%0 Journal Article %A Malek mohammadi, Nazanin %A Khalilzadeh, Azita %A Fazli Tabaei, Soheila %A Zarindast, Mohammadreza %T Influence of Morphine- or Apomorphine-Induced Sensitization on Histamine State-Dependent %J Advances in Cognitive Sciences %V 8 %N 3 %U http://icssjournal.ir/article-1-202-en.html %R %D 2006 %K Apomorphine, Morphine, Histamine, Memory, %X Objective: To survey the interaction of morphine and histamine and the involvement of dopaminergic system on histamine state-dependent learning in step-down passive avoidance test. Method: First, with the administration of 3 different doses of morphine for three days and a subsequent five days of no drug treatment, mice were sensitized to morphine. Then, the necessary memory tests were carried out and the effect of histamine on the memories of morphine-sensitized mice and non-sensitized mice was compared. Step-down passive avoidance test was used to assess memory. Results: Sensitization with morphine and apomorphine prevented histamine-induced memory impairment and memory was retrieved. However, the co-administration of apomorphine and sulpride as a D2 receptor antagonist decreased the effect of memory retrieval; but the administration of SCH 23390 as a dopamine 1 receptor antagonist had no such effect. Also, the co-administration of naloxone, SCH 23390, and sulpride, plus morphine significantly decreased the effect of memory retrieval. Conclusion: Apomorphine activates the histaminergic neural system through stimulation of D2 receptors and the improvement of memory in morphine sensitized mice through the stimulation of opioid and D1 and D2 receptors. %> http://icssjournal.ir/article-1-202-en.pdf %P 1-10 %& 1 %! %9 Research %L A-10-2-181 %+ Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, National Center for Addiction Studies, Tehran, Iran. %G eng %@ 1561-4174 %[ 2006