Learning / Q000187:drug effects*; D016739:Behavior, Addictive / Q000139:chemically induced; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004777:Environment; D005108:Extinction, Psychological / Q000187:drug effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D018765:Dopamine Uptake Inhibitors; D003042:Cocaine