Volume 8, Issue 1 (Spring 2006)                   Advances in Cognitive Sciences 2006, 8(1): 1-8 | Back to browse issues page

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1- University of Tehran, Faculty of Medicine, Department of Pharmacology, Research Center for Cognitive Sciences.
Abstract:   (1272 Views)
Objective: Experimental studies on animals show that nicotine agonists have a significant effect on the enhancement of attention and memory. However, opioid agonists have an impairing effect on memory and the pre-training administration of these drugs decreases the memory. In the present study, the effects of nicotine pretreatment on state-dependent learning by morphine and its interaction with dopamine and cholinergic receptors in mice were investigated. 
Method: This was an experimental study that was carried out on mice. To study and assess the animals’ memory, the step down latency from a platform was measured in a passive avoidance task. 
Results: Pre-training administration of morphine led to memory impairment. This amnesia was not observed in mice that had received nicotine on the day of the test and nicotine-pretreated mice (mice that had received different doses of nicotine for three successive days followed by 14 days of no drug treatment). Daily injection of atropine 10 minutes prior to the injection of nicotine for three successive days prevented morphine-induced amnesia, whereas the injection of dopamine receptor antagonists did not have the same effect as atropine

Conclusion: nicotine pretreatment affects memory through the cholinergic system and not through the dopaminergic system.
Full-Text [PDF 211 kb]   (246 Downloads)    
Type of Study: Research | Subject: Special
Received: 2005/10/24 | Accepted: 2005/12/22 | Published: 2006/03/21