Search Results (3,229)

This paper studies global asymptotic stability of Cohen–Grossberg neural networks involving discrete time delays in the neuron states and neutral delays in the time derivatives of the neuron states. An appropriate Lyapunov functional, which is defined by the linear combination of three Lyapunov functionals of the quadratic forms, is constructed to determine new criteria for global asymptotic stability of neutral-type neural networks with discrete delay parameters. The proposed stability conditions are established through a set of algebraic inequalities that utilize key matrix properties and parameters of system functions. These criteria are proved to be independent of delay components, and they can be tested by checking some algebraic inequalities. A numerical example is studied to illustrate the efficiency aspects of the derived stability conditions. Full article

Chronic pain continues to be a major global health burden and is frequently refractory to conventional pharmacologic and conservative therapies. Spinal cord stimulation (SCS) has emerged as an important neuromodulatory treatment for selected patients with chronic neuropathic and mixed pain syndromes. Since its introduction in the 1960s, SCS has evolved from paresthesia-based tonic stimulation into more adaptive and personalized neuromodulation. This review summarizes the current evidence regarding the mechanisms, clinical applications, technological advances, and future directions of SCS therapy. Mechanistically, SCS modulates nociceptive transmission through dorsal column and dorsal horn pathways, inhibitory neurotransmitter systems, wide-dynamic-range neuronal activity, and supraspinal pain-processing networks. Technological advances have expanded available stimulation paradigms, including burst stimulation, high-frequency stimulation, closed-loop evoked compound action potential-controlled systems, and differential target multiplexed stimulation. These approaches aim to improve analgesic durability, reduce the burden of paresthesia, and address mechanisms such as neuroinflammation and neural habituation. Clinically, SCS is used for conditions including failed back surgery syndrome, complex regional pain syndrome, painful diabetic neuropathy, ischemic limb pain, and emerging non-traditional pain states. However, outcomes remain variable and are influenced by psychological readiness, pain phenotype, anatomic factors, trial response, neurophysiologic markers, and patient engagement. Complications such as lead migration, infection, implantable pulse generator malfunction, and loss of efficacy remain important considerations. Future progress in SCS will likely depend on artificial intelligence, remote monitoring, biomarker-guided programming, and integration with multidisciplinary chronic pain care. Full article

Leucine-rich repeat kinase 2 (LRRK2) has emerged as a central molecular node linking genetic risk, membrane trafficking, lysosomal homeostasis, and immune signalling in Parkinson’s disease (PD). Rather than functioning as a conventional protein kinase, LRRK2 operates as a conformationally regulated, Rab-directed signalling machine whose activity is governed by long-range interdomain communication, membrane recruitment, and cooperative interactions with small GTPases. Converging advances in cryo-electron microscopy, quantitative phosphoproteomics, and human genetics indicate that pathogenic mutations, lysosomal stress, and pharmacological inhibitors do not simply alter catalytic output, but reshape the conformational landscape of LRRK2, biasing it toward distinct structural states with divergent cellular consequences. A defining feature of this system is the selective phosphorylation of Rab GTPases at low stoichiometry—most prominently Rab8 and Rab10—yet with disproportionate functional impact on vesicle trafficking, ciliogenesis, autophagy, and organelle positioning. The identification of Rab-directed phosphatases, particularly PPM1H, further establishes that LRRK2 signalling is governed by a dynamically balanced kinase–phosphatase circuit operating in space and time. These observations, together with emerging evidence linking LRRK2 activation to lysosomal damage and immune pathways, support a unifying hypothesis: PD-associated LRRK2 dysfunction arises from maladaptive stabilization of specific conformational and spatial states within a membrane-responsive signalling network, leading to persistent misregulation of Rab-dependent trafficking and organelle homeostasis, rather than from kinase hyperactivity alone. In this review, we integrate structural, biochemical, and cellular evidence to advance this framework and discuss its implications for disease mechanisms and therapy. We highlight key unresolved challenges—including conformation-selective drug targeting, spatial control of Rab phosphorylation, and context-dependent immune–neuronal crosstalk—and propose that restoring physiological regulation of LRRK2, rather than simply inhibiting its activity, will be essential for achieving mechanism-based disease modification in Parkinson’s disease. Full article

Cold hypersensitivity in hands and feet (CHHF) affects 20–52% of East Asian populations, is more prevalent in women, and is managed with vasodilators in Western medicine or herbal therapies in traditional East Asian medicine. This study was conducted to compare the pharmacological characteristics of two heat-clearing (HCHs, Scutellariae Radix and Coptidis Rhizoma) and two blood-tonifying (BTHs, Angelicae Sinensis Radix and Paeoniae Radix Alba) herbs used for CHHF. Candidate herbs were selected based on herbology classifications, PubMed searches, and the Korean Medicine Clinical Practice Guideline for CHHF. A total of 61 active compounds and 323 corresponding protein targets with CHHF were retrieved from the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP), standardized via UniProt, and intersected with CHHF-related genes from GeneCards. Protein–protein interaction networks were constructed, core targets identified, and functional enrichment analyses performed using Reactome databases. A total of 166 herb–CHHF common targets were identified, including 24 shared across all four herbs. HCHs were primarily enriched in hemostasis-, immune-, and signaling-related pathways, whereas BTHs were associated with immune regulation, metabolism, and neuronal modulation. Notably, Scutellariae Radix and Paeoniae Radix Alba showed substantial overlap in enriched pathways. These findings suggest that HCHs and BTHs may be associated with distinct yet potentially relevant molecular mechanisms in CHHF. However, because the present analysis was conducted at the single-herb level, these findings cannot be directly generalized to the clinical use of multi-herb formulas and should be interpreted as hypothesis-generating. Full article

Neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (PD) develop over decades, yet their earliest pathogenic drivers remain poorly understood. Epidemiological and experimental animal studies suggest that disturbances in oral sensorimotor regulation, particularly within trigeminal proprioceptive pathways, may contribute to neural dysfunction long before clinical symptoms emerge. The mesencephalic trigeminal nucleus (MesV), the only primary sensory neuron population located entirely within the central nervous system (CNS), links oral proprioception with brainstem and forebrain networks. Chronic occlusal mismatch, impaired mastication, sleep bruxism, and sleep-disordered breathing may generate persistent sensorimotor prediction errors that destabilize MesV-centered circuits and subsequently recruit the locus coeruleus (LC), the brain’s principal noradrenergic stress nucleus. This review proposes an oral–brain axis model in which chronic MesV-related prediction error signaling engages LC-dependent stress systems, leading to neuroimmune activation, locus coeruleus–asparagine endopeptidase (LC-AEP) pathway engagement, and downstream proteinopathic processes. Sustained LC activity may facilitate microglial priming, reactive astrocytosis, and neuroinflammatory signaling, creating conditions that favor LC-AEP pathway activation and downstream tau pathology. Epidemiological studies associate tooth loss, reduced occlusal support, and impaired mastication with increased dementia risk, while experimental models of prodromal PD demonstrate early trigeminal sensory-processing abnormalities preceding motor symptoms. Together, these findings support the hypothesis that chronic disturbances in oral sensorimotor homeostasis may increase neurodegenerative vulnerability. This framework identifies potential biomarkers and preventive targets, suggesting that modulation of oral function and neuroimmune pathways may help reduce neurodegenerative risk before irreversible neuronal loss occurs. Full article

Background/Objectives: Cerebral ischemia–reperfusion injury (CIRI) poses therapeutic challenges because of oxidative stress, blood–brain barrier disruption, and neuronal apoptosis, limiting current treatments. Paeoniflorin (PF) from Paeonia lactiflora has neuroprotective potential, but its multi-target mechanisms remain unclear. This study investigated the role and mechanisms of PF in CIRI, focusing on neuron–endothelial crosstalk. Methods: Oxygen–glucose deprivation/reoxygenation (OGD/R) models were established using SH-SY5Y (human neuroblastoma) and HCMEC/D3 cells (human cerebral microvascular endothelial). Network pharmacology was used to predict potential PF targets and pathways. RNA sequencing, molecular docking, and molecular dynamics simulation were performed to screen and evaluate PF binding characteristics with key targets, and MTT, flow cytometry, Western blotting, and co-cultures were employed to detect paracrine interactions. Results: Network pharmacology and transcriptomics identified VEGF/PI3K-AKT/mTOR pathway enrichment. Molecular docking confirmed stable PF binding to VEGF-A (−8.4 kcal/mol), AKT (−5.5 kcal/mol), and mTOR (−9.6 kcal/mol). PF (10–80 μM) showed no cytotoxicity and reduced OGD/R injury in a concentration-dependent manner (maximal at 40 μM). PF activated VEGF/PI3K-AKT/mTOR signaling, reducing apoptosis by 57% (SH-SY5Y) and 33% (HCMEC/D3); PI3K inhibitor LY294002 abolished these effects. PF-treated HCMEC/D3-conditioned media enhanced OGD/R neuronal viability, verifying paracrine crosstalk. Conclusions: PF alleviated CIRI by directly protecting neurons and indirectly modulating neuron–endothelial crosstalk through VEGF/PI3K-AKT/mTOR activation, supporting its multi-target therapeutic potential. Full article

Parkinson’s disease (PD) is characterized by progressive dopaminergic degeneration and maladaptive motor cortical plasticity. However, the cellular pathways underlying cortical surface activity in the primary motor cortex (M1) remain unclear, despite serving as a potential target for electrotherapy. We investigated the excitatory–inhibitory (E-I) balance and synaptic plasticity of superficial M1 circuits in a unilateral 6-hydroxydopamine (6-OHDA)-induced rat model of PD. Using extracellular local field potential and whole-cell patch recordings from the contralateral and ipsilateral M1 hemispheres of hemi-parkinsonian rats, we observed a significantly elevated field excitatory postsynaptic potential (fEPSP) input–output function but unchanged intrinsic neuronal excitability in the M1 superficial layer. An altered relative contribution between alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)- and N-methyl-D-aspartate receptor (NMDAR)-mediated transmission was reflected by a significantly increased AMPA/NMDA ratio. Markedly reduced inhibitory synaptic tone was also evidenced by the decreased amplitude and frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), supporting an E-I imbalance favoring excitation in PD. Furthermore, group I metabotropic glutamate receptor (mGluR_1/5)-dependent long-term depression (LTD) was abolished in the ipsilateral PD hemisphere, whereas NMDAR-dependent LTD remained intact. In summary, dopamine depletion appears to enhance network excitation and disrupt mGluR_1/5-mediated control of M1 surface circuitry. Our findings identify altered cortical surface mGluR-dependent plasticity in the hemi-parkinsonian model; however, the relationship between these electrophysiological alterations and individual motor outcomes remains to be determined. Full article

Background/Objectives: Transcranial magnetic stimulation (TMS) initiates a cascade from intracranial electric-field exposure through neural recruitment and plasticity to distributed network responses. Neuronavigation improves the geometric reproducibility of delivery but does not guarantee equivalent cortical exposure or target engagement. This narrative review integrates these levels within an operational framework for precision TMS. Methods: Six domain-specific PubMed searches covering 1 January 1985 to 31 July 2026 were supplemented by Google Scholar and citation tracking. A documented rerun on 17 August 2026 yielded 6430 records (5617 unique after cross-query deduplication). Evidence was synthesized narratively; no quantitative synthesis or formal risk-of-bias assessment was performed. Results: Neuronavigation improves geometric precision by stabilizing target definition and coil pose, whereas individualized electric-field models estimate intracranial exposure. Neither establishes biological precision, which also depends on neuronal orientation, brain state, circuit architecture, medication, and behavior. Motor-system measures are not validated as universal biomarkers for nonmotor cortex, and no single validated biomarker captures TMS-induced plasticity. Convergent, controlled multimodal evidence may strengthen inference about target engagement; adaptive and closed-loop approaches remain experimental. Conclusions: Geometric delivery, modeled exposure, biological engagement, and durable functional or clinical benefit require separate validation. Spatial accuracy alone does not establish clinical value. Full article

This paper presents a comparative study of two approaches for solving second-order ordinary differential equations arising from the membrane theory of shells of revolution. The considered equations originate from the rotational symmetry of shell structures, which enables the reduction of the governing partial differential equations to a sequence of ordinary differential equations corresponding to individual circumferential harmonics. The study compares the classical Differential Transform Method (DTM) with Physics-Informed Neural Networks (PINNs). Both initial value and boundary value problems are investigated, including benchmark examples with known analytical solutions and a systematic analysis of the influence of PINN architecture on the solution accuracy. For the PINN approach, the effects of the number of collocation points, hidden layers, and neurons per layer on the approximation error and training time are examined. The results demonstrate that DTM provides an efficient framework for constructing analytical solutions of initial value problems with minimal computational cost. However, its application to boundary value problems requires the introduction of additional auxiliary parameters and the solution of supplementary nonlinear equations, considerably increasing the analytical complexity of the procedure. In contrast, PINNs achieve high accuracy for both initial and boundary value problems while naturally incorporating boundary conditions through the loss function. The presented results demonstrate how the exploitation of geometric symmetry, combined with modern scientific machine learning techniques, provides an effective computational framework for solving differential equations arising in shell mechanics. Full article

Background: Microtubules play a crucial role in neuronal structure and function, with their stability and dynamics regulated by posttranslational modifications (PTMs) such as polyglutamylation. In Alzheimer’s disease (AD), the microtubule-associated protein TAU becomes mislocalized into the somatodendritic compartment (‘TAU missorting’), dissociates from microtubules, aggregates into neurofibrillary tangles, and contributes to microtubule destabilization and neuronal death. Objectives and Methods: Here, we investigated the role of tubulin tyrosine ligase-like proteins (TTLLs) in TAU missorting and microtubule dysregulation using human-induced pluripotent stem cell (hiPSC)-derived cortical neurons treated with oligomeric amyloid-beta (oAβ) to replicate AD-like conditions. TTLL1, TTLL4, and TTLL6 were selectively knocked down (KD) to assess their impact on TAU missorting and microtubule stability. Fluorescence resonance energy transfer (FRET) microscopy was used to examine proximities between TAU and TTLL proteins. Results: We observed TAU missorting, increased tubulin polyglutamylation, decreased tubulin acetylation associated with microtubule destabilization, and synaptic declustering in oAβ-treated neurons. TTLL1 KD significantly reduced TAU missorting, tubulin polyglutamylation, and synaptic disintegration, while TTLL4 KD showed moderate effects, and TTLL6 KD restored microtubule acetylation. Importantly, TTLL KD did not impair neuritic networks, dendritic complexity, or neuronal activity. FRET microscopy in HEK293T cells revealed a close molecular proximity between TAU and TTLL1 consistent with a potential direct or complex-mediated association, but not with other TTLLs, suggesting a direct role of TTLL1 in TAU-mediated toxicity. Conclusions: Our findings identify TTLL1 as a promising therapeutic target for limiting TAU-associated cytoskeletal pathology in AD. These results support further development of pharmacological or genetic strategies targeting TTLL1 as a disease-modifying approach for AD and related tauopathies. Full article

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a severe manifestation of lupus marked by cognitive and mood disorders, yet the molecular mechanisms underlying hippocampal dysfunction remain poorly understood. To address this, we performed bulk RNA sequencing on hippocampal tissue from 17-week-old female MRL/Lpr mice and MRL^+/+ controls, followed by an integrative multi-layered analytical workflow. Differential gene expression analysis identified 223 significant differentially expressed genes, with a predominant downregulation of myelin-related transcripts. Gene set enrichment analysis confirmed coordinated suppression of oligodendrocyte differentiation, neuron ensheathment, and Wnt signaling programs. Weighted gene co-expression network analysis identified a disease-associated module enriched in myelination and glial developmental pathways, with hub genes spanning structural, transcriptional, and adhesion-related functions. Cell-type deconvolution revealed a selective reduction in mature oligodendrocytes, while oligodendrocyte precursor cells remained largely unaffected, consistent with impaired lineage maturation rather than global loss. RT-qPCR and Western blot validated the repression of key myelin-related genes and MBP protein in MRL/Lpr hippocampi. Collectively, these findings challenge an inflammation-centric interpretation of NPSLE hippocampal pathology, highlighting instead an additional contribution of impaired oligodendrocyte maturation. This transcriptomic resource establishes a molecular foundation for future mechanistic and histological investigations. Full article

Background: Population aging is driving a convergent rise in three disorders historically managed in isolation: cardiovascular disease, neurocognitive decline, and osteoporotic bone loss. Mechanistic data indicate that these systems are coupled through shared regulators of calcium trafficking, inflammation resolution, vascular integrity, and inflammaging. On this basis, a “Heart–Brain–Bone” axis has been proposed; it should be understood as an integrative conceptual framework that organizes evidence drawn from three separate studies, not as a validated physiological entity with agreed diagnostic criteria or demonstrated modifiability. Three lipid-soluble nutrients—long-chain omega-3 polyunsaturated fatty acids (EPA/DHA), vitamin D3 (cholecalciferol), and vitamin K2 (menaquinone-7 [MK-7])—act on overlapping nodes of this network. Methods: We performed a structured narrative review. PubMed/MEDLINE, Embase, the Cochrane Library, and Web of Science were searched from database inception to 25 June 2026 using predefined term blocks for each nutrient, each organ domain, and each candidate mechanism, and the search was updated on 7 August 2026. Records were screened against prespecified inclusion and exclusion criteria by two authors independently, with disagreements resolved by a third. The strength of evidence for each nutrient–organ relationship was graded with an explicitly defined four-level scheme ((−) to (+++)) applied separately to preclinical, observational, randomized and meta-analytic evidence. Results: Vitamin K2-dependent gamma-carboxylation of matrix Gla protein (MGP) and osteocalcin has been proposed to influence whether calcium is incorporated into the bone matrix or deposited in the arterial wall, offering a candidate mechanistic account of the “calcium paradox” associated with isolated vitamin D3 supplementation; EPA/DHA-derived specialized pro-resolving mediators may support resolution of endothelial and neuronal inflammation; and bone-, vascular- and brain-derived signals (osteocalcin, FGF23, the neurovascular unit) interconnect the three organs. These mechanisms are biologically plausible but remain insufficiently confirmed in humans. The clinical evidence is heterogeneous, formulation- and population-dependent, and comprises positive, neutral and null results: cardiovascular omega-3 trials are discordant (REDUCE-IT, which used icosapent ethyl [an EPA ethyl ester], positive; VITAL/STRENGTH/ASCEND null, predominantly in lower-risk or replete cohorts); cognitive trials are largely null or subgroup-dependent (MAPT, DO-HEALTH, VITAL); and MK-7 improves surrogate bone and calcification biomarkers and slowed coronary artery calcification in one recent randomized imaging trial (VitaK-CAC), whereas combined MK-7 plus vitamin D3 did not slow aortic valve or coronary calcification in AVADEC and MK-7 did not reduce bone loss in early menopausal women. Recognized safety signals include a dose-dependent increase in atrial fibrillation with high-dose omega-3, adverse skeletal effects of high-dose or bolus vitamin D, and clinically relevant interference of even low-dose MK-7 with vitamin K antagonist therapy. Conclusions: No adequately powered randomized trial has demonstrated that the combination of long-chain omega-3, vitamin D3 and MK-7 is superior to its individual components or to placebo for any clinical endpoint. The combined regimen is therefore mechanistically rational and hypothesis-generating rather than clinically established; benefit appears most plausible in individuals with elevated risk or demonstrable nutritional insufficiency, and least in replete, low-risk populations. Findings should be interpreted within a broader healthy-aging context that includes lifestyle and psychosocial factors. Adequately powered factorial randomized controlled trials stratified by baseline Omega-3 index, 25(OH)D and vitamin K status, with prespecified mechanistic biomarkers and hard endpoints, are required. Full article

Motor neurons form a highly specialized network composed of α-, β-, and γ-subtypes that coordinate skeletal muscle activity. Motor neuron diseases (MNDs), including amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), are characterized by the progressive degeneration of this network, resulting in motor dysfunction. Emerging evidence underscores the significant roles of long non-coding RNAs (lncRNAs) in motor neuron development and disease. However, only a few have been experimentally confirmed as true ceRNA regulators, highlighting the need to differentiate validated mechanisms from mere associations or predictions. This review summarizes the regulatory roles of lncRNA-associated ceRNA networks in motor neuron development, evaluates the evidence for their involvement in MNDs, and explores their potential impact on disease progression. It also addresses current challenges, knowledge gaps, and future research directions for understanding ceRNA-mediated mechanisms and developing therapeutic strategies for MNDs. Full article

The development and maintenance of the nervous system depend on a tightly regulated intracellular transport network in which kinesin superfamily (KIF) motor proteins drive microtubule-based delivery of synaptic vesicle precursors, organelles, mRNAs, and signaling components along axons and dendrites. Disruption of this machinery underlies a clinically heterogeneous spectrum of neurodevelopmental disorders (NDDs), including intellectual disability, epilepsy, autism spectrum disorder, microcephaly, malformations of cortical development, spasticity, and axonal neuropathy. Here, we synthesize current knowledge on how kinesin dysfunction shapes neurodevelopment. We outline the physiological roles of kinesins in neuronal polarity, organelle and mitochondrial positioning, synaptogenesis, and progenitor division, and survey principal disease-associated genes, including KIF1A, KIF5A, KIF7, KIF11, KIF2A, KIF5C, and emerging members such as KIF14, KIF15, and KIF16B. We detail how distinct pathogenic mechanisms, such as loss of motility, impaired cargo coupling, motor hyperactivity, mitotic spindle defects, and disrupted ciliary signaling, converge on shared cellular endpoints, and how tubulin isotypes and posttranslational modifications further modulate motor output. In this review, we discuss translational implications, including variant-resolved diagnosis and precision strategies to restore transport, dampen pathological hyperactivity, or stabilize the microtubule track. Collectively, these advances reframe kinesinopathies as mechanistically stratified disorders of neuronal transport. Full article

Dementia with Lewy bodies (DLB) is increasingly conceptualised not merely as a disorder of neuronal death but as a primary synaptopathy in which the functional collapse of synaptic transmission and plasticity precedes, and predicts, neurodegeneration and clinical decline. Two genetic determinants dominate the heritable risk architecture of DLB: the α-synuclein gene SNCA, in which both copy-number variation and missense mutations exert dose- and conformation-dependent effects, and GBA1, encoding the lysosomal hydrolase glucocerebrosidase (GCase), the single most influential genetic risk factor for the disease. Here we synthesise evidence that these loci converge on a shared pathogenic endpoint—the impairment of activity-dependent synaptic plasticity. We argue that GBA1 loss-of-function and the resulting accumulation of glucosylceramide stabilise specific neurotoxic α-synuclein proteoforms, including soluble oligomers and self-templating conformational strains bearing defined post-translational modifications. These proteoforms are trafficked to, and enriched within, presynaptic terminals, where they disrupt SNARE-complex assembly and synaptic-vesicle dynamics, while postsynaptically they perturb NMDA and AMPA receptor trafficking, dysregulate dendritic calcium, and compromise synaptic mitochondrial bioenergetics. The net consequence is a metaplastic shift away from long-term potentiation (LTP) and toward aberrant long-term depression (LTD), a signature of synaptic failure detectable before frank pathology. We map these molecular events onto disease-relevant circuits—particularly the cholinergic basal forebrain and hippocampal–cortical and thalamocortical networks—and relate them to the defining neuropsychiatric features of DLB, including cognitive fluctuations and recurrent visual hallucinations. Finally, we evaluate emerging therapeutic strategies that target the GBA1–α-synuclein axis and that aim to restore synaptic plasticity directly. Positioning DLB within the framework of genetically determined plasticity deficits clarifies its kinship with other neuropsychiatric disorders and identifies the synapse as the most tractable node for early, disease-modifying intervention. We further examine how GBA1 allele severity and zygosity grade the phenotype, which genetic and environmental factors modify penetrance in carriers, and what distinguishes this synaptopathy from those driven by PSEN1/PSEN2, MAPT, or HTT, and we summarise the therapeutic pipeline—including enzyme augmentation and adeno-associated viral GBA1 gene therapy—that targets it. Full article