title: Ontogenetic determinants of behavioral responses to morphine in rats.
abstract: Male Sprague-Dawley rats ranging in age from 20 to 110 days were injected with two doses of morphine sulphate, and examined for behavioral activation and catalepsy. Behavioral activation increased with age, while sensitivity to catalepsy declined. Ontogenetic and pharmacological responses suggest possible separate mediation of activation and catalepsy.
mesh_terms: D000367:Age Factors; D000375:Aging; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002375:Catalepsy / Q000139:chemically induced; D006801:Humans; D008297:Male; D008954:Models, Biological; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects
chemical_list: D011957:Receptors, Opioid; D009020:Morphine