en Learning and Memory Neurophysiology/Pharmacology Experimental research article Experimental research article <div style="text-align: justify;"><strong>Introduction:</strong> Angiotensin converting enzyme (ACE) inhibitors are suggested to have some beneficial effects on the brain. In the present study the protective effects against brain tissues oxidative damage as possible mechanism for learning and memory improving effects of captopril was investigated in scopolamine treated rats.<strong> Methods:</strong> Fifty male Wistar rats were divided into seven groups and treated: saline as a control group, Sco (scopolamine) and Sco-Capto10, 50 and 100 (captopril 10, 50 and 100mg/kg before scopolamine). Treatment was passive avoidance test and then the cortical tissues were collected to measure malondialdehyde (MDA), nitric oxide (NO) metabolites, thiol, super oxide dismutase (SOD) and catalase (CAT). <strong>Results:</strong> Scopolamine decreased the latency to enter the dark in passive avoidance test compared to control group. It also increased MDA and NO metabolites while decreased thiol, SOD and CAT in comparison with control group. Captopril increased the latency to enter the dark. It also decreased MDA and NO metabolites while, increased thiol, SOD and CAT. <strong>Conclusion:</strong> Captopril protected brain tissues oxidative damage and improved learning and memory impairment induced by scopolamine.</div> Scopolamine, Captopril, Oxidative stress, Learning and memory. 91 100 http://ppj.phypha.ir/browse.php?a_code=A-10-994-2&slc_lang=en&sid=1 Hamid Reza Akbari 3200319475328460029568 3200319475328460029568 No Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Farimah Beheshti beheshtif931@mums.ac.ir 3200319475328460029569 3200319475328460029569 Yes Neuroscience Research Center, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran Hamid Reza Sadeghnia Sadeghniahr@mums.ac.ir 3200319475328460029570 3200319475328460029570 No Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran Soleyman Bafadam 3200319475328460029571 3200319475328460029571 No Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Yousef Baghcheghi Baghchey911@mums.ac.ir 3200319475328460029572 3200319475328460029572 No Student Research Committee, Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Mahmoud Hosseini hosseinim@mumsa.c.ir 3200319475328460029573 3200319475328460029573 No Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran