Non-ionotropic NMDAR signalling activates Panx1 to induce P2X4R-dependent long-term depression in the hippocampus.

In recent years, evidence supporting non-ionotropic signalling by the NMDA receptor (niNMDAR) has emerged, including roles in long-term depression (LTD). Here, we investigated whether niNMDAR-pannexin-1 (Panx1) contributes to LTD at the CA3-CA1 hippocampal synapse. Using whole-cell, patch clamp electrophysiology in rat hippocampal slices, we show that a low-frequency stimulation (3 Hz) of the Schaffer collaterals produces LTD that is blocked by continuous but not transient application of the NMDAR competitive antagonist, MK-801.

Catheter Ablation of Paroxysmal Atrial Fibrillation and Disease Progression: Magnitude of the anti-progression effect and role of intervention timing.

Background: Recent randomized controlled trials(RCT) have shown that catheter ablation of paroxysmal atrial fibrillation(AF) is associated with a lower incidence of progression to persistent AF compared to the use of antiarrhythmic drug(AAD) therapy.

Objective: This meta-analysis aimed to investigate the magnitude of the anti-progression effect of catheter ablation, as well as the effect of intervention timing.

Methods: MEDLINE/EMBASE databases were searched until April 1 2024 for RCTs comparing catheter ablation and AAD therapy for the treatment of paroxysmal AF and reporting the rate of progression to persistent AF at 3 years (PROSPERO CRD42024534288).

SSSort 2.0: A semi-automated spike detection and sorting system for single sensillum recordings.

Background: Single-sensillum recordings are a valuable tool for sensory research which, by their nature, access extra-cellular signals typically reflecting the combined activity of several co-housed sensory neurons. However, isolating the contribution of an individual neuron through spike-sorting has remained a major challenge due to firing rate-dependent changes in spike shape and the overlap of co-occurring spikes from several neurons. These challenges have so far made it close to impossible to investigate the responses to more complex, mixed odour stimuli.

Machine learning-assisted implantable plant electrophysiology microneedle sensor for plant stress monitoring.

Plant electrical signals serve as a medium for long-distance signal transmission and are intricately linked to plant stress responses. High-fidelity acquisition and analysis of plant electrophysiological signals contribute to early stress identification, thereby enhancing agricultural production efficiency. While traditional plant electrophysiology monitoring methods like gel electrodes can capture electrical signals on plant surfaces, which face limitations due to the plant cuticle barrier, impacting signal accuracy.

Heritable Burden of Community Sudden Death by Autopsy and Molecular Phenotyping for Precision Genotype Correlation.

Background: Sudden cardiac death (SCD) genetic studies neglect the majority occurring in older decedents with cardiovascular pathology.

Objectives: This study sought to determine the burden of genetic disease in unselected adult sudden deaths by precision genotype-postmortem phenotype correlation.

Methods: The authors used autopsy, histology, and toxicology to adjudicate cause and identify high-suspicion phenotypes (eg, hypertrophic cardiomyopathy) among presumed SCDs aged 18 to 90 years referred to the county medical examiner from February 2011 to January 2018.

Targeted Ganglionated Plexi Ablation With Nanoformulated Calcium Suppresses Postoperative AF Via Vagosympatholytic and Anti-Inflammatory Effects.

Background: The mechanisms underlying postoperative atrial fibrillation (POAF) remain unclear.

Objectives: The aim of this study was to test the hypothesis that targeted chemical ganglionated plexi (GP) modulation of all major left atrial-pulmonary vein GP using novel nanoformulated calcium chloride (nCaCl) can reverse postoperative neuroelectrical remodeling by suppressing vagosympathetic nerve activity and the localized inflammatory process, both critical substrates of POAF.

Methods: In a novel canine model of POAF with serial thoracopericardiotomies, sympathetic nerve activity (SNA), vagal nerve activity (VNA) and GP nerve activity (GPNA) were recorded; spontaneous and in vivo AF vulnerability were assessed; and atrial and circulating inflammatory markers and norepinephrine (NE) were measured to determine the neuroelectrical remodeling that promotes POAF and its subsequent modulation with nCaCl GP treatment (n = 6) vs saline sham controls (n = 6).

Understanding responses to multi-electrode epiretinal stimulation using a biophysical model.

Objective: Neural interfaces are designed to evoke specific patterns of electrical activity in populations of neurons by stimulating with many electrodes. However, currents passed simultaneously through multiple electrodes often combine nonlinearly to drive neural responses, making evoked responses difficult to predict and control. This response nonlinearity could arise from the interaction of many excitable sites in each cell, any of which can produce a spike.

Accelerated Infant Brain Rhythm Maturation in Autism.

Electroencephalography (EEG) captures characteristic oscillatory shifts in infant brain rhythms over the first year of life, offering unique insights into early functional brain development and potential markers for detecting neural differences associated with autism. This study used functional principal component analysis (FPCA) to derive dynamic markers of spectral maturation from task-free EEG recordings collected at 3, 6, 9, and 12 months from 87 infants, 51 of whom were at higher likelihood of developing autism due to an older sibling diagnosed with the condition. FPCA revealed three principal components explaining over 96% of the variance in infant power spectra, with power increases between 6 and 9 Hz (FPC1) representing the most significant age-related trend, accounting for more than 71% of the variance.

Concurrent processing of the prosodic hierarchy is supported by cortical entrainment and phase-amplitude coupling.

Models of phonology posit a hierarchy of prosodic units that is relatively independent from syntactic structure, requiring its own parsing. It remains unexplored how this prosodic hierarchy is represented in the brain. We investigated this foundational question by means of an electroencephalography (EEG) study.

Preprocedural Screening Tool to Guide Nonpulmonary Vein Trigger Testing in First-Time Atrial Fibrillation Ablation.

Background: Patients undergoing first-time atrial fibrillation (AF) ablation can benefit from targeting non-pulmonary vein (PV) triggers. Preprocedural identification of high-risk individuals can guide planning of ablation strategy. This study aimed to create a preprocedural screening tool to identify patients at risk of non-PV triggers during first-time AF ablation.

Identifying sex similarities and differences in structure and function of the sinoatrial node in the mouse heart.

Background: The sinoatrial node (SN) generates the heart rate (HR). Its spontaneous activity is regulated by a complex interplay between the modulation by the autonomic nervous system (ANS) and intrinsic factors including ion channels in SN cells. However, the systemic and intrinsic regulatory mechanisms are still poorly understood.

Retrospective Review Identifying Patients With Bacteremia and Intracardiac Devices With an Electronic Health Record Advisory.

Background: Cardiovascular implantable electronic device (CIED) infections without early diagnosis, treatment, and proper follow-up are associated with increased morbidity, mortality, and worse outcomes.  Objective: This study aims to identify patients presenting for hospital admission with bacteremia and the presence of CIED by implementing a best practice advisory (BPA) notification in the electronic medical record to facilitate early consultation with the cardiac electrophysiology (EP) team and treatment.

Methods: A BPA was implemented into the electronic medical record (EMR) EPIC in 2022 and was generated for any patient that presented to our health system with bacteremia and the presence of a CIED.

Atypical Wenckebach AV Block in the Infra-Hisian Region: Clinical Implications and Management.

BACKGROUND Second-degree atrioventricular (AV) block is a frequently encountered conduction abnormality on surface electrocardiogram (ECG). However, it does not always imply a block at the AV nodal level. In rare cases, this block can occur below the bundle of His, within the infra-Hisian region of the His-Purkinje system.

Transsynaptic labeling and transcriptional control of zebrafish neural circuits.

Deciphering the connectome, the ensemble of synaptic connections that underlie brain function, is a central goal of neuroscience research. Here we report the in vivo mapping of connections between presynaptic and postsynaptic partners in zebrafish, by adapting the trans-Tango genetic approach that was first developed for anterograde transsynaptic tracing in Drosophila. Neural connections were visualized between synaptic partners in larval retina, brain and spinal cord and followed over development.

A new stepwise approach to minimize phrenic nerve injury during cryoballoon pulmonary vein isolation.

Background: A phrenic nerve injury (PNI) during cryoballoon (CB) pulmonary vein isolation (PVI) continues to represent a limitation of this technique. The objective of this study was to develop a novel technique with the aim of reducing the incidence of PNI.

Methods: We performed a retrospective analysis of data from two hospitals in patients with symptomatic, drug-resistant atrial fibrillation (AF) over 7 years to evaluate the incidence and clinical characteristics of PNI during cryoballoon PVI.

Predicting Early recurrence of atrial fibrilation post-catheter ablation using machine learning techniques.

Background: Catheter ablation is a common treatment for atrial fibrillation (AF), but recurrence rates remain variable. Predicting the success of catheter ablation is crucial for patient selection and management. This research seeks to create a machine learning model to forecast the early recurrence of atrial fibrillation following catheter ablation.

Extracorporeal membrane oxygenation for patients with electrical storm or refractory ventricular arrhythmias: Management and outcomes.

Patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are at high risk for ventricular arrhythmias due to derangements in myocardial perfusion, hemodynamics, and heightened catecholamine states. Existing data on the management and outcomes of patients with electrical storm or refractory ventricular tachycardia/fibrillation (VT/VF) treated with VA-ECMO are primarily derived from retrospective observational studies. Typical survival rates are in the range of 40-50%, with 15-20% of patients undergoing VT ablation and 30-40% of patients requiring advanced heart failure therapies (cardiac transplant or durable left ventricular assist device).

Advancing Membrane Biology: Single-Molecule Approaches Meet Model Membrane Systems.

Model membrane systems have emerged as essential platforms for investigating membrane-associated processes in controlled environments, mimicking biological membranes without the complexity of cellular systems. However, integrating these model systems with single-molecule techniques remains challenging due to the fluidity of lipid membranes, including undulations and the lateral mobility of lipids and proteins. This mini-review explores the evolution of various model membranes ranging from black lipid membranes to nanodiscs and giant unilamellar vesicles as they adapt to accommodate electrophysiology, force spectroscopy, and fluorescence microscopy.

Dissecting the neuronal mechanisms of pinoresinol against methamphetamine addiction based on network and experimental pharmacology.

Background: Addiction is a chronic brain disease in which the underlying neuronal mechanism is characterized by drug-seeking and use. Flos Daturae (FD) and its components are used to treat addiction. However, the effective ingredients of FD that are linked to the neuronal mechanisms of seeking behavior remain unclear.

The mechanism of LQTS related CaM mutation E141G interfering with Ca1.2 channels function through its C-lobe.

Mutations in the CALM1-3 genes, which encode calmodulin (CaM), have been reported in clinical cases of long QT syndrome (LQTS). Specifically, the CaM mutant E141G (CaM) in the variant CALM1 gene has been identified as a causative factor in LQTS. This mutation disrupts the normal Ca-dependent inactivation (CDI) function of Ca1.

Quantification of Sympathetic Nerve Traffic to the Heart: Electrophysiological Recording of Cardiac Sympathetic Nerve Activity in a Rodent Model.

The accurate measurement of sympathetic nerve activity is essential for advancing knowledge related to the mechanisms that underpin sympathetic activation in diseased states, such as acute heart failure. Considering sympathetic outflow throughout the body is differentially modulated, the most reliable method of measuring sympathetic traffic to individual organs is by way of direct electrophysiological recording of nerve activity. However, the surgical approach of accessing, exposing, and isolating the sympathetic nerve of interest is technically demanding, especially in the small size of a standard laboratory rat, one of the most common models for measuring SNA.

Preparation of Human Atrial Trabeculae for Ex Vivo Analysis of Human Myocardial Function.

Human myocardial function can be investigated in the laboratory using human atrial trabeculae. These multicellular preparations provide a translatable model for assessing the ex vivo contractility, electrophysiology, and ionic and metabolic underpinnings of human cardiac muscle. Here, we detail the materials and methods required to determine the baseline function of a human atrial trabecula, from dissection to stimulation.

Isolation of Endothelial Cells from Human Internal Mammary Artery.

Endothelial cells are a major contributor to cardiovascular diseases. Studying their function and how they influence pathological processes remains an ongoing area of research. Although primary endothelial cells might be readily available from animals, translating results from these studies can be challenging due to species-dependent differences.

STING Driving Synaptic Phagocytosis of Hippocampal Microglia/Macrophages Contributes to Cognitive Impairment in Sepsis-Associated Encephalopathy in Mice.

Background: Sepsis-associated encephalopathy (SAE) is a serious neurologic complication in septic patients with poor prognoses. There is increasing evidence that stimulator of interferon genes (STING) plays a crucial role in neuroinflammation and cognitive impairment. However, whether sepsis associated with STING changes contributes to cognitive impairment is unknown.

Unweaving the Cognitive Map: A Personal History.

I have been incredibly fortunate to have worked in the field of hippocampal spatial coding during three of its most exciting decades, the 1990s, 2000s, and 2010s. During this time I had a ringside view of some of the foundational discoveries that were made which have transformed our understanding of the hippocampal system and its role in cognition (especially spatial cognition) and memory. These discoveries inspired me in my own lab over the years to pursue three broad lines of enquiry-3D spatial encoding, context and the sense of direction-which are outlined here.