Effects of scopolamine and physostigmine on acquisition of morphine-treated rats in Morris water maze performance

AIM: To investigate effects of morphine on acquisition process of rats and interactions of opioid and cholinergic systems by Morris water maze performance. METHODS: Morris water maze was used to measure the latency of ruts With drugs 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/kg 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 10 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. CONCLUSION: 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.