Search Results (842)

Human induced pluripotent stem cell-derived cardiomyocytes (iCMs) provide a powerful platform for investigating cardiac biology. However, structural, metabolic, and electrophysiological immaturity of iCMs limits their capacity to model adult cardiomyocytes. Currently, no universally accepted criteria or protocols for effective iCMs maturation exist. This study aimed to identify practical culture conditions that promote iCMs maturation, thereby generating more physiologically relevant in vitro cardiac models. We evaluated the effects of short- and long-term culture in media supplemented with various stimulatory compounds under 2D conditions, focusing on intracellular content and localization of slow skeletal troponin I (ssTnI) and cardiac troponin I (cTnI) isoforms. Our findings demonstrate that the multicomponent metabolic maturation medium (MM-1) effectively enhances the transition toward a more mature iCM phenotype, as evidenced by increased cTnI expression and formation of cross-striated myofibrils. iCMs cultured in MM-1 more closely resemble adult cardiomyocytes and are compatible with high-resolution single-cell techniques such as electron microscopy and patch-clamp electrophysiology. This work provides a practical and scalable approach for advancing the maturation of iPSC-derived cardiac models, with applications in disease modeling and drug screening. Full article

Magnetocardiography (MCG) provides a non-invasive, contactless technique for evaluating the magnetic fields generated by cardiac electrical activity, offering unique spatial insights into cardiac electrophysiology. However, conventional MCG systems depend on superconducting quantum interference devices that require cryogenic cooling and magnetic shielded environments, posing considerable impediments to widespread clinical adoption. In this study, we present a novel MCG system utilizing a high-sensitivity, wide-dynamic-range magnetoresistive sensor array operating at room temperature. To mitigate environmental interference, identical sensors were deployed as reference channels, enabling adaptive noise cancellation (ANC) without the need for traditional magnetic shielding. MCG recordings were obtained from 40 healthy participants, with signals processed using ANC, R-peak-synchronized averaging, and Bayesian spatial signal separation. This approach enabled the reliable detection of key cardiac components, including P, QRS, and T waves, from the unshielded MCG recordings. Our findings underscore the feasibility of a cost-effective, portable MCG system suitable for clinical settings, presenting new opportunities for noninvasive cardiac diagnostics and monitoring. Full article

Microglia, as the immune guardians of the central nervous system (CNS), have the ability to maintain neural homeostasis, respond to environmental changes, and remodel the synaptic landscape. However, persistent microglial activation can lead to chronic neuroinflammation, which can alter neuronal signaling pathways, resulting in accelerated cognitive decline. Phosphoinositol 3-kinase (PI3K) has emerged as a critical driver, connecting inflammation to neurodegeneration, serving as the nexus of numerous intracellular processes that govern microglial activation. This review focuses on the relationship between PI3K signaling and microglial activation, which might lead to cognitive impairment, inflammation, or even neurodegeneration. The review delves into the components of the PI3K signaling cascade, isoforms, and receptors of PI3K, as well as the downstream effects of PI3K signaling, including its effectors such as protein kinase B (Akt) and mammalian target of rapamycin (mTOR) and the negative regulator phosphatase and tensin homolog (PTEN). Experiments have shown that the overproduction of certain cytokines, coupled with abnormal oxidative stress, is a consequence of poor PI3K regulation, resulting in excessive synapse pruning and, consequently, impacting learning and memory functions. The review also highlights the implications of autonomously activated microglia exhibiting M1/M2 polarization driven by PI3K on hippocampal, cortical, and subcortical circuits. Conclusions from behavioral studies, electrophysiology, and neuroimaging linking cognitive performance and PI3K activity were evaluated, along with new approaches to therapy using selective inhibitors or gene editing. The review concludes by highlighting important knowledge gaps, including the specific effects of different isoforms, the risks associated with long-term pathway modulation, and the limitations of translational potential, underscoring the crucial role of PI3K in mitigating cognitive impairment driven by neuroinflammation. Full article

Neuroactive steroids (NAS) have long been recognized for their hypnotic and anesthetic properties in both clinical and preclinical settings. While sex differences in NAS sensitivity are acknowledged, the underlying mechanisms remain poorly understood. Here, we examined sex-specific responses to an endogenous NAS epipregnanolone (EpiP) in wild-type mice using behavioral assessment of hypnosis (loss of righting reflex, LORR) and in vivo electrophysiological recordings. Specifically, local field potentials (LFPs) were recorded from the central medial thalamus (CMT) and electroencephalogram (EEG) signals were recorded from the barrel cortex. We found that EpiP-induced LORR exhibited clear sex differences, with females showing increased sensitivity. Spectral power analysis and thalamocortical (TC) and corticocortical (CC) phase synchronization further supported enhanced hypnotic susceptibility in female mice. Our findings reveal characteristic sex-dependent effects of EpiP on the synchronized electrical activity in both thalamus and cortex. These results support renewed exploration of endogenous NAS as clinically relevant anesthetic agents. Full article

The assessment of hearing in children is important, as hearing deficits can impair child development. The Auditory Steady-State Response (ASSR) is an electrophysiological technique that is able to simultaneously evaluate both ears at four frequencies, making it advantageous for testing children where the test time needs to be as short as possible. The objective of this work was to perform a literature review on the effectiveness of ASSR to gauge hearing thresholds in babies, infants, and children, examining its ability to distinguish mild hearing loss from normal cases. This review used PubMed, Web of Science, and Scopus databases from 2014 to 2024. A total of 1226 articles were identified, although only 16 met the previously established inclusion criteria. It was found that ASSR is a reliable diagnostic tool for babies, infants, and children. Recent work appears better able to distinguish mild hearing loss from normal hearing. One unresolved aspect that needs additional attention is the effectiveness of using bone-conducted stimuli. Full article

Introduction: Substance use disorders (SUDs) pose a significant public health challenge, with current treatments often exhibiting limited effectiveness and high relapse rates. Transcranial direct current stimulation (tDCS), a noninvasive neuromodulation technique that delivers low-intensity direct current via scalp electrodes, has shown promise in various psychiatric and neurological conditions. In SUDs, tDCS may help to modulate key neurocircuits involved in craving, executive control, and reward processing, potentially mitigating compulsive drug use. However, the precise neurobiological mechanisms by which tDCS exerts its therapeutic effects in SUDs remain only partly understood. This review addresses that gap by synthesizing evidence from clinical studies that used neuroimaging (fMRI, fNIRS, EEG) and blood-based biomarkers to elucidate tDCS’s mechanisms in treating SUDs. Methods: A targeted literature search identified articles published between 2008 and 2024 investigating tDCS interventions in alcohol, nicotine, opioid, and stimulant use disorders, focusing specifically on physiological and neurobiological assessments rather than purely behavioral outcomes. Studies were included if they employed either neuroimaging (fMRI, fNIRS, EEG) or blood tests (neurotrophic and neuroinflammatory markers) to investigate changes induced by single- or multi-session tDCS. Two reviewers screened titles/abstracts, conducted full-text assessments, and extracted key data on participant characteristics, tDCS protocols, neurobiological measures, and clinical outcomes. Results: Twenty-seven studies met the inclusion criteria. Across fMRI studies, tDCS—especially targeting the dorsolateral prefrontal cortex—consistently modulated large-scale network activity and connectivity in the default mode, salience, and executive control networks. Many of these changes correlated with subjective craving, attentional bias, or extended time to relapse. EEG-based investigations found that tDCS can alter event-related potentials (e.g., P3, N2, LPP) linked to inhibitory control and salience processing, often preceding or accompanying changes in craving. One fNIRS study revealed enhanced connectivity in prefrontal regions under active tDCS. At the same time, two blood-based investigations reported the partial normalization of neurotrophic (BDNF) and proinflammatory markers (TNF-α, IL-6) in participants receiving tDCS. Multi-session protocols were more apt to drive clinically meaningful neuroplastic changes than single-session interventions. Conclusions: Although significant questions remain regarding optimal stimulation parameters, sample heterogeneity, and the translation of acute neural shifts into lasting behavioral benefits, this research confirms that tDCS can induce detectable neurobiological effects in SUD populations. By reshaping activity across prefrontal and reward-related circuits, modulating electrophysiological indices, and altering relevant biomarkers, tDCS holds promise as a viable, mechanism-based adjunctive therapy for SUDs. Rigorous, large-scale studies with longer follow-up durations and attention to individual differences will be essential to establish how best to harness these neuromodulatory effects for durable clinical outcomes. Full article

The study of neuronal electrical activity and spatial organization is essential for uncovering the mechanisms that regulate neuronal electrophysiology and function. Mathematical models have been utilized to analyze the structural properties of neuronal networks, predict connectivity patterns, and examine how morphological changes impact neural network function. In this study, we aimed to explore the role of the actin cytoskeleton in neuronal signaling via primary cilia and to elucidate the role of the actin network in conjunction with neuronal electrical activity in shaping spatial neuronal formation and organization, as demonstrated by relevant mathematical models. Our proposed model is based on the polygamma function, a mathematical application of ramification, and a geometrical definition of the actin cytoskeleton via complex numbers, ring polynomials, homogeneous polynomials, characteristic polynomials, gradients, the Dirac delta function, the vector Laplacian, the Goldman equation, and the Lie bracket of vector fields. We were able to reflect the effects of neuronal electrical activity, as modeled by the Van der Pol equation in combination with the actin cytoskeleton, on neuronal morphology in a 2D model. In the next step, we converted the 2D model into a 3D model of neuronal electrical activity, known as a core-shell model, in which our generated membrane potential is compatible with the neuronal membrane potential (in millivolts, mV). The generated neurons can grow and develop like an organoid brain based on the developed mathematical equations. Furthermore, we mathematically introduced the signal transduction of primary cilia in neurons. Additionally, we proposed a geometrical model of the neuronal branching pattern, which we described as ramification, that could serve as an alternative mathematical explanation for the branching pattern emanating from the neuronal soma. In conclusion, we highlighted the relationship between the actin cytoskeleton and the signaling processes of primary cilia. We also developed a 3D model that integrates the geometric organization unique to neurons, which contains soma and branches, such that the mathematical model represents the interaction between the actin cytoskeleton and neuronal electrical activity in generating action potentials. Next, we could generalize the model into a cluster of neurons, similar to an organoid brain model. This mathematical framework offers promising applications in artificial intelligence and advancements in neural networks. Full article

Background and Objectives: Deep brain stimulation (DBS) requires sedation strategies that enable rapid and reliable awakening during intraoperative electrophysiological testing. Although propofol and dexmedetomidine are commonly used, their lack of pharmacological antagonists might delay recovery. In this retrospective case series, we assessed the effects of using remimazolam, a short-acting benzodiazepine that is reversible with flumazenil. No existing research has determined whether this may represent a clinically advantageous alternative. Materials and Methods: Six patients who underwent DBS surgery with monitored anesthetic care between May and August 2024 were included. Two patients received dexmedetomidine and propofol combined, whereas four received remimazolam for initial sedation. The time from sedation discontinuation to intraoperative electrophysiological examination, postoperative hospital stays, and perioperative complications were evaluated. Results: Patients who received remimazolam had shorter awakening intervals (median 17 min) compared to those who received dexmedetomidine and propofol (median 50 min), with a large effect size difference (Cliff’s delta −1.00). In all cases of remimazolam, patients were administered flumazenil to facilitate awakening, and transient hypertension requiring nicardipine was observed in some patients. Among the patients who underwent unilateral DBS, those who received remimazolam had shorter postoperative hospital stays (5–7 days) than the patient who received dexmedetomidine and propofol (9 days). No patient had complications. Conclusions: This small retrospective case series indicated that remimazolam, when reversed with flumazenil, was associated with rapid awakening compared with dexmedetomidine and propofol in patients undergoing DBS surgery. However, these findings require validation in larger prospective studies due to the small sample size. Full article

Introduction: Propofol is a widely used sedative drug in electrophysiological studies (EPS). However, literature has shown that this drug may interfere with the cardiac conduction system (CCS). Our objective is to evaluate whether propofol interferes with CCS and the inducibility of arrhythmias during EPS. Method: A systematic review and a meta-analysis were performed. The databases were PubMed, Embase, Web of Science, and Scopus. Rayyan software was used to select the studies. Three Mesh terms were used: Propofol, Cardiac arrhythmias, Electrophysiologic Study, and Cardiac. Cohort studies and randomized clinical trials were included. Results: Only one of the six studies showed four cases where it was impossible to induce arrhythmia. We found no significant difference between propofol and the control group in the analyzed variables: cycle length, atrial-His, His-ventricular, corrected sinus node recovery time, atrial effective refractory factor, and ventricular effective refractory period, with low heterogeneity (I² = 0% to a maximum of I² = 8%). A significant difference in favor of the control group was found in the analysis of the atrioventricular node effective refractory period (MD:18.67 {95% CI 4.86 to 32.47} p = 0.008, I² = 44%). Discussion: The meta-analyzed data in this study showed that propofol possibly does not interfere with CCS, making it a safe drug for this type of procedure. Conclusions: However, extra care should be exercised with pediatric patients when the arrhythmia’s mechanism is automatic. More robust studies are still needed in this class. Full article

Accurately monitoring coupled water–nitrogen stress is critical for wheat (Triticum aestivum L.) productivity under climate change. This study developed a machine learning framework utilizing multimodal leaf electrophysiological signals––intrinsic resistance, impedance, capacitive reactance, inductive reactance, and capacitance––to decouple water and nitrogen stress signatures in wheat. A parallel modelling strategy was implemented employing Gradient Boosting, Random Forest, and Ridge Regression, selecting the optimal algorithm per feature based on predictive performance. Controlled pot experiments revealed IZ as the paramount biomarker across leaf positions, indicating its sensitivity to ion flux perturbations under abiotic stress. Crucially, algorithm-feature specificity was identified: Ridge Regression excelled in modeling linear responses due to its superior noise suppression, while GB effectively captured nonlinear dynamics. Flag leaves during reproductive stages provided significantly more stable predictions compared to vegetative third leaves, aligning with their physiological primacy as source organs. This framework offers a robust, non-invasive approach for real-time water and nitrogen stress diagnostics in precision agriculture. Full article

Background: Human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) allow for high-throughput evaluation of cardiomyocyte (CM) physiology in health and disease. While multimodality testing provides a large breadth of information related to electrophysiology, contractility, and intracellular signaling in small populations of iPSC-CMs, current technologies for analyzing these parameters are expensive and resource-intensive. Methods: We have designed a novel 2D/3D hybrid organoid system that can harness optical imaging techniques to assess electromechanical properties and calcium dynamics across CMs in a high-throughput manner. We validated our methods using a doxorubicin-based system, as the drug has well-characterized cardiotoxic, pro-arrhythmic effects. Results: This novel hybrid system provides the functional benefit of 3D organoids while minimizing optical interference from multilayered cellular systems through our cell-culture techniques that propagate organoids outwards into 2D iPSC-CM sheets. The organoids recapitulate contractile forces that are more robust in 3D structures and connectivity, while 2D CMs facilitate analysis at an individual cellular level, which recreated numerous doxorubicin-induced electrophysiologic and propagation abnormalities. Conclusions: Thus, we have developed a novel 2D/3D hybrid organoid model that employs an integrated optical analysis platform to provide a reliable high-throughput method for studying cardiotoxicity, providing valuable data on calcium, contractility, and signal propagation. Full article

Background/Objectives: Demyelination occurs to a variable extent in various neurological diseases, such as multiple sclerosis. Physical exercise benefits central neural functions that depend on the brain’s electrophysiological and glial activity. It is unclear whether both factors—i.e., demyelination and exercise—interact in the brain. We aimed to investigate if this interaction occurs during brain development. Methods: Developing rats were subjected to a cuprizone-induced demyelination. Part of these rats were treadmill-exercised for five weeks. After this period, some demyelinated animals were allowed to remyelinate by receiving a similar diet, without cuprizone, for six weeks. The exercised groups were compared with the corresponding sedentary groups. All groups were evaluated electrophysiologically (cortical spreading depression features), and their brains were processed for immunohistochemical labeling with four specific glial antibodies (anti-APC, MBP, GFAP, and Iba1). Results: Compared with the corresponding controls, cuprizone demyelination and treadmill exercise accelerated and decelerated CSD propagation. Cuprizone reduced APC, MBP, and GFAP immunolabeling and increased Iba1 immunostaining. Remyelination reverted the cuprizone effects. Exercise counteracted the cuprizone-induced changes in GFAP- and Iba1-containing cells but not in MBP- and APC-containing ones. Conclusions: Our data confirmed the effectiveness of the cuprizone demyelination paradigm. They evidenced the potential neuroprotective effect of regular physical exercise, suggesting that this non-pharmacological intervention could benefit patients with central demyelination-dependent diseases. Full article

Both biochemical cues and the electrophysiological microenvironment play a pivotal role in influencing cell behaviors. In this study, collagen/polypyrrole biomimetic electroactive composite coatings with a fiber network structure were constructed on the surface of titanium substrates by hot alkali treatment and stepwise electrochemical deposition. Materialistic characterization and electrochemical performance tests demonstrated that the titanium electrodes modified with collagen/polypyrrole composite coatings exhibited the surface morphology of a collagen film layer, and their electroactivity was significantly enhanced. Cellular experiments demonstrated that the collagen in the composite coatings could provide good biomimetic biochemical cues as a main extracellular matrix component, which have a substantial effect in promoting cell adhesion, proliferation, and osteogenic differentiation. Furthermore, under exogenous electrical signals, the polypyrrole coating has the capacity to facilitate an appropriate electrophysiological microenvironment, thereby promoting osteogenic differentiation. The collagen/polypyrrole composite coating exhibited a better effect in promoting osteogenic differentiation among all samples by simultaneously providing the appropriate biochemical cues and electrophysiological microenvironments. This work demonstrates the feasibility of synergistic pro-osteogenesis by biochemical cues and an electrophysiological microenvironment, which is instructive for the field of bone tissue engineering. Full article

Background: Traumatic brain injury (TBI) and hypoxic–ischemic encephalopathy (HIE) are major causes of long-term neurological disability in children, with limited options for effective neuronal recovery. Recent research has highlighted the therapeutic potential of nerve growth factor (NGF) in promoting neural repair through mechanisms such as neuroprotection, neurogenesis, and the modulation of neuroinflammation. This review evaluates the current evidence on NGF as a treatment strategy for pediatric brain injury, emphasizing its mechanisms of action and translational clinical applications. Methods: A comprehensive review was conducted using the PubMed, Scopus, and Cochrane CENTRAL databases to identify studies published between 1 January 1978 and 1 March 2025, investigating NGF in the context of brain injury. The inclusion criteria comprised studies assessing neurological outcomes through clinical scales, biochemical markers, neuroimaging, or electrophysiological examinations. Results: Seventeen studies met the inclusion criteria, encompassing both preclinical and clinical research. Preclinical models consistently demonstrated that NGF administration reduces neuroinflammation, enhances neurogenesis, and supports neuronal survival following TBI and HIE. Clinical studies, including case reports of pediatric patients treated with intranasal NGF, reported improvements in motor and cognitive function, neuroimaging findings, and electrophysiological parameters, with no significant adverse effects observed. Conclusions: NGF demonstrates significant promise as a neuroprotective and neuroregenerative agent in pediatric brain injury, with both experimental and early clinical evidence supporting its safety and efficacy. Large-scale controlled clinical trials are warranted to validate these preliminary findings and to determine the optimal dosage regimens and administration schedules for NGF in the treatment of TBI and HIE. Full article

TRPA1 (Transient Receptor Potential Ankyrin 1), a cation channel predominantly expressed in sensory neurons, plays a critical role in detecting noxious stimuli and mediating pain signal transmission. As a key player in nociceptive signaling pathways, TRPA1 has emerged as a promising therapeutic target for the development of novel analgesics. Crotalphine (CRP), a 14-amino acid peptide, has been demonstrated to specifically activate TRPA1 and elicit potent analgesic effects. Previous cryo-EM (cryo-electron microscopy) studies have elucidated the structural mechanisms of TRPA1 activation by small-molecule agonists, such as iodoacetamide (IA), through covalent modification of N-terminal cysteine residues. However, the molecular interactions between TRPA1 and peptide ligands, including crotalphine, remain unclear. Here, we present the cryo-EM structure of ligand-free human TRPA1 consistent with the literature, as well as TRPA1 complexed with crotalphine, with resolutions of 3.1 Å and 3.8 Å, respectively. Through a combination of single-particle cryo-EM studies, patch-clamp electrophysiology, and microscale thermophoresis (MST), we have identified the cysteine residue at position 621 (Cys621) within the TRPA1 ion channel as the primary binding site for crotalphine. Upon binding to the reactive pocket containing C621, crotalphine induces rotational and translational movements of the transmembrane domain. This allosteric modulation coordinately dilates both the upper and lower gates, facilitating ion permeation. Full article