The effects of multiple injections of morphine sulfate on shuttle-box behavior in the rat.
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D004361:Drug Tolerance; D004924:Escape Reaction / Q000187:drug effects*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D009020:Morphine