Cholinergic degeneration contributes to hippocampal circuit dysfunction in Alzheimer's disease (AD). Ganglioside GM1 modulates membrane signaling and synaptic function, yet its acute effects on hippocampal neuronal activity under cholinergic-deficient conditions remain unclear. Using in vivo single-unit recordings in urethane-anesthetized male rats, extracellular single-unit activity was recorded from CA1 pyramidal neurons before and after systemic GM1 administration. We examined whether systemic GM1 alters spontaneous firing of CA1 pyramidal neurons in a nucleus basalis magnocellularis (NBM) lesion model of cholinergic hypofunction. GM1 (2, 5, 10 mg/kg, i.p.) produced dose-dependent increases in firing rate. Linear mixed-effects modeling, accounting for multiple neurons per animal, revealed a significant main effect of Time (F1,79 = 41.33, p < 0.001, partial η[2] = 0.34) and a significant Dose × Time interaction (F3,79 = 3.28, p = 0.025, partial η[2] = 0.11). Notably, NBM-lesioned animals exhibited amplified responses, particularly at 2 mg/kg (Δ = 7.22 ± 1.82 Hz), whereas control animals showed minimal change at this dose. GM1-induced increases remained within reported physiological firing ranges under urethane anesthesia. These findings demonstrate that GM1 enhances hippocampal CA1 excitability in a dose- and state-dependent manner, with heightened responsiveness in cholinergic-compromised networks. The results support the concept that membrane-targeting interventions may modulate dysfunctional circuits depending on baseline network state.

Organophosphate (OP) poisoning frequently results in respiratory failure and requires rapid atropine titration to clinical endpoints that are often subjective and difficult to assess in high-acuity emergency settings. We report the use of serial point-of-care lung ultrasound (LUS) as a complementary diagnostic adjunct during atropine escalation in severe OP poisoning. A young patient presented with severe cholinergic toxidrome and hypoxic respiratory distress. Baseline 4-zone anterior LUS demonstrated diffuse confluent B-lines consistent with marked interstitial-alveolar involvement. Atropine was administered using a sequential doubling strategy, and repeat LUS examinations during resuscitation demonstrated a progressive reduction in B-line burden corresponding with cumulative atropine dosing and clinical improvement. The patient recovered without requiring mechanical ventilation. This case illustrates a novel application of lung ultrasound as a complementary diagnostic adjunct during assessment of pulmonary involvement in acute OP poisoning and suggests a potential role for ultrasound in toxicologic resuscitation.

The dermal exposure to persistent nerve agents such as VX may lead to skin penetration and uptake in the circulatory system. So far, the efficacy of decontamination lotions to remove VX from the skin has been investigated in vitro using methods for transdermal drug delivery systems such as the vertical diffusion cell, which suffer from several disadvantages. We assessed a full thickness model of human skin placed in inserts of 6-well plates to investigate the efficacy of decontaminants to remove VX. Six different decontamination lotions (reactive skin decontamination lotion (RSDL), the potassium salt of the acetohydroxamic acid (AHAK), sodium hypochlorite (NaOCl) 2% and 10%, soapy water 2% and tap water) were evaluated by calculating the amount of VX that penetrated over 300 min. In addition, the impact of the initiation of decontamination (5 min versus 30 min) was investigated. Early decontamination of VX with AHAK was very effective resulting in a complete decontamination. RSDL and NaOCl 2% showed a substantial decontamination efficacy and the penetrated amount of VX was reduced by 88% (RSDL) and 84% (NaOCl 2%). In contrast, the decontamination efficacy of soapy water and tap water was significantly lower. The delayed decontamination was less effective but still the amount of penetrated VX was significantly reduced. In conclusion, the results underline that the full thickness model of human skin is a suitable tool for investigating the decontamination efficacy of various decontaminants. In addition, the model benefits from low technical requirements.

Metaldehyde is a highly selective molluscicide with moderate water solubility. Acute metaldehyde poisoning is most commonly reported in veterinary medicine and is extremely rare in humans. Its optimal clinical management remains poorly defined and warrants further investigation.

Despite it being banned under the Chemical Warfare Convention, VX is still being used, as demonstrated in 2017 with the assassination of Kim Jong Nam in Malaysia. In addition to conducting the typical forensic investigations, incidence of the deliberate use of chemical warfare agents (CWA) such as VX could also include undertaking chemical forensics to address questions including method of production, precursor-product-matching and batch-matching. The identification of residual impurities in VX, known as chemical attribution signatures (CAS), that allow for these questions to be addressed, would be beneficial to agencies undertaking these investigations. To increase the knowledge pool regarding CAS specific to a particular production method, five synthetic routes of VX formation were chemically profiled and subjected to multivariate analysis. In total, forty-one impurities of interest were identified that could be attributed to a production method. The structures of thirty-four were confirmed through a combination of database matching, accurate mass measurement, literature analysis and comparison with authentic standards. Several of these impurities were identified as candidate CAS for method attribution. Additionally, the longevity of the CAS was assessed by analysing samples after storage for 18 months at room temperature. While samples could not be classified (via MVA) to a specific production method, nineteen candidate CAS were still able to be identified. These results are suggestive that VX method of production may still be able to be elucidated on long term storage.

A multi-platform in silico framework was developed to characterize five selected A-series (Novichok) nerve agents-A-230, A-232, and A-234 (each evaluated using Ellison- and Mirzayanov-type structural representations) [1,2] together with A-242 and A-262-through integrated physicochemical, toxicological, and biological-activity prediction. Four complementary computational platforms (ACD/Labs Percepta, OECD QSAR Toolbox, EPA T.E.S.T., and PASS Online) were combined within a reproducible workflow to support Structure-Property-Toxicity Relationship (SPTR) interpretation across eight modeled structures (n = 8). Predicted partitioning behavior indicated moderate lipophilicity (logP (GALAS) ≈ 0.5-1.7) together with very low vapor pressure (0-0.05 mmHg at 25 °C), consistent with condensed-phase persistence and contact-driven exposure rather than sustained vapor dispersion. QSAR-derived LD50 values and dermal permeability coefficients varied across structural variants, demonstrating that predicted acute toxicity is not governed by a single descriptor. PASS-derived probabilities indicated elevated neurotoxicity likelihoods, while cholinergic activity probabilities showed stronger association with polarity-related descriptors (TPSA) than with lipophilicity alone. Principal Component Analysis (PC1 ≈ 81%, PC2 ≈ 13%) showed that descriptor variance was primarily driven by polarity-permeability balance rather than toxicity magnitude alone. Composite hazard ranking integrating inverse LD50, permeability, and neurotoxicity probability identified structural variants combining higher predicted permeability and elevated activity probabilities as comparatively higher within the modeled set. All findings are restricted to the studied compounds and represent computational predictions rather than experimental measurements, providing a transparent and regulatory-aligned framework for comparative, non-experimental hazard assessment under Chemical Weapons Convention constraints.

Nerve agents represent a significant hazard to human health and safety. Prompt reactivation of inhibited cholinesterase is imperative; however, the blood-brain barrier (BBB) impedes the delivery of cholinesterase reactivators to the central nervous system (CNS). This study aimed to develop brain-targeted reconstituted lipid nanoparticles (rLNPs) loaded with HI-6 (rLNPs/HI-6), with the goal of enhancing CNS delivery and improving reactivation efficacy in soman-poisoned mice. In healthy mice, rLNPs/HI-6 significantly enhanced BBB permeability to (11.47 ± 1.62)% and blood-cerebrospinal fluid barrier (BCSFB) permeability to (24.46 ± 2.65)%. In soman-poisoned mice (70% LD50), rLNPs/HI-6 further elevated BBB and BCSFB permeability to (22.95 ± 2.89)% and (41.12 ± 4.32)%. Importantly, rLNPs/HI-6 achieved a brain acetylcholinesterase (AChE) relative activity of (36.17 ± 1.95)%, which was 1.9-fold higher than that of free HI-6. These findings demonstrate that brain-derived rLNPs effectively enhance the CNS delivery efficiency of HI-6 and augment AChE reactivation efficacy by increasing BBB and BCSFB permeability, thereby offering a feasible strategy for central nervous system-targeted treatment of nerve agent poisoning.

The highly lethal organophosphorus nerve agent S-{2-[di(propan-2-yl)amino]ethyl} O-ethyl methylphosphonothioate (VX) irreversibly inhibits acetylcholinesterase (AChE), necessitating advanced bioscavengers. Herein, peptide P15 (WEIKPSSLTGKSPYFSNNHGKL) identified from a natural hydrolysate database via Python-assisted filtering and hierarchical virtual screening was prioritized by MMPBSA binding free energy (ΔGbind= -14.66 kcal/mol). Simulations reveal P15 neutralizes VX through a synergistic "scavenge-and-shield" mechanism. P15 directly sequesters free VX, while simultaneously inducing significant conformational and microenvironmental remodeling of the VX-AChE complex, selectively disrupting the electrostatic and hydrophobic networks requisite for VX accommodation. H-REMD/FEP calculations demonstrate this imposes a thermodynamic penalty (ΔΔG = +1.41 kcal/mol) on the VX-AChE complex. Steered molecular dynamics further showed P15 facilitates VX displacement, reducing the required rupture force by 53.3% (from 600 to 280 kJ/mol/nm). Supported by in vitro assays confirming P15's excellent biosafety (>100% cell viability), these computational findings indicate P15 integrates direct toxin scavenging with precise allosteric enzyme protection, serving as a promising dual-function countermeasure.

Organophosphorus compounds (OP), like pesticides and nerve agents, are potent inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) due to the phosphylation of their catalytic serine. Current treatment is limited, as approved oximes lack broad-spectrum efficacy and are poor reactivators of inhibited BChE. An alternative approach is pseudo-catalytic OP bioscavenging in which BChE and an efficient reactivator rapidly degrade OP in circulation, preventing it from reaching target tissues enriched with AChE. As imidazolium oximes were previously identified as potent BChE reactivators, we prepared eight novel N-substituted imidazolium oximes and tested them as reactivators of both human AChE and BChE inhibited by pesticide derivative paraoxon, and nerve warfare agents (sarin, cyclosarin, tabun VX, and five A-series agents). Oxime 3 (1,3-dibenzyl-2-hydroxy (imino)methylimidazolium bromide) was identified as the most potent reactivator, showing nanomolar affinity with native BChE and reactivation efficacy superior to standard oximes for cyclosarin-, sarin-, and tabun-BChE conjugate that was 1400-fold, 20-fold and 40-fold higher, respectively. In human whole blood, 30 μM cyclosarin was pseudo-catalytically decomposed by supplemented BChE and oxime 3, restoring 65% of total cholinesterase activity within 10 min. Although less potent, we identified two oximes capable of reactivating A-230-BChE conjugate. Furthermore, oxime 3 was not toxic to neural SH-SY5Y and hepatic HepG2 cells in concentrations relevant for biological activity. These findings highlight oxime 3 as well as the N,N'-dibenzyl imidazolium scaffold as the most potent BChE reactivators reported to date, providing a critical foundation for the advancement of bioscavenging-based therapies for OP poisoning.

Cadmium (Cd), a prevalent environmental toxin and pollutant capable of causing neurodegenerative diseases (NDs) like Alzheimer's and Parkinson's, primarily through oxidative stress, calcium imbalance, and neuroinflammation-induced mechanisms. Cd exposure increases the level of reactive oxygen species (ROS) and disrupts neurotransmitters by lowering antioxidants, leading to neuron death. Cd exposure in zebrafish results in neurodegeneration, with motor, mental, and behavioral impairments. The efficacy of the DOPA-31 intervention at varying concentrations was evaluated through the behavioral tests, biochemical assays for antioxidant enzyme activities (SOD, CAT, GSH, MDA), and histopathological analysis. Additionally, the alterations in expression levels of inflammation (tnf-α, il-1β) and neuroprotective (bdnf, syn2a) genes were also assessed. The Cd exposure exhibited the major deficits in the key behavioral parameters (motor, anxiety, and cognitive impairment). It disrupted antioxidant enzyme activity, increased lipid peroxidation, and elevated acetyl cholinesterase (AChE) activity, leading to cholinergic dysfunction. Histopathology showed extensive neuronal damage and amyloid-like protein aggregation. DOPA-31 at a 20 µM concentration, substantially exhibited antioxidant and AChE activity by reducing oxidative stress and improving motor and cognitive functions. Molecular analysis of DOPA-31 treatment showed significant downregulation of pro-inflammatory markers and upregulation of neuroprotective factors. In addition, DOPA-31 restored behavioral changes by potentially mitigating neuronal damage and protein aggregation caused by the Cd-induced neurotoxicity. This research investigation suggests the novel drug candidate DOPA-31 as a preliminary treatment for Neurodegenerative Disorder (NDD)-like features and warrants further exploration in higher animal models to assess clinical relevance.

Botulinum neurotoxin injections are used off-label to treat chronic pain, but their efficacy is limited and paralytic effects restrict clinical utility in these applications. Here, we investigated whether combining the light chain and translocation domains of botulinum neurotoxin A (BoNT/A) with the GM1-binding B subunit of cholera toxin would be beneficial in silencing pain-associated sensory neurons. Chimeric ChoBot was assembled via a coiled-coil linking technology and was shown to retain the enzymatic activity of BoNT/A in vitro and in vivo. In cultured dorsal root ganglion neurons, ChoBot cleaved SNAP25 in a calcitonin gene-related peptide (CGRP)-rich subpopulation of sensory neurons, resulting in marked inhibition of CGRP release. ChoBot had a lesser effect on the compound muscle action potentials of the rat gastrocnemius muscle than BoNT/A following subcutaneous injections. In rat models of pain, including chemotherapy-induced peripheral neuropathy, intraplantar administration of ChoBot significantly attenuated mechanical allodynia. Immunohistochemical analysis confirmed SNAP25 cleavage in NF200- and CGRP-expressing sensory fibres in the epidermis following a single injection. ChoBot also mediated SNAP25 cleavage in human neuroblastoma cells in culture. Together, these findings indicate that ChoBot enables a silencing of pain-associated sensory pathways, providing a new strategy for the development of new long-lasting analgesics for chronic pain.

Organophosphate (OP) exposure can trigger seizures within minutes and can rapidly evolve into status epilepticus (SE). Early seizure generation is plausibly driven by acetylcholinesterase inhibition, leading to central cholinergic overstimulation. With increasing seizure duration, experimental data are consistent with a time-dependent shift toward glutamatergic maintenance (NMDA/AMPA), oxidative stress, neuroinflammation, and progressive failure of GABAergic inhibition. This framework predicts a narrow window in which benzodiazepine (BDZ) monotherapy is most effective and a rising probability of BDZ non-response when seizures are prolonged, while anti-glutamatergic strategies may retain relative efficacy later in the course. This narrative review integrates clinical phenomenology, diagnostic limitations, and mechanistic evidence to propose an operational approach for OP-related seizures and SE in emergency settings. We discuss a pragmatic "Stage 1 Plus" framing for patients presenting after prolonged seizures or in non-convulsive SE with coma. Human evidence remains limited and heterogeneous, and inference is constrained by confounding due to delayed recognition, variable decontamination/resuscitation pathways, sparse EEG confirmation, and selection bias in mass-casualty reporting.

Botulinum neurotoxin serotype C (BoNT/C) exhibits therapeutic efficacy and duration of action comparable to those of BoNT/A. It has been demonstrated to effectively manage movement disorders such as dystonia and blepharospasm, making it a highly promising alternative to BoNT/A. BoNT/C is also one of the primary etiological botulinum isoforms causing animal botulism and may pose a zoonotic risk. So, it is of great need to develop antidote that can treat human iatrogenic, foodborne and animal botulism caused by BoNT/C. Currently, the approved botulism antidotes primarily are polyvalent horse serum antitoxins, which are severely limited due to insufficient supply and adverse reactions. In this study, we developed a high-affinity nanobody A2, a variable domain of a heavy-chain antibody (VHH) against BoNT/C, based on phage display library screening. Our results demonstrated that A2 effectively blocked the binding of BoNT/C to its target cell. Furthermore, A2 exhibited potent neutralizing activity and rescued BoNT/C-intoxicated mice. These findings supported nanobody A2 as a promising antitoxin candidate with therapeutic efficacy against botulism.