title: [Effect of chronic morphine administration on the "reward" system in rats].
abstract: The influence of morphine on lateral hypothalamic self-stimulation in rats was studied, The drug was injected in stepwise increasing doses from 20 to 60 and 120 mg/kg per injection. A total of 30 injections were performed in 15 days. Initial doses of every new drug injection period exerted predominantly a suppressive action upon self-stimulation, while additional injections resulted in a stable and clearcut activation of the central mechanisms mediating "rewards".
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D004558:Electric Stimulation; D006801:Humans; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D012201:Reward; D012653:Self Stimulation / Q000187:drug effects; D019966:Substance-Related Disorders / Q000209:etiology
chemical_list: D009020:Morphine
vernacular_title: Vliianie khronicheskogo vvedeniia morfina na sistemu "nagrady" u krys.