Relationship between Cognition Function and Hippocampus Structure after Long-term Microwave Exposure

Objective To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat.Methods Experiments were performed on 184 male Wistar rats（three exposure groups and a sham group）.Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5,5,and 10 mW/cm2.Learning and memory abilities were assessed by Morris water maze.High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus.Hippocampal structures were observed by histopathological analysis.Results Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d,14 d,and 1 m in all three microwave exposure groups.Neurotransmitter concentrations of four amino acids（glutamate,aspartic acid,glycine,and gamma-aminobutyric acid） in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group.There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups.Further,mitochondria became swollen and cristae were disordered.The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles.Conclusion These data suggest that the hippocampus can be injured by long-term microwave exposure,which might result in impairment of cognitive function due to neurotransmitter disruption.

Microwave Exposure Impairs Synaptic Plasticity in the Rat Hippocampus and PC12 Cells through Over-activation of the NMDA Receptor Signaling Pathway

Objective The aim of this study is to investigate whether microwave exposure would affect the N-methyI-D-aspartate receptor （NMDAR） signaling pathway to establish whether this plays a role in synaptic plasticity impairment. Methods 48 male Wistar rats were exposed to 30 mW/cm^2 microwave for 10 min every other day for three times. Hippocampal structure was observed through H＆E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm^2 microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated. Results Microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits （NR1, NR2A, and NR2B） and related signaling molecules （CaZ＋/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein） were examined. Conclusion 30 mW/cm^2 microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.

Behavioral Abnormality along with NMDAR-related CREB Suppression in Rat Hippocampus after Shortwave Exposure

Objective To estimate the detrimental effects of shortwave exposure on rat hippocampal structure and function and explore the underlying mechanisms. Methods One hundred Wistar rats were randomly divided into four groups(25 rats per group) and exposed to 27 MHz continuous shortwave at a power density of 5, 10, or 30 m W/cm^2 for 6 min once only or underwent sham exposure for the control. The spatial learning and memory, electroencephalogram(EEG), hippocampal structure and Nissl bodies were analysed. Furthermore, the expressions of N-methyl-D-aspartate receptor(NMDAR) subunits(NR1, NR2 A, and NR2 B), c AMP responsive element-binding protein(CREB) and phosphorylated CREB(p-CREB) in hippocampal tissue were analysed on 1, 7, and 14 days after exposure. Results The rats in the 10 and 30 m W/cm^2 groups had poor learning and memory, disrupted EEG oscillations, and injured hippocampal structures, including hippocampal neurons degeneration, mitochondria cavitation and blood capillaries swelling. The Nissl body content was also reduced in the exposure groups. Moreover, the hippocampal tissue in the 30 m W/cm^2 group had increased expressions of NR2 A and NR2 B and decreased levels of CREB and p-CREB. Conclusion Shortwave exposure(27 MHz, with an average power density of 10 and 30 m W/cm^2) impaired rats' spatial learning and memory and caused a series of dose-dependent pathophysiological changes. Moreover, NMDAR-related CREB pathway suppression might be involved in shortwave-induced structural and functional impairments in the rat hippocampus.

AduoLa Fuzhenglin Down-regulates Microwave-induced Expression of β_1-adrenergic Receptor and Muscarinic Type 2 Acetylcholine Receptor in Myocardial Cells of Rats

This paper is aimed to study the effect of ADL on expression of ~z-AR and Mz-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of ~I-AR and Mz-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/（kg.d） ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/（kg.d） ADL groups than in microwave group. So we have a conclusion that the expression of I^z-AR and Mz-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.

Real-time Microwave Exposure Induces Calcium Efflux in Primary Hippocampal Neurons and Primary Cardiomyocytes

Objective To detect the effects of microwave on calcium levels in primary hippocampal neurons and primary cardiomyocytes by the real-time microwave exposure combined with laser scanning confocal microscopy. Methods The primary hippocampal neurons and primary cardiomyocytes were cultured and labeled with probes, including Fluo-4 AM, Mag-Fluo-AM, and Rhod-2, to reflect the levels of whole calcium [Ca], endoplasmic reticulum calcium [Ca]ER, and mitochondrial calcium [Ca]MIT, respectively. Then, the cells were exposed to a pulsed microwave of 2.856 GHz with specific absorption rate(SAR) values of 0, 4, and 40 W/kg for 6 min to observe the changes in calcium levels. Results The results showed that the 4 and 40 W/kg microwave radiation caused a significant decrease in the levels of [Ca], [Ca]ER, and [Ca]MIT in primary hippocampal neurons. In the primary cardiomyocytes, only the 40 W/kg microwave radiation caused the decrease in the levels of [Ca], [Ca]ER, and [Ca]MIT. Primary hippocampal neurons were more sensitive to microwave exposure than primary cardiomyocytes. The mitochondria were more sensitive to microwave exposure than the endoplasmic reticulum. Conclusion The calcium efflux was occurred during microwave exposure in primary hippocampal neurons and primary cardiomyocytes. Additionally, neurons and mitochondria were sensitive cells and organelle respectively.

Effects of Electromagnetic Radiation on Autophagy and its Regulation

With the ever increasing application of electronic technology, our exposure to artificial electromagnetic energy is also rapidly increasing. Electromagnetic radiation （EMR） is the fourth largest source of pollution, after air, water, and noise.

Exposure Effects of Terahertz Waves on Primary Neurons and Neuron-like Cells Under Nonthermal Conditions

Objective This study aimed to explore the potential effects of terahertz(THz) waves on primary cultured neurons from 4 rat brain regions(hippocampus, cerebral cortex, cerebellum, and brainstem)and 3 kinds of neuron-like cells(MN9 D, PC12, and HT22 cells) under nonthermal conditions.Methods THz waves with an output power of 50(0.16 THz) and 10(0.17 THz) m W with exposure times of 6 and 60 min were used in this study. Analysis of temperature change, neurite growth, cell membrane roughness, micromorphology, neurotransmitters and synaptic-related proteins(SYN and PSD95) was used to evaluate the potential effects.Results Temperature increase caused by the THz wave was negligible. THz waves induced significant neurotransmitter changes in primary hippocampal, cerebellar, and brainstem neurons and in MN9 D and PC12 cells. THz wave downregulated SYN expression in primary hippocampal neurons and downregulated PSD95 expression in primary cortical neurons.Conclusion Different types of cells responded differently after THz wave exposure, and primary hippocampal and cortical neurons and MN9 D cells were relatively sensitive to the THz waves. The biological effects were positively correlated with the exposure time of the THz waves.

Dynamic Expression of Hyperpolarization-activated Cyclic Nucleotide-gated Cation Channel 4 Involved in Microwave Induced Pacemaker Cell Injuries

To investigate the mechanisms of microwave induced pacemaker cell injuries, Wistar rats and the primary pacemaker cells of newborn Wistar rats were exposed to microwave at average power density of 50 mW/cm2. Slower spontaneous beating rate, intercellular Ca2＋ aggregation and cell membrane perforation were detected immediately after the exposure. Moreover, hyperpolarizationactivated cyclic nucleotide-gated cation channel 4 （HCN4） was down-regulated immediately after the exposure and up-regulated at 12 h after the exposure. In the sinoatrial node （SAN） of the rats,

Inhibition of Micro RNA 219 Expression Protects Synaptic Plasticity via Activating NMDAR1, Ca MKIIγ,and p-CREB after Microwave Radiation

In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].

Real-time Assessment of Cytosolic, Mitochondrial, and Nuclear Calcium Levels Change in Rat Pheochromocytoma Cells during Pulsed Microwave Exposure Using a Genetically Encoded Calcium Indicator

Little information is available about the effects of exposure to pulsed microwaves on neuronal Ca^2＋ signaling under non-thermal conditions. In this study, rat pheochromocytoma （PC12） cells were exposed to pulsed microwaves for 6 min at a specific absorption rate （SAR） of 4 W/kg to assess possible real-time effects. During microwave exposure, free calcium dynamics in the cytosol, mitochondria, and nucleus of cells were monitored by time-lapse microfluorimetry using a genetically encoded calcium indicator （ratiometric-pericam, ratiometric-10ericam-mt,

Pathological Changes in the Sinoatrial Node Tissues of Rats Caused by Pulsed Microwave Exposure

To observe microwave induced dynamic pathological changes in the sinus nodes, wistar rats were exposed to 0, 5, 10, 50 mW/cm^2 microwave. In 10 and 50 mW/cm^2 groups, disorganized sinoatrial node cells, cell swelling, cytoplasmic condensation, nuclear pyknosis, and anachromasis, swollen, and empty mitochondria, and blurred and focally dissolved myofibrils could be detected from 1 to 28 d, while reduced parenchymal cells, increased collagen fibers, and extracellular matrix remodeling of interstitial cells were observed from 6 to 12 months. In conclusion, 10 and 50 mW/cm^2 microwave could cause structural damages in the sinoatrial node and extracellular matrix remodeling in rats.

HTR and GRIN2B Variant Associated with Cognition Dysfunction in Electric Workers

The frequency of an extremely low frequency electromagnetic field (ELF-EMF) ranges from 3 to 3, 000 Hz. Workers who are exposed to ELF-EMF include electric power installers and repairers, power plant operators, electricians, electrical fitters, other such professionals. The main work categories in an electrical company or for utility work can be defined according to the five main stages of electricity production and distribution. Studies on the central nervous system (CNS) reported depressed activity in the different neurotransmitter systems and decreased protein content in the brains of animals exposed to ELF-EMF. Some studies reported differences with respect to change in brain function after electromagnetic radiation among individuals[1].

Microwave-induced Apoptosis and Cytotoxicity of NK Cells through ERK1/2 Signaling

Objective To investigate microwave-induced morphological and functional injury of natural killer（NK） cells and uncover their mechanisms. Methods NK-92 cells were exposed to 10, 30, and 50 m W/cm^2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2 D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK（p-ERK） was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126. Results Microwave-induced morphological and ultrastructural injury, dose-dependent apoptosis（P 〈 0.001） and cell cycle arrest（P 〈 0.001） were detected at 1 h after microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 m W/cm^2 microwave exposure（P 〈 0.01）. In the 30 m W/cm^2 microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure（P 〈 0.05）. Furthermore, p-ERK was down regulated at 1 h after exposure（P 〈 0.05）, while ERK blockade significantly promoted microwave-induced apoptosis（P 〈 0.05） and downregulation of perforin（P 〈 0.01）. Conclusion Microwave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.

Dose-dependent Cardiac Dysfunction and Structural Damage in Rats after Shortwave Radiation

Objective To detect the effects of shortwave radiation on dose-dependent cardiac structure and function in rats after radiation and to elucidate the mechanism of shortwave radiation induced cardiac injury to identify sensitive indicators and prophylactic treatment.Methods One hundred Wistar rats were either exposed to 27 MHz continuous shortwave at a power density of 5,10,and 30 mW/cm^2 for 6 min or undergone sham exposure for the control(the rats had to be placed in the exposure system with the same schedules as the exposed animals,but with an inactive antenna).The Ca^2+,glutamic oxaloacetic transaminase(AST),creatine kinase(CK)and lactate dehydrogenase(LDH)content in the peripheral serum of the rats were detected by an automatic blood biochemical analyser.The electrocardiogram(ECG)of standard lead II was recorded by a multi-channel physiological recording and analysis system.The cardiac structure of rats was observed by light and electron microscopy.Results The results showed that the 5,10,and 30 mW/cm^2 shortwave radiation caused a significant increased in the levels of Ca2+,AST,CK,and LDH in the peripheral serum of rats.The cardiac structure was damaged by radiation and showed a disordered arrangement of myocardial fibres,the cavitation and swelling of myocardial mitochondria.These injuries were most significant 7 d after radiation and were not restored until 28 d after radiation.Conclusion Shortwave radiation of 5,10,and 30 mW/cm^2 can damage rat cardiac function,including damage to the tissue structure and ultrastructure,especially at the level of the myocardial fibres and mitochondria.Shortwave radiation at 5,10,and 30 mW/cm^2 induced damage to rat heart function and structure with a dose-effect relationship,i.e.,the greater the radiation dose was,the more significant the damage was.

Activation of Nrf2/NQO1 Pathway Attenuates Oxidative Stress in Neuronal Cells Induced by Microwave and Protects Neurite Development

In previous decades,people were concerned about their health because of growing environmental influences.The advancements in pulsed power technologies have increased the availability of microwave transmitters.The possible health problems caused by the widespread use of microwaves have attracted attention in recent years.

Dose-Dependent, Frequency-Dependent, and Cumulative Effects on Cardiomyocyte Injury and Autophagy of 2.856 GHz and 1.5 GHz Microwave in Wistar Rats

With the in creasing use of microwave technology in wireless communication,medical research,and other fields,the risk of energy leakage and excessive human exposure requires more attention.Exposure to a certain frequency of microwave has been found to have harmful effects on multiple organs,including the heart[1-3],which is an important organ for blood circulation and any injury to which can cause a series of adverse consequences.

Transcriptome Sequencing of mRNA and lncRNA in Hippocampal Tissues of Rats under Microwave Exposure

Microwave-related devices are commonly used.A certain dose of microwave might induce cognitive injuries[1].The frequency of mobile 4G communication and wireless networks is located in the L-band and C-band range,respectively.