Effects Of Acute Exposure To 3500MHz Electromagnetic Radiation On The Auditory Cortex And Anxiety-like Behavior Of Guinea Pigs

Objective: Accumulating evidences have shown that electromagnetic radiation(EMR)may negatively affect human health.However,whether EMR affects the auditory system still unclear.The aim of present study is to detect the effect of 3500 MHz EMR on the auditory cortex(ACx)and anxiety-like behavior of guinea pigs.Methods: Guinea pigs were randomly divided into four groups,and exposed to 3500 MHz EMR at an average specific absorption rate(SAR)of0,2,4,10 w/kg respectively for 72 hours.After exposure,animal behaviors were observed by open field test(OFT),hearing thresholds were recorded by auditory brainstem response(ABR),the content of malonaldehyde(MDA),the activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)were detected by biochemical estimation,cell ultrastructure were observed by transmission electron microscope(TEM),cytochrome-c(Cyt c)and caspase-9 were evaluated by immunofluorescence(IF).Results: The hearing thresholds and basic indexes of animal behavior did not change significantly after exposure(P>0.05).However,MDA levels were increased(P<0.05),and SOD,GSH-px activities were decreased(P<0.05)in the exposure groups compared to the sham group.Ultrastructural changes,including swollen mitochondria and layered myelin sheaths,were observed.Cyt c relocalization and caspase-9activation were detected in the exposure groups.Conclusions: Oxidative stress is an important mechanism underlying the biological effects of EMR,which can induce ultrastructural damage to the ACx and cell apoptosis through a mitochondria-dependent mechanism.Moreover,oxidative stress,apoptosis induction and ultrastructural damage increase with the intensity of SAR in a dose-dependent manner.However,3500 MHz EMR does not increase hearing thresholds or induce anxiety.Further investigation is needed to explore the cumulative effect of mobile phone radiation on auditory system.