Investigating the molecular mechanisms of delirium-like neuropsychiatric disorder induced by electromagnetic pulse based on bioinformatics analysis.

Electromagnetic pulse (EMP), a unique type of electromagnetic radiation, may induce diverse neuropsychiatric disorders, such as irritability, hyperkinesis, retardation of learning and memory. However, the underlying mechanism of EMP exposure on neuronal injury has not been elucidated. Here, we aimed to delineate the regulatory expression networks based on high-throughput sequencing data to explore the possible molecular mechanisms related to EMP-induced delirium-like neuropsychiatric disorder in rats. It's shown that EMP exposure induced anxiety, cognitive decline and short-term memory impairment. The expression profiles of the long noncoding RNAs (lncRNAs) and mRNAs, along with their biological function and regulatory network, were explored in rats after EMP exposure. We identified 41 differentially expressed lncRNAs (DELs) and 266 differentially expressed mRNAs (DEMs) between EMP and sham groups. Sixty-one co-expression relationships between 18 DELs and 56 DEMs were mostly associated with synapse- and metabolic-related pathways. We predicted 51 DEL-miRNA pairs and 290 miRNA-mRNA pairs using the miRanda database to constructed a DEL-miRNA-DEM network. LncRNA AABR07042999.1 and mRNA Tph2, Slc6a4, Dbh and Th were upregulated, and the contents of serotonin, dopamine and norepinephrine were increased in both PFC and HIP after EMP exposure. The current study provided a better understanding of the ceRNA network, which might reveal the pathological mechanism and provide more treatment options for the EMP-induced neurobehavioral disorder.

The increased in vivo firing of pyramidal cells but not interneurons in the anterior cingulate cortex after neuropathic pain.

Chronic pain damages the balance between excitation and inhibition in the sensory cortex. It has been confirmed that the activity of cortical glutamatergic pyramidal cells increases after chronic pain. However, whether the activity of inhibitory interneurons synchronized changed remains obscure, especially in in vivo conditions. In the present study, we checked the firing rate of pyramidal cells and interneurons in the anterior cingulate cortex, a main cortical area for the regulation of nociceptive information in mice with spared nerve injury by using in vivo multi-channel recording system. We found that the firing rate of pyramidal cells but not interneurons increased in the ACC, which was further confirmed by the increased FOS expression in pyramidal cells but not interneurons, in mice with neuropathic pain. Selectively high frequency stimulation of the ACC nociceptive afferent fibers only potentiated the activity of pyramidal cells either. Our results thus suggest that the increased activity of pyramidal cells contributes to the damaged E/I balance in the ACC and is important for the pain hypersensitivity in mice with neuropathic pain.

Isoflurane preconditioning effects on brain damage induced by electromagnetic pulse radiation through epigenetic modification of BDNF gene transcription.

BACKGROUND: The effects of electromagnetic pulse (EMP) radiation on cognitive impairment have attracted much attention, but the mechanism is still unclear. Regulation of brain-derived neurotrophic factor (BDNF) gene expression has been found to promote memory formation and neuronal survival. Isoflurane preconditioning (IP) was reported to have a neuroprotective effect. In this study, we verified the protective effect of IP against brain injury induced by EMP exposure and examined the relation of this effect with BDNF gene regulation. METHODS: Twenty-four hours before EMP exposure, rats were pretreated with 2% inhaled isoflurane for 30 minutes. At 24 hours after EMP injury, the Morris water maze test was carried out. Meanwhile, the other rats were executed and their brain tissues were used for Nissl staining, qRT-PCR, western blot and chromatin immunoprecipitation. RESULTS: The Morris water maze results showed that 2% IP improved the spatial learning and memory ability of the rats. The Nissl staining results showed 2% of IP alleviated neuronal damage. Also, we detected the mRNA and protein expression of BDNF, and 2% IP significantly increased the expression of BDNF. We also found the expression level of histone deacetylase 2 (HDAC2) was increased and that EMP exposure significantly decreased H3 acetylation, while 2% IP reversed these phenomena, individually, BDNF transcription was activated, and neurogenesis after EMP exposure was alleviated. CONCLUSIONS: Our results suggested that 2% of IP alleviates cognitive impairment induced by EMP exposure in rats. Also, the sustained elevated level of BDNF gene transcription may be an essential mechanism for stimulating neurogenesis because of the increased level of HDAC2-dependent H3 acetylation.

Isoflurane Preconditioning Attenuates Brain Injury Induced by Electromagnetic Pulse via the TLR4/NFκB Signaling Pathway.

Electromagnetic pulse (EMP) is a unique type of electromagnetic radiation, and EMP exposure causes a series of biological effects. The nervous system is sensitive to EMP. We studied the neuroprotective effects of isoflurane preconditioning against EMP exposure and used hematoxylin-eosin staining (HE) to observe the effects of electromagnetic pulse and isoflurane preconditioning on neurons. Inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). Western blotting was used to detect the expression of caspase-3, CD11b, TLR4, and NFκBp65. We found that after EMP exposure, the number of abnormal neurons had increased, and the expression of caspase-3, CD11b, TLR4, and NFκBp65 had also increased. Isoflurane preconditioning can reverse the above phenomenon. Moreover, we found that isoflurane preconditioning can reduce neuronal apoptosis and improve cognitive impairment induced by EMP. These findings indicate that isoflurane preconditioning can protect neurons in the cerebral cortex from EMP exposure, alleviate the inflammatory reaction and cell apoptosis, and improve cognitive impairment induced by EMP. These effects may occur through the downregulation of the TLR4/NFκB signaling pathway and the inhibition of microglial activation.