Unveiling the biological effects of radio-frequency and extremely-low frequency electromagnetic fields on the central nervous system performance.

Introduction: Radiofrequency electromagnetic radiation (RF-EMR) and extremely low-frequency electromagnetic fields (ELF-EMF) have emerged as noteworthy sources of environmental pollution in the contemporary era. The potential biological impacts of RF-EMR and ELF-EMF exposure on human organs, particularly the central nervous system (CNS), have garnered considerable attention in numerous research studies. Methods: This article presents a comprehensive yet summarized review of the research on the explicit/implicit effects of RF-EMR and ELF-EMF exposure on CNS performance. Results: Exposure to RF-EMR can potentially exert adverse effects on the performance of CNS by inducing changes in the permeability of the blood-brain barrier (BBB), neurotransmitter levels, calcium channel regulation, myelin protein structure, the antioxidant defense system, and metabolic processes. However, it is noteworthy that certain reports have suggested that RF-EMR exposure may confer cognitive benefits for various conditions and disorders. ELF-EMF exposure has been associated with the enhancement of CNS performance, marked by improved memory retention, enhanced learning ability, and potential mitigation of neurodegenerative diseases. Nevertheless, it is essential to acknowledge that ELF-EMF exposure has also been linked to the induction of anxiety states, oxidative stress, and alterations in hormonal regulation. Moreover, ELF-EMR exposure alters hippocampal function, notch signaling pathways, the antioxidant defense system, and synaptic activities. Conclusion: The RF-EMR and ELF-EMF exposures exhibit both beneficial and adverse effects. Nevertheless, the precise conditions and circumstances under which detrimental or beneficial effects manifest (either individually or simultaneously) remain uncertain.

The Auditory Brainstem Response (ABR) Test, Supplementary to Behavioral Tests for Evaluation of the Salicylate-Induced Tinnitus.

Tinnitus is a symptom of various disorders that affects the quality of life of millions people. Given the significance of the access to an objective and non-invasive method for tinnitus detection, in this study the auditory brainstem response (ABR) electrophysiological test was used to diagnose salicylate-induced tinnitus, in parallel with common behavioral tests. Wistar rats were divided into saline (n = 7), and salicylate (n = 7) groups for behavioral tests, and salicylate group (n = 5) for the ABR test. The rats were evaluated by pre-pulse inhibition (PPI), gap pre-pulse inhibition of the acoustic startle (GPIAS), and ABR tests, at baseline, 14 and 62 h after salicylate (350 mg/kg) or vehicle injection. The mean percentage of GPIAS test was significantly reduced following salicylate administration, which confirms the induction of tinnitus. The ABR test results showed an increase in the hearing threshold at click and 8, 12, and 16 kHz tones. Moreover, a decline was observed in the latency ratio of II-I waves in all tone burst frequencies with the highest variation in 12 and 16 kHz as well as a decrement in the latency ratio of III-I and IV-I only in 12 and 16 kHz. ABR test is able to evaluate the salicylate induced tinnitus pitch and confirm the results of behavioral tinnitus tests. GPIAS reflexive response is dependent on brainstem circuits and the auditory cortex while, ABR test can demonstrate the function of the auditory brainstem in more details, and therefore, a combination of these two tests can offer a more accurate tinnitus evaluation.

Chemical Compositions and Experimental and Computational Modeling of the Anticancer Effects of Cnidocyte Venoms of Jellyfish Cassiopea andromeda and Catostylus mosaicus on Human Adenocarcinoma A549 Cells.

Nowadays, major attention is being paid to curing different types of cancers and is focused on natural resources, including oceans and marine environments. Jellyfish are marine animals with the ability to utilize their venom in order to both feed and defend. Prior studies have displayed the anticancer capabilities of various jellyfish. Hence, we examined the anticancer features of the venom of Cassiopea andromeda and Catostylus mosaicus in an in vitro situation against the human pulmonary adenocarcinoma (A549) cancer cell line. The MTT assay demonstrated that both mentioned venoms have anti-tumoral ability in a dose-dependent manner. Western blot analysis proved that both venoms can increase some pro-apoptotic factors and reduce some anti-apoptotic molecules that lead to the inducing of apoptosis in A549 cells. GC/MS analysis demonstrated some compounds with biological effects, including anti-inflammatory, antioxidant and anti-cancer activities. Molecular docking and molecular dynamic showed the best position of each biologically active component on the different death receptors, which are involved in the process of apoptosis in A549 cells. Ultimately, this study has proven that both venoms of C. andromeda and C. mosaicus have the capability to suppress A549 cells in an in vitro condition and they might be utilized in order to design and develop brand new anticancer agents in the near future.

Fabricating an electroactive injectable hydrogel based on pluronic-chitosan/aniline-pentamer containing angiogenic factor for functional repair of the hippocampus ischemia rat model.

The hippocampus, a critical cerebral region involved in learning and memory formation, is especially vulnerable to ischemic defect. Here, we developed an injectable electroactive hydrogel based on pluronic-chitosan/aniline-pentamer with proper conductivity around 10-4 S/cm to achieve the functional repair of the hippocampus following the ischemic defect. FTIR, DSC, and TGA measurements were performed to assess the chemical structure and thermal stability of the synthesized hydrogel. Aniline pentamer decreased the swelling capacity, degradation, and drug release rate. Further, contact angle, melting point, and gelation time of hydrogels were enhanced by addition of aniline oligomer. Moreover, it endowed the on-demand electro-responsive drug release. Injectability of hydrogel was evaluated by rheometry, exhibiting proper gelling time at the body temperature. The ionic/electrical conductivity and desired in vitro biocompatibility with PC12 cells were also achieved. Injection of VEGF-loaded electroactive hydrogel in the hippocampal ischemic animal model resulted in decreased infarction volume, improved hippocampal dependent learning, and memory performance. Taken all together, the results confirmed that fabricated injectable hydrogel would be a suitable candidate for ischemic defect treatment and can lead to new horizons to treat neurological disorders.

Neurogenic differentiation of human dental pulp stem cells by optogenetics stimulation.

INTRODUCTION: Human dental pulp stem cells (hDPSCs), a promising source for autologous transplantation in regenerative medicine, have been shown to be able to differentiate into neural precursors. Optogenetics is considered as an advanced biological technique in neuroscience which is able to control the activity of genetically modified stem cells by light. The purpose of this study is to investigate the neurogenic differentiation of hDPSCs following optogenetic stimulation. METHODS: The hDPSCs were isolated by mechanical enzymatic digestion from an impacted third molar and cultured in DMEM/F12. The cells were infected with lentiviruses carrying CaMKIIa-hChR2 (H134R). Opsin-expressing hDPSCs were plated at the density of 5 × 104 cells/well in 6-well plates and optical stimulation was conducted with blue light (470 nm) pulsing at 15 Hz, 90 % Duty Cycle and 10 mW power for 10 s every 90 minutes, 6 times a day for 5 days. Two control groups including non-opsin-expressing hDPSCs and opsin-expressing hDPSCs with no optical stimulation were also included in the study. A day after last light stimulation, the viability of cells was analyzed by the MTT assay and the morphological changes were examined by phase contrast microscopy. The expression of Nestin, Microtubule-Associated protein 2 (MAP2) and Doublecortin (DCX) were examined by immunocytochemistry. RESULTS: Human DPSCs expressed the reporter gene, mCherry, 72 hours after lentiviral infection. The result of MTT assay revealed a significant more viability in optical stimulated opsin-expressing hDPSCs as compared with two control groups. Moreover, optical stimulation increased the expression of Nestin, Doublecortin and MAP2 along with morphological changes from spindle shape to neuron-like shape. CONCLUSION: Optogenetics stimulation through depolarizing the hDPSCs can increase the cells viability and/or proliferation and also promote the differentiation toward neuron-like cells.

Optogenetic Stimulation of the Anterior Cingulate Cortex Ameliorates Autistic-Like Behaviors in Rats Induced by Neonatal Isolation, Caudate Putamen as a Site for Alteration.

Epigenetic agents, such as neonatal isolation during neurodevelopmental period of life, can change various regions of the brain. It may further induce psychological disorders such as autistic-like phenomena. This study indicated the role of chronic increased anterior cingulate cortex (ACC) output on alteration of caudate putamen (CPu) as a main behavior regulator region of the brain in adult maternal deprived (MD) rats. For making an animal model, neonates were isolated from their mothers in postnatal days (PND 1-10, 3 h/day). Subsequently, they bilaterally received pLenti-CaMKIIa-hChR2 (H134R)-mCherry-WPRE virus in ACC area via stereotaxic surgery in PND50. After 22 days, these regions were exposed to blue laser (473 nm) for six consecutive days (15 min/day). Then, behavioral deficits were tested and were compared with control group in the following day. Animals were immediately killed and their brains were prepared for tissue processing. Results showed that neonatal isolation induces autistic-like behaviors and leads to overexpression of NMDAR1 and Nox2-gp91phox proteins and elevation of catalase activity in the CPu regions of the adult offspring compared with control group. Chronic optogenetic stimulation of ACC neurons containing (ChR2+) led to significant reduction in the appearance of stereotypical behavior and alien-phobia in MD rats. The amount of NMDAR1 and Nox2-gp91phox expression and the catalase activity in CPu were reduced after this treatment. Therefore, autistic-like behavior seems to be related with elevation of NMDAR1 and Nox2-gp91phox protein levels that enhance the effect of glutamatergic projection on CPu regions. Optogenetic treatment also could ameliorate behavioral deficits by modulating these protein densities.

Modeling traumatic injury in organotypic spinal cord slice culture obtained from adult rat.

Nowadays there are various models of spinal cord injury (SCI) that recreate mechanisms of human SCI. The ex vivo modeling of injury is a robust approach, confronts with less experimental and ethical challenges. Currently almost all ex vivo models are obtained either from embryonic or postnatal animals, which can hardly mimic features of human SCI. This study was designed to develop SCI in slice culture of adult rats. Here, the lumbar enlargement of an adult rat was sliced and cultured. After seven days in vitro, a weight was dropped to simulate the injury. The result showed that although the rate of cell death in first days of in vitro was high, it reduced after 7 days and dropping a weight at the time caused significant rate of cell death in slices. It was shown that injury can disturb histological features and neuronal integrity in the slices. Treating the injured slices with valproic acid resulted in a significant decrease of TNF-α and increase of BDNF expression. Collected data revealed obtained slices from adult rat were able to adjust to the culture environment after 7 days and dropping a weight at the time point could simulate the injury. Besides mimicking the disturbing features of human SCI, this model can response to VPA pharmacological treatment.

Photothrombotically induced unilateral selective hippocampal ischemia in rat.

INTRODUCTION: The vulnerability of hippocampal formation to ischemic insult has been documented in both humans and animal models. Ischemic injury induction through photothrombosis is an invasive and reproducible model of ischemic stroke which provides the ability to induce ischemia selectively in any desired area. In this study, we describe a method to induce selective unilateral hippocampal ischemia in rat through modified photothrombotic model. METHODS: Male wistar rats (n = 66) were subjected to stereotaxic surgery to insert a guide cannula just above the ascending part of hippocampal fissure. After recovery femoral vein was cannulated and rats were mounted in stereotaxic frame to optical fiber insertion in guide cannula and illumination of hippocampal fissure for 25 min. Rose Bengal dye was slowly injected through femoral vein during the first two-minute of illumination. Twenty-four hours later, infarct volume and histological change were evaluated in rat hippocampus. Cognitive function was also evaluated 48 h after ischemia induction. RESULTS: This procedure caused significant neuronal necrosis and infarct formation in the right hemisphere hippocampus. The infarct size was consisted in different subjects and was paralleled to cognitive impairment. The mean volume of infarction was 6.5% which affected whole right hippocampus and caused significant cognitive impairment compared to sham group (P < 0.001). DISCUSSION: The method described in this study provides the ability of selective hippocampal ischemia induction and study of hippocampal injury consequences following ischemia or other neurodegenerative disease that affect hippocampus.

Neuroprotective effect of monophosphoryl lipid A, a detoxified lipid A derivative, in photothrombotic model of unilateral selective hippocampal ischemia in rat.

Finding a neuroprotective strategy to rescue patients suffering from acute brain damage is of great interest. Monophosphoryl lipid A (MPL) is a derivative of lipopolysaccharide (LPS) that lacks many of the endotoxic properties of the parent molecule, and yet has similar protective effect. Here, we report the first evidence that MPL preconditioning, similar to LPS preconditioning, can induce neuroprotection against cerebral ischemia. MPL (0.5, 1, 5 µg/rat) was injected unilaterally into the left cerebral ventricle of male rats, and 48 h later, rats were subjected to ipsilateral selective hippocampal ischemia using a modified version of the photothrombotic method. The neuroprotective effects of MPL and LPS were evaluated by measuring infarct size and assessing cognitive function. The expression level of some inflammatory and anti-inflammatory cytokines involving in TLR4 signaling pathway was also measured. Cognitive impairment and infarct size were obvious in control group receiving normal saline intracerebroventricularly and then selective hippocampal ischemia, compared to the sham group. Immunologic preconditioning with MPL or LPS significantly reduced infarct size and improved cognitive function. Additionally, immunologic preconditioning resulted in inflammatory mediators, NF-κB and TNF-α, down-regulation but anti-inflammatory mediators, IRF3, IFN-ß, and TGF-ß, up-regulation. Our data showed that both MPL and LPS preconditioning may reprogram the TLR4 signaling pathway to produce a cytokine profile which eventually leads to neuroprotection against ischemia injury. MPL, unlike LPS, is safe and well tolerated in clinic, thus it could be considered as a new approach in prevention or even treatment of cerebral ischemic insult consequences.