An investigation of pharmacologic and behavioral tolerance to morphine in rats.
D000698:Analgesia; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004361:Drug Tolerance; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
D009020:Morphine