fa نقش گیرنده‌های D1/D2 دوپامینی در فراموشی القا شده با 1ـ متیل ـ بتا ـ کربولین (هارمان) بر روی حافظه‌ی اجتنابی مهاری با استفاده از مدل Step-Down مقاله پژوهشی Original Research Article <p>Background and Objective: A number of &beta;-carboline alkaloids such as harmane are naturally present in the human food chain. In the present study the involvement of dopaminergic system on harmane induced-amnesia was investigated. Materials and Methods: One-trial step-down paradigm was used for the assessment of memory retention in adult male NMRI mice. Results: Intraperitoneal (i.p.) administration of harmane (5 and 10 mg/kg) immediately after training, dose-dependently decreased memory formation. Administration of D1/D2 receptors agonist, apomorphine (0.5 and 1 mg/kg, i.p.) before testing by itself could not alter memory retrieval. On the other hand, in the animals in which memory formation was impaired due to harmane post-training administration, pre-test administration of apomorphine (0.5 and 1 mg/kg, i.p.) 24 hr after training in day&rsquo;s test restored memory. Furthermore, administration of SCH23390 (0.025, 0.05 and 0.1 mg/kg, i.p.) or sulpiride (12.5, 25 and 50 mg/kg, i.p.) before testing by itself could not alter memory retrieval, respectively. On the other hand in the animals in which memory formation was impaired due to harmane post-training injection, pre-test administration of SCH23390 (0.05 and 0.1 mg/kg) or sulpiride (25, 50 mg/kg, i.p.) 24 hr after training in day&rsquo;s test decreased hamane-induced amnesia. Conclusion: These findings indicat the involvement of D1/D2 receptors in harmane induced-amnesia through different mechanism(s).</p> Keywords: Harmane, Apomorphine, SCH23390, Sulpiride, Step-down passive avoidance task, Mice 1 12 http://journal.zums.ac.ir/browse.php?a_code=A-10-4-541&slc_lang=fa&sid=1 Mohammad Nasehi محمد ناصحی mo58na@yahoo.com 5200319475328460060253 5200319475328460060253 Yes Islamic Azad University, Garmsar Branch, Semnan, Iran Morteza Piri مرتضی پیری 5200319475328460060254 5200319475328460060254 No Islamic Azad University, Ardabil Branch, Ardabil, Iran Maryam sadat Shahin مریم السادات شاهین 5200319475328460060255 5200319475328460060255 No Islamic Azad University- Shahr-e-rey Branch, Tehran, Iran Mohammad Reza Zarrindast محمدرضا زرین دست 5200319475328460060256 5200319475328460060256 No Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran