TY - JOUR T1 - The Effect of Extremely Low Frequency Electromagnetic Fields on Visual Learning, Memory and Anatomical Structures of the Brain in Male Rhesus Monkeys TT - بررسی اثر میدان‌های الکترومغناطیس با فرکانس بسیار پایین بر یادگیری و حافظه بینایی و ساختار آناتومیکی مغز در میمون‌های رزوس نر JF - ISMJ JO - ISMJ VL - 21 IS - 1 UR - http://ismj.bpums.ac.ir/article-1-913-en.html Y1 - 2018 SP - 40 EP - 53 KW - electromagnetic field KW - hippocampus KW - prefrontal area KW - macaca mulatta monkey KW - visual learning N2 - Background: Humans in modern societies are exposed to substantially elevated levels of electromagnetic field (EMF) emissions with different frequencies. The neurobiological effects of EMF have been the subject of debate and intensive research over the past few decades. Therefore, we evaluated the effects of EMF on visual learning and anatomical dimensions of the hippocampus and the prefrontal area (PFA) in male Rhesus monkeys. Materials and Methods: In this study, four rhesus monkeys of Macaca mulatta species were irradiated by 0.7 microtesla ELF-EMF either at 5 or 30 Hz, 4 h a day, for 30 days. Alterations in visual learning and memory were assessed before and after irradiation phase by using a box designed for challenging animals for gaining rewards. Furthermore, the monkeys’ brains were scanned by MRI technique one week before and one week after irradiation. The monkeys were anesthetized by intramuscular injection of ketamine hydrochloride (10–20 mg/kg) and xylazine (0.2–0.4 mg/kg), and scanned with a 3-Tesla Magnetom, in axial, sagittal, and coronal planes using T2 weighted protocol with a slice thickness of 3 mm. The anatomical changes of hippocampus and the prefrontal area (PFA) were measured by volumetric study. Results: Electromagnetic field exposure at a frequency of 30 Hz reduced the number of correct responses in the learning process and delayed memory formation in the two tested monkeys. Meanwhile, ELF-EMF at 5 Hz had no effect on the visual learning and memory changes. No anatomical changes were observed in the prefrontal area and the hippocampus at both frequencies. Conclusion: ELF-EMF irradiation at 30 Hz adversely affected visual learning and memory, probably through factors other than changes in brain structure and anatomy. M3 10.29252/ismj.21.1.40 ER -