en Behavioral Neuroscience Behavioral Neuroscience Original Original <div style="text-align: justify;"><strong>Introduction</strong>: We investigated the sexually dimorphic effects of Dextromethorphan (DM) on cognitive and depression-like behaviors as well as on hippocampal histology in rats following acute administration.<br> <strong>Methods</strong>: Wistar rats of both sexes were treated with 25 or 50 mg/kg of DM for 7 days via intraperitoneal injection. At the end of the administration, behavioral studies were performed on the Tail Suspension Test (TST) for depressive-like behaviors and the Y-maze for cognitive behaviors. The rats&rsquo; brains were excised and processed for routine histological analysis.&nbsp;<br> <strong>Results</strong>: Our results showed that DM significantly increased (P<0.05) immobility time in the TST in male rats but not female ones, and decreased percentage alternation (P<0.001) on the Y-maze in both male and female rats. Histological analysis revealed no morphological changes in the hippocampus following DM treatment.&nbsp;<br> <strong>Conclusion</strong>: DM impairs cognitive functions in both male and female rats without histologic defects in the hippocampus. However, the induced depressive-like behaviors following DM administration may be sexually dependent.</div> Dextromethorphan, Depression, Cognition, Hippocampus, Female, Male 393 400 http://bcn.iums.ac.ir/browse.php?a_code=A-10-1389-1&slc_lang=en&sid=1 Omamuyovwi Meashack Ijomone ijomoneom@futa.edu.ng 13700319475328460021111 13700319475328460021111 Yes Department of Anatomical Sciences, School of Health and Health Technology, Federal University of Technology Akure, Nigeria.; Department of Anatomy and Forensic Anthropology, Faculty of Basic Medical Sciences, Cross River University of Technology, Calabar, Nigeria. Ifechukwude Joachim Biose ifybio@gmail.com 13700319475328460021112 13700319475328460021112 No Department of Anatomy and Forensic Anthropology, Faculty of Basic Medical Sciences, Cross River University of Technology, Calabar, Nigeria.