Effects of scopolamine and physostigmine on acquisition of morphine-treated rats in Morris water maze performance.
OBJECTIVE
To investigate effects of morphine on acquisition process of rats a nd interactions of opioid and cholinergic systems by Morris water maze performance.


METHODS
Morris water maze was used to measure the latency of rats with drug s treatment to find the covert platform.


RESULTS
Chronic morphine administration (10 mg/kg) impaired the acquisition process of rats in Morris water maze task. Appreciable difference was identified with morphine 10 mg/k g group compared with morphine 3 mg/kg group. Co-administration of morphine (10 mg/kg) and scopolamine (3 mg/kg) aggravated acquisition impairment induced by morphine 1 0 mg/kg or scopolamine alone, though scopolamine itself induced no salient changes in acquisition capabilities of rats. In addition, physostigmine (0.1 mg/kg) could appreciably attenuate morphine-induced acquisition impairment.


CONCLUSIONS
Morphine 10 mg/kg evidently impaired acquisition process of rats. There was a close relationship between the acquisition capabilities of morphine-treated rats and the functions of cholinergic system.
Zheng
Xi-Geng
XG
Brain and Behavior Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China. zxghf@ihw.com.cn
Li
Xin-Wang
XW
Yang
Xiao-Yan
XY
Sui
Nan
N
D000818:Animals; D018678:Cholinergic Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology; D010830:Physostigmine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012601:Scopolamine / Q000494:pharmacology*
D018678:Cholinergic Agents; D009294:Narcotics; D009020:Morphine; D010830:Physostigmine; D012601:Scopolamine