The Effect of 835 MHz Radiofrequency Radiation Exposure on the Immunohistochemical Distribution of Calbindin D28k and Calretinin in the Mouse Cerebellar Cortex

Abstract

Widespread use of mobile phones and subsequent electromagnetic field (EMF) exposure have raised crucial question of their possible biological effects on the nervous system. The study on the effect of radiofrequency (RF) radiation on the nervous system, however, did not precede enough to determine the biological hazard to brain. Until now, several studies have reported decreases in neuron number and neuronal damage in the cortex, hippocampus, and basal ganglia in the brains of animals exposed to RF radiation. However, there were few reports about the cerebellum, the main voluntary motor control center. In this regard, by using immunohistochemisty, current study intended to investigate the changes in the calbindin D28k (CB) and calretinin (CR)-immunoreactivity (IR) in the mouse cerebellar cortex after EMF exposure at 835 ㎒ for different exposure times and absorption rates, 1h/day for 5 days at 1.6 W /㎏, 1 h/day for 5 days at 4.0 W /㎏, 5 h/day for 1 day at 1.6 W /㎏, 5 h/day for 1 day at 4.0 W /㎏, daily exposure for one month at 1.6 W /㎏. Among groups, most prominent CB IR was observed in the Purkinje cell layer followed by molecular and granular layer. The highest CB IR was noted in 5 h/day for 1 day at 1.6 W /㎏ in the entire three layers while the lowest was noted in one month at 1.6 W /㎏. Similarly CR IR was maximum in one month at 1.6 W /㎏ whilst the lowest was observed in 1 h/day for 5 days at 4.0W/㎏. EMF exposure for 5 days at 1.6 W/㎏ reduced CB-IR. The CR-IR was mainly localized in small cells in the granular layer, with maximum IR observed after one month exposure. Therefore, the present study suggest the possibility of alterations of calcium ion concentration, which playa role in maintaining metabolic homeostasis, in the cerebellum after long-term exposure to 835 ㎒ of RF radiation, which might lead to the disruption of normal trait.