title: Daily susceptibility variations to the morphine-induced hyperactivity of rats.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D004780:Environment, Controlled; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats
chemical_list: D009020:Morphine