Striatal cholinergic activity during morphine-induced catalepsy in the rat: development of tolerance.
Morphine hydrochloride (10 mg/kg,i.p.) induced marked catalepsy in rats, which was associated with significantly enhanced striatal acetylcholine levels and reduced cholinesterase activity. Rapid tolerance to morphine-induced catalepsy was noted after twice daily administrations, the tolerance being discernible after the third injection and was complete after the eleventh injection. With the development of tolerance, morphine-induced effects on striatal acetylcholine and cholinesterase were progressively reversed, confirming striatal cholinergic involvement in morphine-induced catalepsy in the rat.
D000109:Acetylcholine / Q000032:analysis*; D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D002375:Catalepsy / Q000139:chemically induced* / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D008297:Male; D009020:Morphine; D051381:Rats
D009020:Morphine; D000110:Acetylcholinesterase; D000109:Acetylcholine