Investigation Of The Impact Of 900 MHz Microwave Radiation To The Emotion,Memory And Gut Microbiome Of Mice

In this paper,the electromagnetism reverberation chamber has used to be simulate the frequency effects of 900 MHz microwave radiation in mobile phone on the emotional behavior,learning memory and gut microbiome of different strains of mice,clear the sensitivity and biological effects of each strain of mice during this frequency microwave radiation.First,to obtain a stable,continuous,and effective 900 MHz microwave,before the start of the experiment,the basic equipment,main equipment,and agitator in the electromagnetic reverberation chamber were been checked.It was set four different gear positions of the stabilized power supply.Under the condition of the radiation parameters of the fixed frequency and the absolute value of the power,the test of field strength distribution was been performed on the effective working area of the electromagnetic reverberation chamber.Measured by grid method,place the microwave detection probe directly above the grid detection point,record field strength from top to bottom and left to right,take the average and standard deviation of the field strength of the detection point,calculate the coefficient of variation of the field strength stability of the detection point.It used to be characterize the stability of the field strength at the detection point.The result shows that the gear position of the DC stabilized power supply increasing,the speed of the reverberation chamber agitator increasing.The field strength of the reverberation chamber was gradually increasing,but it was not statistically different in four different gears between field strength and coefficient of variation.This result showed that the uniform distribution of field strength in the effective working area of the electromagnetic reverberation chamber equipment is better.The state of the reverberation chamber is generally stable.The fluctuations of the field strength in the effective working area under the four stirred up conditions according to the four different gear position are generally stable.Explain that the device has good reliability gear for electromagnetic radiation damage effect and medical protection research.It illustrated that the equipment has good reliability in the research of electromagnetic radiation damage effect and medical protection.Subsequently,the electromagnetic reverberation chamber was use to be the microwave radiation source term,conduct animal experiments study in its effective work areas.The method was to divide BALB/c,C57 and ICR selected strains of mice into the microwave radiation group and the control group.The mice of the radiation groups have exposed to microwaves of 900 MHz frequency,the absolute power of-27 dBm and a Specific Absorption Ratio(SAR)value of 0.495 W/kg in an electromagnetic reverberation chamber for four hours per day and 42 days in total.The control groups have kept in the same conditions as the radiation groups except that they have not exposed to microwaves.After the end of radiation,the elevated plus maze test,forced-swimming test,tail suspension test and open-field test of the radiation group and the control group in each strains of mice has conducted.After the end of the behavioral experiment,take the mice blood from the eye socket,serum has collected by centrifugation after stationary at room temperature,detection of cortisol(CORT)and epinephrine(EPI)in serum of mice.Compared with control mice of the correspondent control groups,the results of the elevated plus maze test showed that the microwave radiation exerted no obvious effect on the anxiety behaviors of C57 and ICR mice;the results of the open-field test the radiation group ICR mice was produced anxiety-like behavior.The results of Tail-suspended test and Forced-swimming test showed that the BALB/c and C57 mice in radiated groups were produced depression-like behaviors in comparison with their correspondent control groups.The results of CORT and EPI in serum of mice showed that the radiation group C57 mice producted depression-like behavior.In a word,at the same radiation frequency,radiation dose and time,the sensitivity of mice to 900 MHz microwave radiation closely related to their strain.Acorrding to the same conditions of the microwave radiation,different strains of mice showed different results in the emotional behavior experiment.Under the 900 MHz microwave radiation,delecting and using C57 and ICR strains with significant differences in emotional behavioral damage in mice which to further explore the effects of microwave radiation on learning and memory in mice.The method was to divide C57 and ICR selected strains of mice into the microwave radiation group and the control group.The mice of the radiation groups have exposed to microwaves of 900 MHz frequency,the absolute power of-27 dBm and a Specific Absorption Ratio(SAR)value of 0.495 W/kg in an electromagnetic reverberation chamber for four hours per day and 52 days in total.The mice in each group were exposed to radiation for 18-23 days to morris water maze positioning navigation training experiment,and the space exploration experiment based on water maze was carried out on 24,38 and 52 days.After the end of morris water maze experiment,execution of mice by neck amputation,immediate removal the hippocampi tissue from mouse brain.The content of brain-derived neurotrophic factor(BDNF)in hippocampi of mice has detected by Western blotting.Compared with control mice of the correspondent control groups,the results of the 5 days of positioning navigation training experiment showed that the there was no significant difference in latency and total distance between C57 mice in radiation group,but with the prolongation of training time,the two indexes showed a downward trend.There was no significant difference in the latency of ICR mice in radiation group,and the total distance and latency decreased with the extension of training time.The results of space exploration experiments showed that there was no significant difference in the percentage of total swimming distance between the C57 and ICR mice in the radiation quadrant and the total swimming time in the platform quadrant compared with the control group.The results of Western blotting test showed that radition group C57 and ICR mice the BDNF content hippocampi tissue significantly decreased compared with the control group.Thus,it can be seen,although the microwave radiation with a SAR value of 0.495 W/kg lasted for 900 MHz did not affect the learning and memory ability of the mice in each strain,the BDNF content in the hippocampi tissue of the radiation mice decreased significantly,suggested that the mice may have received certain degree of radiation damage.In view of the large amount of literature in recent years,in addition to the host itself,the intestinal flora may also play a role in the response and reaction of the host in different environmental factors.Therefore,in order to proceed from another perspective besides the host to evaluate the effect of 900 MHz microwave radiation on mice,we performed 16 S ribosomal DNA(16S rDNA)sequencing analysis on the fecal samples of each group to study changes of gut microflora microecosystem after microwave radiation in mice.The methods are that DNA extraction and 16 S rDNA sequencing have performed at three time points: before radiation,at 7 days and 21 days of radiation.The results showed that 900 MHz microwave radiation had no significant effect on the species diversity and flora richness of intestinal flora in mice,but there was a certain degree of change at the level of phylum and order.Specifically,at the Phylum level,Firmicutes and Bacteroidetes were the dominant flora phylum of each group mice gut microflora,at the corresponding time points,the relative abundance of Bacteroidales in BALB/c mice exposed to continuous radiation for 21 days was significantly higher than that in control group(P<0.05).At the Order level,Clostridiales,Bacteroidales and Lactobacillales were the dominant flora order of each group mice gut microflora,at the corresponding time points,compared with the control group,the relative abundance of Clostridiales in BALB/c mice exposed to continuous radiation for 21 days was significant decline(P<0.05),the relative abundance of Bacteroidales significant increase(P<0.05).At the Genus level,Alistipes,Bacteroides,Lachnospiraceae_NK4A13 6_group,Ruminococcaceae_UCG-014,Lactobacillus were the dominant flora genus of each group mice gut microflora,at the corresponding time points,compared with the control group,there was a statistical difference in Bacteroidales of BALB/c mice,Ruminococcaceae_UCG-014 of ICR mice,Lactobacillus,Alistipes and Ruminococcaceae_UCG-014 of C57 mice that were continue radiation for 21 days(P<0.05).Beside,at the three classification levels of Phylum/ Order and Genus,the relative abundance of bacteria in the radiation group was different from that in the control group on the time axis,which has related to age,individual difference and experimental operation of mice,but not to microwave radiation.The results of principal component analysis(PCA)and principal coordinate analysis(PCoA)showed that microwave radiation had no significant effect on the microbial community and species composition of intestinal flora in mice.Thus it can be seen,at the t level of Phylum,Order and Genus,the microwave radiation had certain effect on the relative abundance of gut microbiome in mice,and showed the sensitivity difference of different strains.However,the irradiation condition had no effect on the overall composition and structure of gut microbiome in mice,and had no significant effect on gut microbiome in mice.In summary,the electromagnetic reverberation chamber equipment has good reliability in the research of electromagnetic radiation damage effect and medical protection.At the same radiation frequency,radiation dose and time,the sensitivity of mice to microwave radiation closely related to their strains,suggesting that BALB/c and C57 mice could used to study the mechanism of depression-like behavior related to electromagnetic radiation,and ICR mice has used to study the mechanism of anxiety-like behavior.Furthermore,the microwave radiation of this condition only has a certain effect on the relative abundance of certain bacteria,but it has no effect on the overall composition of the gut microbiome of mice,and generally has no significant effect on the gut microbiome of mice.It indicated that the effect of microwave radiation on the depression and anxiety-like behavior of mice not be directly related to changes in gut microbiome,but mainly in response to the electromagnetic radiation of the host(mice)itself.