title: Persistence of morphine in central nervous system of rats after a singel injection and its bearing on tolerance.
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000032:analysis / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D004361:Drug Tolerance; D008722:Methods; D009020:Morphine / Q000008:administration & dosage* / Q000032:analysis / Q000378:metabolism; D011868:Radioisotopes; D051381:Rats; D011955:Receptors, Drug; D013997:Time Factors
chemical_list: D011868:Radioisotopes; D011955:Receptors, Drug; D009020:Morphine