Effects of pulsed electromagnetic fields on learning and memory abilities of STZ-induced dementia rats

Research on the safety risks of microwave irradiation on motion balance perception in electric power environments

To the microwave irradiation safety hazards caused by the co-construction of towers in smart grids, this paper investigates the effects of microwave irradiation in the power environment on the biological motion balance perception function. Firstly, simulation of microwave signals in the electric power environment, i.e., low-frequency harmonics and high-frequency carriers, were realized by signal modulation and applied in four types of behavior testing scenarios. Then, determining rats as target organisms to replace workers and randomly dividing into groups in proportion: open field, rotating rod fatigue, beam walking and forced swimming. Configuring radar with various parameters to match the electric power irradiation scene and stimulate rats, monitoring the abnormal behavior by image processing module, including posture, motion trajectory, distance, and other features. The experimental result showed that exposed to microwaves induce rats motor ability decline, balance perception imbalance, together with paralysis within long-term exposure, and its locomotor activity, coordination, posture control and reaction time all exhibit varying degrees of weakening. These findings indicate that microwave irradiation in electric power environment may pose significant health and safety risks for worker.

Neurobiological effects and mechanisms of magnetic fields: a review from 2000 to 2023

Magnetic fields are widely used in medical diagnostics because of their superior non-invasive properties. In addition, with the widespread use of magnetic fields in transportation and other areas, their potential hazards to human health and the assessment of their safety have attracted considerable attention. The effects of magnetic fields on living organisms have a long history. The biological effects of magnetic field exposure in mice and rats depend on the magnetic field strength, exposure time, and direction; depending on these and potentially other factors, magnetic fields can cause a series of neurobiological effects. We reviewed global research on the neurobiological effects of magnetic fields from recent years to provide an overview and insights into the underlying mechanisms. This review focuses on the biological effects of static and dynamic magnetic fields of different frequencies and intensities on animals and nerve cells and their mechanisms of action.

A review on the consequences of molecular and genomic alterations following exposure to electromagnetic fields: Remodeling of neuronal network and cognitive changes

The use of electromagnetic fields (EMFs) is essential in daily life. Since 1970, concerns have grown about potential health hazards from EMF. Exposure to EMF can stimulate nerves and affect the central nervous system, leading to neurological and cognitive changes. However, current research results are often vague and contradictory. These effects include changes in memory and learning through changes in neuronal plasticity in the hippocampus, synapses and hippocampal neuritis, and changes in metabolism and neurotransmitter levels. Prenatal exposure to EMFs has negative effects on memory and learning, as well as changes in hippocampal neuron density and histomorphology of hippocampus. EMF exposure also affects the structure and function of glial cells, affecting gate dynamics, ion conduction, membrane concentration, and protein expression. EMF exposure affects gene expression and may change epigenetic regulation through effects on DNA methylation, histone modification, and microRNA biogenesis, and potentially leading to biological changes. Therefore, exposure to EMFs possibly leads to changes in cellular and molecular mechanisms in central nervous system and alter cognitive function.

A regulatory pathway model of neuropsychological disruption in Havana syndrome

Introduction

In 2016 diplomatic personnel serving in Havana, Cuba, began reporting audible sensory phenomena paired with onset of complex and persistent neurological symptoms consistent with brain injury. The etiology of these Anomalous Health Incidents (AHI) and subsequent symptoms remains unknown. This report investigates putative exposure-symptom pathology by assembling a network model of published bio-behavioral pathways and assessing how dysregulation of such pathways might explain loss of function in these subjects using data available in the published literature. Given similarities in presentation with mild traumatic brain injury (mTBI), we used the latter as a clinically relevant means of evaluating if the neuropsychological profiles observed in Havana Syndrome Havana Syndrome might be explained at least in part by a dysregulation of neurotransmission, neuro-inflammation, or both.

Method

Automated text-mining of >9,000 publications produced a network consisting of 273 documented regulatory interactions linking 29 neuro-chemical markers with 9 neuropsychological constructs from the Brief Mood Survey, PTSD Checklist, and the Frontal Systems Behavior Scale. Analysis of information flow through this network produced a set of regulatory rules reconciling to within a 6% departure known mechanistic pathways with neuropsychological profiles in N = 6 subjects.

Results

Predicted expression of neuro-chemical markers that jointly satisfy documented pathways and observed symptom profiles display characteristically elevated IL-1B, IL-10, NGF, and norepinephrine levels in the context of depressed BDNF, GDNF, IGF1, and glutamate expression (FDR < 5%). Elevations in CRH and IL-6 were also predicted unanimously across all subjects. Furthermore, simulations of neurological regulatory dynamics reveal subjects do not appear to be "locked in" persistent illness but rather appear to be engaged in a slow recovery trajectory.

Discussion

This computational analysis of measured neuropsychological symptoms in Havana-based diplomats proposes that these AHI symptoms may be supported in part by disruption of known neuroimmune and neurotransmission regulatory mechanisms also associated with mTBI.

Cognitive improvement via a modulated rhythmic pulsed magnetic field in D-galactose-induced accelerated aging mice

Rhythmic physical stimulations have emerged as effective noninvasive intervention strategies in the treatment of pathological cognitive deficits. Transcranial magnetic stimulation (TMS) can regulate neural firing and improve the learning and memory abilities of rodents or patients with cognitive deterioration. However, the effects of elaborate magnetic stimulation with low intensity during aging or other neurological disordering processes on cognitive decline remain unclear. In this study, we developed an elaborate modulated pulsed magnetic field (PMF) stimulation with a complex pattern in the theta repeated frequency and gamma carrier frequency and then determined the effects of this rhythmic PMF on the cognitive function of accelerated aging mice established by chronic subcutaneous injection of D-galactose (D-gal). The results of the Morris water maze (MWM) test showed that mice treated with modulated PMF displayed shorter swimming distance and latency time in the spatial exploration acquisition trial and exhibited a significant preference in the target presumptive platform area in the probe trial, all of which indicated the enhancement in spatial learning and memory abilities upon PMF stimulation of the accelerated aging mice. The novel object recognition (NOR) test results showed a similar tendency as the MWM results although without statistical significance. Further determination of histological structures demonstrated that the cognitive function-related hippocampal CA3 neurons degenerated upon D-gal injection, which could also be partially rescued by PMF application. In comparison with the high-intensity TMS approach, low-intensity magnetic stimulation could be much safer and allow deeper penetration without adverse effects such as seizure. In summary, modulated PMF, even with low intensity, could effectively improve rodent cognitive functions impaired by D-gal-induced accelerated aging, which might provide a new safe therapeutic strategy for cognitive deficits as well as other neurological disorders.

Dapagliflozin diminishes memory and cognition impairment in Streptozotocin induced diabetes through its effect on Wnt/β-Catenin and CREB pathway

Diabetic neuropathy is a chronic condition that affects a significant number of individuals with diabetes. Streptozotocin injection intraperitoneally to rodents produces pancreatic islet β-cell destruction causing hyperglycemia, which affect the brain leading to memory and cognition impairment. Dapagliflozin may be able to reverse beta-cell injury and alleviate this impairment. This effect may be via neuroprotective effect or possible involvement of the antioxidant, and anti-apoptotic properties. Forty rats were divided into four groups as follows: The normal control group, STZ-induced diabetes group, STZ-induced diabetic rats followed by treatment with oral dapagliflozin group and normal rats treated with oral dapagliflozin. Behavioral tests (Object location memory task and Morris water maze) were performed. Serum biomarkers (blood glucose and insulin) were measured and then the homeostatic model assessment for insulin resistance (HOMA-IR) was calculated. In the hippocampus the followings were determined; calmodulin, ca-calmodulin kinase Ⅳ (CaMKIV), protein kinase A (PKA) and cAMP-responsive element-binding protein to determine the transcription factor CREB and its signaling pathway also Wnt signaling pathway and related parameters (WnT, B-catenin, lymphoid enhancer binding factor LEF, glycogen synthase kinase 3β). Moreover, nuclear receptor-related protein-1, acetylcholine and its hydrolyzing enzyme acetylcholine esterase, oxidative stress parameter malondialdehyde (MDA) and apoptotic parameter caspase-3 were determined. STZ was able to cause destruction to pancreatic β-cells which was reflected on glucose levels causing diabetes. Diabetic neuropathy was clear in the rats performing the behavioral tests. Memory and cognition parameters in the hippocampus were negatively affected. Oxidative stress and apoptotic parameter were elevated while the electrical activity was declined. Dapagliflozin was able to reverse the previously mentioned parameters and behavior. Thus, to say dapagliflozin significantly showed neuroprotective action along with antioxidant, and anti-apoptotic properties.

Jiedu-Yizhi Formula Improves Cognitive Impairment in an Aβ 25-35-Induced Rat Model of Alzheimer's Disease by Inhibiting Pyroptosis

Jiedu-Yizhi formula (JDYZF) is prescribed for the treatment of Alzheimer's disease (AD) and was created by Jixue Ren, a master of traditional Chinese medicine, based on the "marrow deficiency and toxin damage" theory. In our clinic, this formula has been used for the treatment of AD for many years and has achieved good results. However, the mechanism by which JDYZF improves cognitive impairment has not been determined. In this study, we confirmed that orally administered JDYZF reversed the cognitive deficits in an Aβ _25-35-induced rat model, increased the number of neurons in the hippocampal CA1 area, improved their structure, decreased the deposition of β-amyloid (Aβ), reduced the expression of proteins related to the NLRP3/Caspase-1/GSDMD and LPS/Caspase-11/GSDMD pyroptosis pathways, and reduced the levels of interleukin 1β (IL-1β) and IL-18, thereby inhibiting the inflammatory response. In addition, JDYZF exerted no hepatotoxicity in rats. In short, these results provide scientific support for the clinical use of JDYZF to improve the cognitive function of patients with AD.

Electromagnetic field protects against cognitive and synaptic plasticity impairment induced by electrical kindling in rats

Kindling results in abnormal synaptic potentiation and significant impairment in learning and memory. Electromagnetic field (EMF) effects on learning and memory in kindled animals and its effects on hippocampal neural activity are largely unknown. In the current study, the effects of EMF on learning and memory, as well as hippocampal synaptic plasticity, in kindled rats were investigated. EMF (10 mT; 100 Hz) was applied to fully kindled animals one hour/day for a period of one week. The behavioral and electrophysiological studies were performed 24 h following the EMF application. The kindled rats showed spatial learning deficits during the training phase of the Morris water maze (MWM) test. Moreover, there were increments in escape latency and path length compared to the sham group. The kindled rats spent less time in the target-quadrant probe test, indicating spatial memory impairment. Applying EMF to the KEMF group (kindling + EMF) restored learning and memory, and decreased escape latency and path length significantly compared to the kindled group. EMF alone had no significant effects on the learning and memory parameters. Based on the open field (OF) test results, EMF alone in the EMF group, but not in the kindled or the KEMF groups, decreased the total traveled distance and increased the spent time in the peripheral zone, compared to the sham group. Based on electrophysiological results, applying EMF in the KEMF group returned the ability of synaptic potentiation to the hippocampal CA1 area and high-frequency stimulation induced long-term potentiation (LTP). Accordingly, EMF can be considered a potential therapy for seizure-induced deficits in learning and memory.

Exposure to Static and Extremely-Low Frequency Electromagnetic Fields and Cellular Free Radicals

This paper summarizes studies on changes in cellular free radical activities from exposure to static and extremely-low frequency (ELF) electromagnetic fields (EMF), particularly magnetic fields. Changes in free radical activities, including levels of cellular reactive oxygen (ROS)/nitrogen (RNS) species and endogenous antioxidant enzymes and compounds that maintain physiological free radical concentrations in cells, is one of the most consistent effects of EMF exposure. These changes have been reported to affect many physiological functions such as DNA damage; immune response; inflammatory response; cell proliferation and differentiation; wound healing; neural electrical activities; and behavior. An important consideration is the effects of EMF-induced changes in free radicals on cell proliferation and differentiation. These cellular processes could affect cancer development and proper growth and development in organisms. On the other hand, they could cause selective killing of cancer cells, for instance, via the generation of the highly cytotoxic hydroxyl free radical by the Fenton Reaction. This provides a possibility of using these electromagnetic fields as a non-invasive and low side-effect cancer therapy. Static- and ELF-EMF probably play important roles in the evolution of living organisms. They are cues used in many critical survival functions, such as foraging, migration, and reproduction. Living organisms can detect and respond immediately to low environmental levels of these fields. Free radical processes are involved in some of these mechanisms. At this time, there is no credible hypothesis or mechanism that can adequately explain all the observed effects of static- and ELF-EMF on free radical processes. We are actually at the impasse that there are more questions than answers.