Zarrindast Mohammad-Reza, Farahmandfar Maryam, Rostami Parvin, Rezayof Ameneh
Department of Pharmacology, Tehran University of Medical Sciences, Tehran, Iran.
J Psychopharmacol. 2006 Jan;20(1):59-66. doi: 10.1177/0269881105057003. Epub 2005 Sep 20.
In the present study, effects of intracerebroventricular (i.c.v.) injections of dopaminergic and cholinergic agents on morphine-induced amnesia in morphine-sensitized mice were investigated by using a one-trial passive avoidance task. Amnesia induced by pre-training morphine was significantly reversed in morphine-sensitized mice, which had previously received once daily injections of morphine (20 and 30 mg/kg, s.c.) for 3 days. Three daily injections of SKF 38393 (1, 2 and 4 g/mouse, i.c.v.) or SCH 23390 (0.25, 0.5, 0.75 and 1 g/mouse, i.c.v.) before morphine, and during morphine-sensitization, decreased and increased the amnesia induced by pre-training morphine respectively. Three daily injections of quinpirole (0.3, 1 and 3 g/mouse, i.c.v.) or sulpiride (0.03, 0.1, 0.3 and 1 g/mouse, i.c.v.) before morphine, also decreased and increased the amnesia induced by pre-training morphine respectively. Morphine-sensitized mice received similar injections of cholinergic agents. Three daily injections of physostigmine (1, 3 and 5 g/mouse, i.c.v.) or atropine (1, 4 and 7 g/mouse, i.c.v.) before morphine, and during morphine-sensitization, decreased and increased the amnesia induced by pre-training morphine respectively. Three daily injections of nicotine (0.75, 1 and 2 g/mouse, i.c.v.) or mecamylamine (1, 3 and 6 g/mouse, i.c.v.) before morphine, also decreased and increased the amnesia induced by pre-training morphine respectively. The results suggest that morphine sensitization affects the impairment of memory formation and thus it is postulated that central dopaminergic and cholinergic systems may play an important role in this effect.
在本研究中，通过单次被动回避任务，研究了脑室内注射多巴胺能和胆碱能药物对吗啡致敏小鼠吗啡诱导失忆的影响。预先接受吗啡训练诱导的失忆在吗啡致敏小鼠中显著逆转，这些小鼠此前每天皮下注射一次吗啡（20和30mg/kg），共3天。在吗啡注射前及吗啡致敏期间，每天脑室内注射三次SKF 38393（1、2和4μg/小鼠）或SCH 23390（0.25、0.5、0.75和lμg/小鼠），分别降低和增加了预先接受吗啡训练诱导的失忆。在吗啡注射前，每天脑室内注射三次喹吡罗（0.3、1和3μg/小鼠）或舒必利（0.03、0.1、0.3和1μg/小鼠），也分别降低和增加了预先接受吗啡训练诱导的失忆。吗啡致敏小鼠接受了类似的胆碱能药物注射。在吗啡注射前及吗啡致敏期间，每天脑室内注射三次毒扁豆碱（1、3和5μg/小鼠）或阿托品（1、4和7μg/小鼠），分别降低和增加了预先接受吗啡训练诱导的失忆。在吗啡注射前，每天脑室内注射三次尼古丁（0.75、1和2μg/小鼠）或美加明（1、3和6μg/小鼠），也分别降低和增加了预先接受吗啡训练诱导的失忆。结果表明，吗啡致敏影响记忆形成的损伤，因此推测中枢多巴胺能和胆碱能系统可能在这一效应中起重要作用。
