Effects Of 1800MHz Electromagnetic Radiation On Hippocampus Neural Cell Of Mice With Different Development Degree

1 Background and purpose Along with the rapid development of electronic technology and communication industry,many kinds of electronic equipment,wireless communication facilities are widely used in daily life and work.The increasing electromagnetic radiation in the environment,following the air pollution,water pollution,noise pollution become the 4th environment pollution.The developing children are also inevitable exposure to different frequency and intensity electromagnetic radiation.There are more and more researches about the influence of electromagnetic radiation on the the central nervous system function.But the research about electromagnetic radiation effects on the brain is focuses on the impact on the mature brain tissue,It was found that mobile phone electromagnetic radiation can lead to some insult about the adult mice nervous system,such as the increase of blood-brainbarrier(BBB)permeability,neurotransmitter metabolic disorder,cortex and hippocampus in histology and ultrastructure damage,which including loss of neurons,disordered arrangement of cells,the nissl substance lost,appear transparent area in the nuclear,a series of early apoptosis signs.But the research about immature brain is less.Studies have shown that the body’s tissues are particularly sensitive to the effects of electromagnetic fields in puberty.And the immature brain is most vulnerable,such as the ability to disrupt memory,learn and neurobehavioral,become one of the focuses of the home and abroad researches.Because of the complexity of damage mechanism of neurobiology caused by electromagnetic radiation,so whether the effects of electromagnetic eadiation on the brain of mice with different development degree is different,there is not clear conclusion.This research selects postnatal 7-day old(P7)and 21-day old(P21)Kunming mice,because their stages of brain development correspond to neonatal and juvenile human brains.Through simulation 1800 MHZ electromagnetic radiation exposure environment caused by mobile phone.To study the effects of short-term electromagnetic radiation on hippocampus neural cell proliferation of mice with different ages.For the purpose of prevention and control puberty brain damage caused by electromagnetic radiation provide theoretical basis.2 Materials and methods The postnatal 7-day old(P7)and 21-day old(P21)Kunming mice of both sexes were randomly divided into the exposure group(P7 and P21)or the control group(P7 and P21)(n = 12/group,which included 6 males and 6 females).The exposure group analog mobile phone radiation environment through the GTEM Cell chamber(1800MHz 1800 MHZ,28 v/m,2.0m W/cm2),for 8 hours daily Interval of 1h for 3 consecutive days.Brd U was injected intraperitoneally 1 hour before each exposure session,the control group were given the same treatment virtual pseudo radiation,and given the same volumee saline solution by intraperitoneal injection.All animals were sacrificed 24 hours after the last exposure.The mice inhalation anesthesia with anhydrous ether first,Then perfusion saline and formaldehyde solution to body until pale and harden,Separation and take out the the brain tissue rapidly,Preparation of the hippocampus tissue slices,detected the numbers of cells that were positive for active caspase-3,Brd U,Ki67,BLBP,and HH3 in the subgranular zone of the dentate gyrus by immunohistochemistry.3 Results 3.1 The effects of electromagnetic radiation on active Caspase-3 cell expression in the hippocampus dentate gyrus subgranular zone of the mice with different development degree Observed under 200 magnified visual field with optical microscopy: There is almost no active caspase-3 cell found in the subgranular zone of the dentate gyrus of P7 and P21 group.Compared with control group,Exposed group hippocampal dentate gyrus area structure is loose,nerve cell arranged loosely and disorde.3.2 The effects of electromagnetic radiation on active Brd U,Ki67 cell expression in the hippocampus dentate gyrus subgranular zone of the mice with different development degree Compared with control group,The number of Brd U,Ki67-positive cells of P7 exposure group in the subgra-nular zone of the dentate gyrus was significantly increased.The difference was statistically significant(P < 0.05);The number of Brd U,Ki67-positive cells of P21 exposure group in the subgra-nular zone of the dentate gyrus was almost no change compared with the control group.There was no statistically significant difference(P > 0.05).3.3 The effects of electromagnetic radiation on active BLBP,HH3 cell expression in the hippocampus dentate gyrus subgranular zone of the mice with different development degree Compared with control group,The number of Brd U and Ki67-positive cells of P7 exposure group in the subgra-nular zone of the dentate gyrus was significantly decreased.The difference was statistically significant(P < 0.05);The number of BLBP and HH3-positive cells of P21 exposure group in the subgra-nular zone of the dentate gyrus was almost no change compared with the control group.4 Conclusion The short-term exposure of mice with different developing degree brain to an 1800 MHz electromagnetic field had no influence on stem cell or neuronal cell death in the hippocampus.Cause the nerve cell proliferation in the immature brain,but no influence of the cell in the Hippocampal dentate gyrus in the mature brain.