Opioid-reinforced operant behavior: selective suppression by alpha-methyl-para-tyrosine.
Morphine-addicted rats performed operant responses for opioid or milk rewards. When rats were then denied access to opioids, abstinence symptoms developed. Responding under extinction conditions 2 wk. after opioid withdrawal provided a measure of the "relapse" tendency. Systemic administration of DL-alpha-methyl-para-tyrosine, an inhibitor of catecholamine synthesis, suppressed these responses if they had been reinforced by an opioid but not if they had been established with milk reinforcement. This indicates that the integrity of the catecholamine systems is vital for relapse to occur.
D000284:Administration, Oral; D000818:Animals; D001562:Benzimidazoles / Q000008:administration & dosage; D001593:Benzyl Compounds / Q000008:administration & dosage; D002395:Catecholamines / Q000037:antagonists & inhibitors; D003216:Conditioning, Operant / Q000187:drug effects*; D003864:Depression, Chemical; D004048:Diethylamines / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological; D006801:Humans; D007274:Injections, Intraperitoneal; D007536:Isomerism; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology*; D008892:Milk; D009020:Morphine / Q000008:administration & dosage; D009021:Morphine Dependence; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D012008:Recurrence; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology; D013375:Substance Withdrawal Syndrome / Q000209:etiology; D014443:Tyrosine / Q000008:administration & dosage; D014868:Water Deprivation
D001562:Benzimidazoles; D001593:Benzyl Compounds; D002395:Catecholamines; D004048:Diethylamines; D008781:Methyltyrosines; D014443:Tyrosine; D009020:Morphine