Magnesium Acts as a Second Messenger in the Regulation of NMDA Receptor-Mediated CREB Signaling in Neurons

Quantitative analysis of the interaction between NMDA and AMPA receptors in glutamatergic synapses based on mathematical model

NMDA and AMPA receptors are co-localized at most glutamatergic synapses, where their numbers and distribution undergo dynamic changes. Glutamate binds to both the NMDA and AMPA receptors. Initially, I investigated whether there is competition between AMPA receptors and N-methyl-D-aspartic acid (NMDA) receptors for glutamate. Subsequently, I examined how these dynamic receptor changes affect synaptic response. To test the hypothesis, a synaptic model incorporating coexisting NMDA and AMPA receptors within the postsynaptic density (PSD) was developed. During long-term potentiation (LTP) induction, the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the PSD increase. If there is competition for glutamate between AMPA receptors and NMDA receptors, the number of activated NMDA receptor channels will decrease. Since LTP induction relies on the activation of NMDA receptors, reducing their activation will raise the threshold for LTP induction. Consequently, the LTP of the synapse itself can establish negative feedback, preventing excessive dynamics and maintaining the stability of the neural network.

Magnesium and Migraine

Migraine is a widespread and intricate neurological condition that involves various factors and is marked by recurring headache episodes. Migraine is among the ten neurological conditions accounting for the greatest disability in the whole population, the leading cause of disability for children and adolescents aged 5-19 years, and the second cause of disability for adults aged 20-59 years. Magnesium deficiency is also a very common condition resulting from diverse reasons, including insufficient dietary consumption or increased loss through the gastrointestinal or renal system. Accumulated evidence from case reports, case-control studies, observational studies, and randomized, placebo-controlled trials has shown the effectiveness of magnesium supplementation in alleviating migraine, both acutely and chronically. Mechanisms that may help explain these results include the potential link between magnesium deficit and spreading cortical depression, vascular changes, oxidative stress, chronic inflammation, nervous excitation, neurotransmitter release, and electrolyte imbalances. This article aims to provide a comprehensive review of the available evidence on the links between magnesium and migraine, considering the role of magnesium in the pathogenesis of migraine and the utility of magnesium in its prevention and treatment.

The Neurometabolic Function of the Dopamine-Aminotransferase System

BACKGROUND/OBJECTIVES

The neurometabolic function is controlled by a complex multi-level physiological system that includes neurochemical, hormonal, immunological, sensory, and metabolic components. Functional disorders of monoamine systems are often detected in clinical practice together with metabolic dysfunctions. An important part of the mentioned pathological conditions are associated with disturbances in protein metabolism, some of the most important biomarkers which are aminotransferases and transcription factors that regulate and direct the most important metabolic reactions. Another important part of energy metabolism is the dopamine-mediated regulation of protein metabolism.

METHODS

The review describes research results into the dopamine-mediated mechanism of metabolic regulation in humans and animals. Particular attention is paid to the neurometabolic mechanisms of protein metabolism.

RESULTS

The dopamine-aminotransferase system of the energy metabolism regulation is a separate, independent, regulatory and diagnostically significant biochemical pathway controlled by the hormonal system, the key hormone is cortisol, the key neurotransmitter is dopamine, the key transcription factor is CREB, and the key regulatory enzymes are alanine aminotransferase, aspartate aminotransferase, and tyrosine aminotransferase.

CONCLUSIONS

This review presents an original study describing the discovery of a new regulatory mechanism for neurometabolic physiological function in humans and animals. A key part of this mechanism is the dopamine-aminotransferase system.

Magnesium-Impregnated Membrane Promotes Bone Regeneration in Rat Skull Defect by N-Linked Glycosylation of SPARC via MagT1

Autograft has long been the gold standard for various bone surgeries. Nevertheless, the increasing usage of synthetic implants is taking over the operation rooms due to biosafety and standardized protocols. To fulfill such tremendous needs, a magnesium-impregnated membrane is devised that steadily releases magnesium ions to stimulate osteogenesis. The compatibility of Magnesium oxide (MgO) particles is enhanced through hydration and grafting, characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). With detailed degradation profiles, an in-depth investigation of Magnesium transporter 1 (MagT1) for magnesium intake is carried out and engaging in the N-linked glycosylation by using RNAi and inhibitors. The glycosylation of secreted protein acidic and rich in cysteine (SPARC) affected extracellular secretion and mineral deposition, demonstrated by immunostaining and density-dependent color-SEM (DDC-SEM). Skull defects are treated by implanting magnesium-impregnated membranes in rats and evaluated them by micro-CT and histological exams. This study revealed the compatible integration of grafted magnesium hydroxide (g-MH) particles is the key to functional performance and critical to applicability in vivo; meanwhile, it opens the door to a biological rationale for designing biomimetic materials.

Early-life bisphenol A exposure causes detrimental age-related changes in anxiety, depression, learning, and memory in juvenile and adult male rats: Involvement of NMDAR/PSD-95-PTEN/AKT signaling pathway

Bisphenol A (BPA) is an endocrine disruptor monomer that is widely used in the manufacturing of epoxy resins and polycarbonate plastics. Several lines of evidence indicate the function of the pre- or perinatally PI3K/AKT signaling pathway in the development of psychiatric disorders. The present study aimed to evaluate for the first time the effect of modifying the NMDAR/PSD-95-PTEN/AKT signaling pathway on behavioral and synaptic plasticity of early-life BPA exposure and its long-lasting influence on juvenile and adulthood stages of development. We investigated the effects of oral BPA doses of 50 and 125 mg/kg/day on the prefrontal cortex (PFC) and hippocampus of male Sprague Dawley rats from postnatal day (PND) 18-60 and PND 18-95, which correspond to juvenile and adolescent stages, respectively. Subsequently, we performed a series of rat behavioral tests, including the open field, elevated plus-maze, forced swimming, and Y-maze. Notably, neurotransmitter levels such as dopamine, serotonin, and gamma-aminobutyric acid, levels of postsynaptic density protein 95 and cAMP response element-binding protein, as well as mRNA levels of N-methyl-D-aspartate receptor subunits, fluctuated between reduction and elevation in the PFC and hippocampus. Furthermore, phosphatase and tensin (PTEN) mRNA and protein levels were upregulated in both brain areas, while PI3K, protein kinase B (AKT) and mammalian target of rapamycin (mTOR) mRNA and protein levels were decreased. Finally, our findings indicate that postnatal BPA exposure promotes long-term anxiety and depressive-like behaviors, as well as cognitive impairment, via modulation of the NMDAR/PSD-95-PTEN/AKT pathway. These findings could help to elucidate the potential developmental and neurobehavioral effects of early-life BPA exposure.

The Influence of Anesthesia on Neuromonitoring During Scoliosis Surgery: A Systematic Review

BACKGROUND

Intraoperative neuromonitoring (IONM) is crucial for the safety of scoliosis surgery, providing real-time feedback on the spinal cord and nerve function, primarily through motor-evoked potentials (MEPs). The choice of anesthesia plays a crucial role in influencing the quality and reliability of these neuromonitoring signals. This systematic review evaluates how different anesthetic techniques-total intravenous anesthesia (TIVA), volatile anesthetics, and regional anesthesia approaches such as Erector Spinae Plane Block (ESPB), spinal, and epidural anesthesia-affect IONM during scoliosis surgery.

METHODS

A systematic review was conducted following PRISMA guidelines. PubMed, MEDLINE, EMBASE, and Cochrane databases were searched for studies published between 2017 and 2024 that examined the impact of anesthetic techniques on neuromonitoring during scoliosis surgery. The focus was on studies reporting MEP outcomes, anesthetic protocols, and postoperative neurological and analgesic effects.

RESULTS

The search initially identified 998 articles. After applying inclusion criteria based on relevance, recency, methodological quality, and citation frequency, 45 studies were selected for detailed review.

CONCLUSION

The erector Spinae Plane Block (ESPB) provides distinct benefits over spinal and epidural anesthesia in scoliosis surgery, particularly in maintaining neuromonitoring accuracy, reducing hemodynamic instability, and minimizing complications. The ESPB's ability to deliver effective segmental analgesia without compromising motor function makes it a safer and more efficient option for postoperative pain management, enhancing patient outcomes.

Magnesium (Mg) and Neurodegeneration: A Comprehensive Overview of Studies on Mg Levels in Biological Specimens in Humans Affected Some Neurodegenerative Disorders with an Update on Therapy and Clinical Trials Supplemented with Selected Animal Studies

Neurodegenerative diseases, characterized by neuron loss, are a group of neurological disorders that adversely affect the lives of millions of people worldwide. Although several medicines have been approved for managing neurodegenerative diseases, new therapies allowing for a significant slowdown in the progression of neurodegenerative syndromes are constantly being sought. Magnesium (Mg), a crucial mineral necessary for the functioning of organisms, is important to normal central nervous system (CNS) activity. Although the effects of this bioelement on the CNS are relatively well recognized, its role in the pathophysiology of neurological disorders in humans is not yet well characterized. Therefore, the main goal of this review is to collect data about a possible association between Mg and neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's Disease (PD), and Amyotrophic lateral sclerosis (ALS) in humans. Hence, the levels of Mg in blood, cerebrospinal fluid (CSF), urine, and hair from subjects with AD, PD, and ALS are compiled to detect possible variations in the levels of this mineral in the biological specimens of people with neurodegenerative illnesses. Additionally, the findings from an animal model are summarized to offer the reader a deeper insight into studies on Mg in the context of neuroprotection and neurodegeneration. Data provided in the present review indicate that Mg, due to its neuroprotective, antioxidant, anti-inflammatory, and mitochondrial-supportive properties, could be a potential therapeutic agent for AD, PD, and ALS. However, more epidemiological studies with standardized methods of dietary assessment and Mg measurement are necessary to recognize its exact role in neurodegenerative disorders. Moreover, extensive well-designed clinical trials are also needed to establish definitive therapeutic protocols and optimal dosages, and to ensure long-term safety of this mineral supplementation in AD, PD, and ALS patients.

Therapeutic potential of ketamine in management of epilepsy: Clinical implications and mechanistic insights

Epilepsy, a widespread neurological disorder, affects approximately 50 million people worldwide. This disorder is typified by recurring seizures due to abnormal neuron communication in the brain. The seizures can lead to severe ischemia and hypoxia, potentially threatening patients' lives. However, with proper diagnosis and treatment, up to 70 % of patients can live without seizures. The causes of epilepsy are complex and multifactorial, encompassing genetic abnormalities, structural brain anomalies, ion channel dysfunctions, neurotransmitter imbalances, neuroinflammation, and immune system involvement. These factors collectively disrupt the crucial balance between excitation and inhibition within the brain, leading to epileptic seizures. The management of treatment-resistant epilepsy remains a considerable challenge, necessitating innovative therapeutic approaches. Among emerging potential treatments, ketamine-a drug traditionally employed for anesthesia and depression-has demonstrated efficacy in reducing seizures. It is noteworthy that, independent of its anti-epileptic effects, ketamine has been found to improve the balance between excitatory and inhibitory (E/I) activities in the brain. The balance is crucial for maintaining normal neural function, and its disruption is widely considered a key driver of epileptic seizures. By acting on N-methyl-D-aspartate (NMDA) receptors and other potential mechanisms, ketamine may regulate neuronal excitability, reduce excessive synchronized neural activity, and counteract epileptic seizures. This positive impact on E/I balance reinforces the potential of ketamine as a promising drug for treating epilepsy, especially in patients who are insensitive to traditional anti-epileptic drugs. This review aims to consolidate the current understanding of ketamine's therapeutic role in epilepsy. It will focus its impact on neuronal excitability and synaptic plasticity, its neuroprotective qualities, and elucidate the drug's potential mechanisms of action in treating epilepsy. By scrutinizing ketamine's impact and mechanisms in various types of epilepsy, we aspire to contribute to a more comprehensive and holistic approach to epilepsy management.

Magnesium vs. sodium alginate as precursors of calcium alginate: Mechanical differences and advantages in the development of functional neuronal networks

Calcium alginate is one of the most widely employed matrices in regenerative medicine. A downside is its heterogeneity, due to the poorly controllable character of the gelation of sodium alginate (NaAlg), i.e. the commonly used alginate salt, with calcium. Here, we have used magnesium alginate (MgAlg) as an alternative precursor of calcium alginate. MgAlg coils, more compact and thus less entangled than those of NaAlg, allow for an easier diffusion of calcium ions, whereas Mg is exchanged with calcium more slowly than Na; this allows for the formation of a material (Ca(Mg)Alg) with a more reversible creep behaviour than Ca(Na)Alg, due to a more homogeneous - albeit lower - density of elastically active cross-links. We also show that Ca(Mg)Alg supports better than Ca(Na)Alg the network development and function of embedded (rat cortical) neurons: they show greater neurite extension and branching at 7 and 21 days (Tubb3 and Map2 immunofluorescence) and better neuronal network functional maturation / more robust and longer-lasting activity, probed by calcium imaging and microelectrode array electrophysiology. Overall, our results unveil the potential of MgAlg as bioactive biomaterial for enabling the formation of functional neuron-based tissue analogues.

Standardizing a method for functional assessment of neural networks in brain organoids

During the last decade brain organoids have emerged as an attractive model system, allowing stem cells to be differentiated into complex 3D models, recapitulating many aspects of human brain development. Whilst many studies have analysed anatomical and cytoarchitectural characteristics of organoids, their functional characterisation has been limited, and highly variable between studies. Standardised, consistent methods for recording functional activity are critical to providing a functional understanding of neuronal networks at the synaptic and network level that can yield useful information about functional network phenotypes in disease and healthy states. In this study we outline a detailed methodology for calcium imaging and Multi-Electrode Array (MEA) recordings in brain organoids. To illustrate the utility of these functional interrogation techniques in uncovering induced differences in neural network activity we applied various stimulating media protocols. We demonstrate overlapping information from the two modalities, with comparable numbers of active cells in the four treatment groups and an increase in synchronous behaviour in BrainPhys treated groups. Further development of analysis pipelines to reveal network level changes in brain organoids will enrich our understanding of network formation and perturbation in these structures, and aid in the future development of drugs that target neurological disorders at the network level.

The Role of Magnesium in Parkinson's Disease: Status Quo and Implications for Future Research

Neurodegenerative diseases represent an increasing economic, social, and, above all, medical burden worldwide. The second most prevalent disease in this category is Parkinson's disease, surpassed only by Alzheimer's. It is a treatable but still incurable systemic disease with a pathogenesis that has not yet been elucidated. Several theories are currently being developed to explain the causes and progression of Parkinson's disease. Magnesium is one of the essential macronutrients and is absolutely necessary for life as we know it. The magnesium cation performs several important functions in the cell in the context of energetic metabolism, substrate metabolism, cell signalling, and the regulation of the homeostasis of other ions. Several of these cellular processes have been simultaneously described as being disrupted in the development and progression of Parkinson's disease. The relationship between magnesium homeostasis and the pathogenesis of Parkinson's disease has received little scientific attention to date. The aim of this review is to summarise and critically evaluate the current state of knowledge on the possible role of magnesium in the pathogenesis of Parkinson's disease and to outline possible future directions for research in this area.

Magnesium and the Hallmarks of Aging

Magnesium is an essential ion in the human body that regulates numerous physiological and pathological processes. Magnesium deficiency is very common in old age. Age-related chronic diseases and the aging process itself are frequently associated with low-grade chronic inflammation, called 'inflammaging'. Because chronic magnesium insufficiency has been linked to excessive generation of inflammatory markers and free radicals, inducing a chronic inflammatory state, we formerly hypothesized that magnesium inadequacy may be considered among the intermediaries helping us explain the link between inflammaging and aging-associated diseases. We show in this review evidence of the relationship of magnesium with all the hallmarks of aging (genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, disabled autophagy, dysbiosis, and chronic inflammation), which may positively affect the human healthspan. It is feasible to hypothesize that maintaining an optimal balance of magnesium during one's life course may turn out to be a safe and economical strategy contributing to the promotion of healthy aging. Future well-designed studies are necessary to further explore this hypothesis.

Magnesium (Mg2+): Essential Mineral for Neuronal Health: From Cellular Biochemistry to Cognitive Health and Behavior Regulation

Magnesium (Mg2+) is a crucial mineral involved in numerous cellular processes critical for neuronal health and function. This review explores the multifaceted roles of Mg2+, from its biochemical interactions at the cellular level to its impact on cognitive health and behavioral regulation. Mg2+ acts as a cofactor for over 300 enzymatic reactions, including those involved in ATP synthesis, nucleic acid stability, and neurotransmitter release. It regulates ion channels, modulates synaptic plasticity, and maintains the structural integrity of cell membranes, which are essential for proper neuronal signaling and synaptic transmission. Recent studies have highlighted the significance of Mg2+ in neuroprotection, showing its ability to attenuate oxidative stress, reduce inflammation, and mitigate excitotoxicity, thereby safeguarding neuronal health. Furthermore, Mg2+ deficiency has been linked to a range of neuropsychiatric disorders, including depression, anxiety, and cognitive decline. Supplementation with Mg2+, particularly in the form of bioavailable compounds such as Magnesium-L-Threonate (MgLT), Magnesium-Acetyl-Taurate (MgAT), and other Magnesium salts, has shown some promising results in enhancing synaptic density, improving memory function, and alleviating symptoms of mental health disorders. This review highlights significant current findings on the cellular mechanisms by which Mg2+ exerts its neuroprotective effects and evaluates clinical and preclinical evidence supporting its therapeutic potential. By elucidating the comprehensive role of Mg2+ in neuronal health, this review aims to underscore the importance of maintaining optimal Mg2+ levels for cognitive function and behavioral regulation, advocating for further research into Mg2+ supplementation as a viable intervention for neuropsychiatric and neurodegenerative conditions.

Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration

Magnesium (Mg) is involved in the regulation of metabolism and in the maintenance of the homeostasis of all the tissues, including the brain, where it harmonizes nerve signal transmission and preserves the integrity of the blood-brain barrier. Mg deficiency contributes to systemic low-grade inflammation, the common denominator of most diseases. In particular, neuroinflammation is the hallmark of neurodegenerative disorders. Starting from a rapid overview on the role of magnesium in the brain, this narrative review provides evidences linking the derangement of magnesium balance with multiple sclerosis, Alzheimer's, and Parkinson's diseases.

Co-exposure of melamine and cyanuric acid as a risk factor for oxidative stress and energy metabolism: Adverse effects on hippocampal neuronal and synaptic function induced by excessive ROS production

Melamine (MEL) and cyanuric acid (CA) alone have relatively low toxicity, but together they may cause serious damage to multiple organs, including the central nervous system, however, the underlying mechanism is unknown. This study aimed to determine and compare the neurotoxic effects of MEL (20 μg/mL), CA (20 μg/mL) and their combination (10 μg/mL MEL and 10 μg/mL CA) on cultured hippocampal neurons. The cell viability, apoptosis, anti-oxidative and energy metabolic indices were detected following 24 h of incubations. The miniature excitatory postsynaptic currents (mEPSCs), miniature inhibitory postsynaptic currents (mIPSCs) and synaptic plasticity in the hippocampal CA1 neurons were recorded. Moreover, ROS scavenger NAC was co-infused to investigate the potential mechanism. We found the complex of MEL and CA but not their alone caused severe cell death and disturbed energy production through activation caspase-3-mediated apoptosis. Meanwhile, the combination significantly reduced the amplitude, decay time and frequency of mEPSCs but not mIPSCs, indicating the pre- and post-synaptic inhibitory actions on neuronal activity. Paired-pulsed ratio (PPR) and long-term potentiation (LTP) at the Schaffer collateral-CA1 synapses were critically depressed. However, the co-application of NAC could effectively mitigate the cellular apoptosis, energy metabolism dysfunction and the impairments in neuronal and synaptic function. Our findings provide the first evidence that the combination of MEL and CA can exert more prominently neurotoxic effects than their alone and certify that one of the potential mechanisms for neuronal and synaptic dysfunction is the ROS-mediated signaling pathway.

Magnesium and Zinc Oxide Nanoparticles from Datura alba Improve Cognitive Impairment and Blood Brain Barrier Leakage

Epilepsy is a neurological disorder involving persistent spontaneous seizures and uncontrolled neuronal excitability that leads to cognitive impairments and blood–brain barrier (BBB) disruption. Currently available antiepileptic drugs present side effects and researchers are trying to discover new agents with properties to overcome these drawbacks. The aim was to synthesize magnesium oxide (MgO) and zinc oxide (ZnO) nanoparticles from Datura alba fresh leaf extracts and evaluate their anti-epileptic potential in mice kindling or a repetitive seizures model. The phytoassisted synthesized nanoparticles were characterized using spectroscopy; FT-IR, XRD, SEM, and EDX. Analysis of the NPs confirmed the crystalline pleomorphic shape using the salts of both zinc and magnesium possibly stabilized, functionalized and reduced by bioactive molecules present in plant extract. By using several characterization techniques, NPs were confirmed. UV-Vis spectroscopy of biologically produced ZnO and MgO revealed distinctive peaks at 380 nm and 242 nm, respectively. Our findings categorically demonstrated the reductive role of biomolecules in the formation of ZnO and MgO NPs. The mice kindling model was induced using seven injections of Pentylenetetrazole (PTZ, 40 mg/kg, i.p) for 15 days alternatively. The results showed that mice post-treated with either ZnO or MgO nanoparticles (10 mg/kg, i.p) significantly improved in respect of behavior and memory as confirmed in the Morris water maze (MWM), open field (OF), novel object recognition (NOR) test compared with PTZ treated mice. Furthermore, the ZnO and MgO nanoparticle treatment also maintained the integrity of the BBB, reducing the leakage, as confirmed by Evans blue dye (EBD) compared with PTZ treated mice only. In summary, the current finding demonstrates that green synthesized ZnO and MgO nanoparticles have neuroprotective, ant-epileptic potential, molecular mechanisms, and clinical implications need to be further explored.

Magnesium-Encapsulated Injectable Hydrogel and 3D-Engineered Polycaprolactone Conduit Facilitate Peripheral Nerve Regeneration

Peripheral nerve injury is a challenging orthopedic condition that can be treated by autograft transplantation, a gold standard treatment in the current clinical setting. Nevertheless, limited availability of autografts and potential morbidities in donors hampers its widespread application. Bioactive scaffold-based tissue engineering is a promising strategy to promote nerve regeneration. Additionally, magnesium (Mg) ions enhance nerve regeneration; however, an effectively controlled delivery vehicle is necessary to optimize their in vivo therapeutic effects. Herein, a bisphosphonate-based injectable hydrogel exhibiting sustained Mg2+ delivery for peripheral nerve regeneration is developed. It is observed that Mg2+ promoted neurite outgrowth in a concentration-dependent manner by activating the PI3K/Akt signaling pathway and Sema5b. Moreover, implantation of polycaprolactone (PCL) conduits filled with Mg2+ -releasing hydrogel in 10 mm nerve defects in rats significantly enhanced axon regeneration and remyelination at 12 weeks post-operation compared to the controls (blank conduits or conduits filled with Mg2+ -absent hydrogel). Functional recovery analysis reveals enhanced reinnervation in the animals treated with the Mg2+ -releasing hydrogel compared to that in the control groups. In summary, the Mg2+ -releasing hydrogel combined with the 3D-engineered PCL conduit promotes peripheral nerve regeneration and functional recovery. Thus, a new strategy to facilitate the repair of challenging peripheral nerve injuries is proposed.

Roles of N-Methyl-D-Aspartate Receptors (NMDARs) in Epilepsy

Epilepsy is one of the most common neurological disorders characterized by recurrent seizures. The mechanism of epilepsy remains unclear and previous studies suggest that N-methyl-D-aspartate receptors (NMDARs) play an important role in abnormal discharges, nerve conduction, neuron injury and inflammation, thereby they may participate in epileptogenesis. NMDARs belong to a family of ionotropic glutamate receptors that play essential roles in excitatory neurotransmission and synaptic plasticity in the mammalian CNS. Despite numerous studies focusing on the role of NMDAR in epilepsy, the relationship appeared to be elusive. In this article, we reviewed the regulation of NMDAR and possible mechanisms of NMDAR in epilepsy and in respect of onset, development, and treatment, trying to provide more evidence for future studies.

Glutamatergic system components as potential biomarkers and therapeutic targets in cancer in non-neural organs

Glutamate is one of the most abundant amino acids in the blood. Besides its role as a neurotransmitter in the brain, it is a key substrate in several metabolic pathways and a primary messenger that acts through its receptors outside the central nervous system (CNS). The two main types of glutamate receptors, ionotropic and metabotropic, are well characterized in CNS and have been recently analyzed for their roles in non-neural organs. Glutamate receptor expression may be particularly important for tumor growth in organs with high concentrations of glutamate and might also influence the propensity of such tumors to set metastases in glutamate-rich organs, such as the liver. The study of glutamate transporters has also acquired relevance in the physiology and pathologies outside the CNS, especially in the field of cancer research. In this review, we address the recent findings about the expression of glutamatergic system components, such as receptors and transporters, their role in the physiology and pathology of cancer in non-neural organs, and their possible use as biomarkers and therapeutic targets.

Nutritional Supplements for the Treatment of Neuropathic Pain

Neuropathic pain affects 7-10% of the population and is often ineffectively and incompletely treated. Although the gold standard for treatment of neuropathic pain includes tricyclic antidepressants (TCAs), serotonin-noradrenaline reuptake inhibitors, and anticonvulsants, patients suffering from neuropathic pain are increasingly turning to nonpharmacologic treatments, including nutritional supplements for analgesia. So-called "nutraceuticals" have garnered significant interest among patients seeking to self-treat their neuropathic pain with readily available supplements. The supplements most often used by patients include vitamins such as vitamin B and vitamin D, trace minerals zinc and magnesium, and herbal remedies such as curcumin and St. John's Wort. However, evidence surrounding the efficacy and mechanisms of these supplements in neuropathic pain is limited, and the scientific literature consists primarily of preclinical animal models, case studies, and small randomized controlled trials (RCTs). Further exploration into large randomized controlled trials is needed to fully inform patients and physicians on the utility of these supplements in neuropathic pain. In this review, we explore the basis behind using several nutritional supplements commonly used by patients with neuropathic pain seen in rheumatology clinics.

Possible prospects for using modern magnesium preparations for increasing stress resistance during COVID-19 pandemic

Introduction: The relevance of the issue of increasing stress resistance is due to a significant deterioration in the mental health of the population caused by the special conditions of the disease control and prevention during the COVID-19 pandemic. Recently, the decisive role in the severity of clinico-physiological manifestations of maladjustment to stress is assigned to magnesium ions.

The aim of the work was to study the magnesium importance in the body coping mechanisms under stress for the pathogenetic substantiation of the magnesium correction in an unfavorable situation of disease control and prevention during the COVID-19 pandemic.

Materials and methods: The theoretical basis of this scientific and analytical review was an analysis of modern Russian and foreign literature data posted on the electronic portals MEDLINE, PubMed-NCBI, Scientific Electronic Library eLIBRARY.RU, Google Academy, and CyberLeninka.

Results and discussion: It was shown that the total magnesium level in the body plays the indicator role of the body functional reserves. Acute and chronic stresses significantly increase the magnesium consumption and cause a decrease in its body content. Magnesium deficiency is one of the main pathogenetic mechanisms of reducing stress resistance and adaptive body reserves. Arising during the COVID-19 pandemic, increased nervous and emotional tension, the lack of emotional comfort and balance can lead to the onset or deterioration of magnesium deficiency, which manifests itself in mental burnout and depletion of adaptive capacities. The inability to synthesize magnesium in the body necessitates including foodstuffs high in magnesium in the population diet during this period. The appointment of magnesium preparations is pathogenetically justified with moderate and severe magnesium deficiency. This therapy should take into account the major concomitant diseases, severity of magnesium deficiency, and a patient’s age.

Conclusion: magnesium correction, carried out during the COVID-19 pandemic, will contribute to increasing stress resistance, preventing mental diseases and improving the population’s life quality.

Possibility of magnesium supplementation for supportive treatment in patients with COVID-19

Magnesium as an enzymatic activator is essential for various physiological functions such as cell cycle, metabolic regulation, muscle contraction, and vasomotor tone. A growing body of evidence supports that magnesium supplementation (mainly magnesium sulfate and magnesium oxide) prevents or treats various types of disorders or diseases related to respiratory system, reproductive system, nervous system, digestive system, and cardiovascular system as well as kidney injury, diabetes and cancer. The ongoing pandemic coronavirus disease 19 (COVID-19) characterized by respiratory tract symptoms with different degrees of important organ and tissue damages has attracted global attention. Particularly, effective drugs are still lacking in the COVID-19 therapy. In this review, we find and summarize the effectiveness of magnesium supplementation on the disorders or diseases, and provide a reference to the possibility of magnesium supplementation for supportive treatment in patients with COVID-19.

Headaches and Magnesium: Mechanisms, Bioavailability, Therapeutic Efficacy and Potential Advantage of Magnesium Pidolate

Magnesium deficiency may occur for several reasons, such as inadequate intake or increased gastrointestinal or renal loss. A large body of literature suggests a relationship between magnesium deficiency and mild and moderate tension-type headaches and migraines. A number of double-blind randomized placebo-controlled trials have shown that magnesium is efficacious in relieving headaches and have led to the recommendation of oral magnesium for headache relief in several national and international guidelines. Among several magnesium salts available to treat magnesium deficiency, magnesium pidolate may have high bioavailability and good penetration at the intracellular level. Here, we discuss the cellular and molecular effects of magnesium deficiency in the brain and the clinical evidence supporting the use of magnesium for the treatment of headaches and migraines.