A Histological Study on the Effect of Different Methods of Mobile Phone Exposure on the Hippocampus in Adult Male Albino Rat

Abstract Introduction Using mobile phones has dramatically increased in the last few years. Mobile phones are carried mainly near the head during talking. Electromagnetic fields (EMF) emitted from cell phones may exert detrimental effects on human organs especially hippocampus which is an important organ concerned with memory and cognitive function. Aim To study the effect of different methods of mobile phone EMF exposure on the structure of hippocampus in adult male rats. Materials and Methods 28 adult male albino Wistar rats were equally divided into four groups: Group I (Control): were left without any interference. Group II (silent non-vibrating): exposed to continuous 900-1800 megahertz cell phone- emitted EMF for 60 minutes/day, for four weeks. Mobile phones were kept in silent, non-vibrating mode. Group III (silent vibrating): exposed to EMF as in group II, but with mobile phones kept in vibrating mode. Group IV (ringing non- vibrating): exposed to EMF as in group II, but with ringtone turned on and adjusted at 80 decibels. After four weeks of exposure, hippocampi were harvested form all rats. They were subjected to hematoxylin and eosin, toluidine blue, Caspase-3, and glial fibrillary acidic protein (GFAP) immunohistochemical stain as well as transmission electron microscopic examination. Morphometric and statistical studies were also done. Results pyramidal cells in CA3 area of Group IV (ringing non-vibrating) showed condensed chromatin clumps, distorted mitochondria, and clumped neurofilaments. A significant decrease in the mean thickness of the pyramidal cell layer of the CA3 area was noticed compared to other groups. While a significant increase in the mean number of degenerated pyramidal cells, number of caspase-3 positive cells as well as number of astrocytes was noticed in CA3 area of group IV compared to other groups. A significant increase in the mean optical density of caspase-3 and GFAP was also noticed in CA3 of group IV compared to other groups. Conclusions Exposure to EMF caused significant changes in the structure of hippocampus especially CA3 area. There was no significant difference between silent and vibrating mode. The worst changes were detected in ringing mode.