en Anatomical Sciences Anatomical Sciences Original Research Original Research <p><strong>Background: </strong>3,4- methylenedioxymethamphetamine (MDMA) is a chemical derivative of amphetamine that can induce learning and memory impairment. Due to&nbsp; the effect of neurotrophins&nbsp; on memory and learning, the impact of MDMA was evaluated&nbsp; on the brain - derived neurotrophic factor (BDNF), neurotrophin- 4 (NT-4), and tropomyosin- related kinase B (Trk- &beta;) expression in the hippocampus.<br> <strong>&nbsp;&nbsp; Methods:</strong> In this study, 20 adult male Wistar rats (200-250 g) received saline (1 mL) or 10 mg/kg of MDMA intraperitoneally as single or multiple injection for 2 consecutive days per week for 2 months. Expression of BDNF, Trk-&beta;, and NT4 were assessed using Western blotting and RT PCR methods.&nbsp;<br> <strong>&nbsp;&nbsp; Results:</strong> Our results revealed that the expression of BDNF, Trk- &beta;, and NT4 proteins and genes significantly decreased in MDMA groups compared to the sham group (p<0.05). Furthermore, the acute group showed the lowest expression of these proteins.<br> <strong>&nbsp;&nbsp; Conclusion:</strong> The results of the present study suggest that ecstasy administration may downregulate the expression of BDNF, Trk- &beta;, and NT-4 in hippocampus, which is more extensive in case of acute treatment. It seems that in the chronic group, hippocampus was able to compensate the ecstasy- induced neurotoxicity.&nbsp;<br> &nbsp;<br> &nbsp;</p> Ecstasy, BDNF, Trk- β, NT4 344 348 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1194-1&slc_lang=en&sid=1 Sara Soleimani Asl s.soleimaniasl@umsha.ac.ir 200319475328460034008 200319475328460034008 No Research Center for Behavioral Disorders and Substance Abuse, Hamadan University of Medical Sciences, Hamadan, Iran & Anatomy Department, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran. Mohamad Bakhtiar Hesam Shariati bakh_sh@yahoo.com 200319475328460034009 200319475328460034009 No Research Center for Behavioral Disorders and Substance Abuse, Hamadan University of Medical Sciences, Hamadan, Iran. Mehdi Medizadeh maranaoo2004@yahoo.com 200319475328460034010 200319475328460034010 No Cellular & Molecular Research Center, Faculty of Advanced Technology in Medicine, Department of Anatomical Sciences, Iran University of Medical Sciences, Tehran, Iran. Mohammad Ahmadpanah ahmadpanah@umsha.ac.ir 200319475328460034011 200319475328460034011 No Research Center for Behavioral Disorders and Substance Abuse, Hamadan University of Medical Sciences, Hamadan, Iran. Maryam Sohrabi sohrabi3@yahoo.com 200319475328460034012 200319475328460034012 Yes Anatomy Department, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.