Brain

Epileptic seizures exhibit marked phenotypic heterogeneity that reflects distinct underlying network mechanisms, yet these differences are incompletely captured by current clinical classifications. Computational models offer a principled approach to infer latent excitation-inhibition dynamics from intracranial EEG, enabling mechanism-informed seizure characterization. We analyzed 205 seizures from 15 patients with drug-resistant epilepsy from the European Epilepsy Database, covering seven clinically annotated seizure onset patterns. Using the Wendling neural mass model, we fitted five-second iEEG segments by optimizing synaptic excitation and inhibition parameters across four temporal windows spanning 60 s before to 25 s after seizure onset. Model-derived excitation-inhibition changes distinguished seizure types significantly above chance. Classification performance was strongest when combining excitation and inhibition parameters, with peridendritic inhibition being the single most discriminative parameter. Seizure-type-specific signatures were detectable not only during seizure onset and within seizure onset zones, but already during interictal periods and in non-onset channels, indicating that seizure mechanisms are preconfigured tens of seconds before clinical onset and extend beyond focal onset regions. Although all seizure types showed increases in both excitation and inhibition during seizure transition, their timing and magnitude differed systematically. In particular, our study supports and extends prior evidence that high-amplitude slow (HAS) seizures are driven by localized hyperexcitation within the seizure onset zone, whereas low-amplitude fast (LAF) seizures arise from inhibition-driven network mechanisms. Excitation-inhibition signatures were further linked to individual patient characteristics and surgical outcomes, highlighting their potential clinical relevance.

Hippocampal sclerosis is a frequent finding in pediatric epilepsy surgery and has traditionally been regarded as an acquired lesion. It commonly co-occurs with focal cortical dysplasia (FCD IIIa), yet whether hippocampal injury is secondary to seizures or reflects a shared underlying etiology remains unresolved. Here we identified somatic variants activating the RAS-MAPK pathway in 40% of patients with hippocampal sclerosis, but in none with non-sclerotic hippocampus. Gain-of-function variants in PTPN11 were the most common finding, with mutations present in both cortex and hippocampus and enriched in hippocampal neurons, consistent with a shared developmental origin. In mice, Ptpn11D61Y mutants developed profound hippocampal degeneration and gliosis following subthreshold kainic acid exposure, whereas wild-type controls were unaffected. p38-dependent stress pathways were upregulated in patients and mice, suggesting a mechanism through which ERK-p38 crosstalk lowers the threshold for seizure-induced injury. These results provide a genetic explanation for FCD IIIa, elucidate the role of somatic mutations within the RAS-MAPK pathway in driving hippocampal sclerosis, and provide a target for pathway-specific interventions for intractable seizures.

Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is an established thermoablative treatment for tremor. Although outcomes in Essential Tremor approach those of deep brain stimulation, efficacy in tremor-dominant Parkinsons disease (TDPD) is often less durable, with tremor relapse reported in 30-50% of cases. Previous associations with lesion size or age remain descriptive and do not explain why anatomically similar lesions yield divergent long-term outcomes. We retrospectively analyzed 20 patients with TDPD who underwent unilateral MRgFUS. Lesions were used as seeds for normative structural and functional connectivity analyses. Durable tremor control was associated with lesion showing stronger functional connectivity to primary motor (M1), primary somatosensory (S1), and supplementary motor areas, as well as inferior frontal and occipital cortices. In contrast, relapse was linked to greater connectivity with cerebellar motor and associative regions. Structurally, optimal lesions converged at the triangular interface of the nuclei ventralis intermedius, ventralis oralis, and ventro caudalis. Streamlines associated with better outcomes projected posteriorly towards S1, with M1 delineating an anterior functional boundary beyond which outcomes declined. Structural fingerprints emphasized posterior sensorimotor areas as critical therapeutic outputs. Findings define a connectivity-based substrate of durable tremor suppression and support the development of individualized, network-guided targeting strategies for MRgFUS in TDPD

Cognitive difficulties are increasingly recognized in juvenile myoclonic epilepsy (JME), but scalable biomarkers linking resting-state brain dynamics to general mental ability remain limited. Here, we combined topological data analysis, graph signal processing, machine learning, inverse Langevin modeling, and biophysical simulations to test whether EEG-derived network dynamics capture individual differences in general mental ability in JME. We studied 54 patients with JME and 45 healthy controls using resting-state high-density EEG and the raw estimated full-scale score derived from the Wechsler Abbreviated Scale of Intelligence (WASI), used here as an index of general mental ability. Subject-specific low-alpha activity was reconstructed with generalized eigendecomposition, and graph-derived features were extracted from the projection of topological and alpha-power signals onto the functional connectome, providing a graph-harmonic description of large-scale brain-state dynamics. In controls, dynamic EEG-derived features significantly predicted general mental ability, whereas the same framework failed in JME. Because prediction in controls was driven mainly by dynamic measures of smoothness (Dirichlet energy), we next examined the temporal organization of alpha-power smoothness using an inverse Langevin framework. Within the patient group, greater thermodynamic rigidity--that is, stronger confinement of fluctuations around preferred network states--was associated with lower general mental ability. Relative to controls, patients also showed lower thermodynamic noise, indicating a reduced tendency to explore alternative network regimes. Biophysical simulations suggested that reduced dendritic arborization can generate rigidity directly, whereas pharmacological stabilization of hyperexcitable circuits can shift the system toward a more rigid, lower-noise regime. Together, these findings suggest that cognition in JME is linked not only to altered resting-state network dynamics but also to stronger confinement of network-state fluctuations, with both intrinsic circuit abnormalities and treatment-related stabilization representing plausible routes to this rigid phenotype.

YWHAG Syndrome (Developmental and Epileptic Encephalopathy 56, DEE56) is an ultra- rare childhood epilepsy associated with neurodevelopmental delays, with no therapeutic intervention available. Multiple de novo mutations in the YWHAG gene, encoding for the 14-3-3{gamma} protein, have been identified as causative for YWHAG Syndrome. 14-3-3{gamma} interacts with various targets, including major neurodevelopmental signaling proteins such as components of the ROCK pathway. Despite substantial evidence of the essential role of 14-3-3{gamma} in neurite outgrowth, cytoskeletal rearrangements, and neuronal migration during cortical development, little is known regarding the molecular consequences of YWHAG mutations and their effect on neuronal function and survival. Here, we characterized an isogenic, pluripotent stem cell (iPSC) model of YWHAGR132C/+ cortical neurons. The YWHAGR132C/+iPSC-derived neurons exhibited early cytoskeletal phenotypes, coupled with an elevated calcium baseline, lower frequency of calcium spikes, and reduced network activity. The widespread alterations in the transcriptome of mutant neurons revealed a biphasic dysregulation in the core genes and modulators associated with the ROCK pathway that resulted in maturation-dependent changes to cytoskeletal protein stability and calcium phenotypes. Direct inhibition of ROCK with Y27632 further increased the calcium baseline compared to the isogenic control. Exposure of YWHAGR132C/+ neurons to Trypsin-EDTA revealed underlying cytoskeletal instability, which was partially reversed by lovastatin treatment. Further, lovastatin partially rescued the elevated calcium baseline, but not the frequency or amplitude of calcium spikes. Together, these results suggest decoupling of calcium homeostasis and calcium signaling associated with cytoskeletal instability in YWHAGR132C/+ neurons. These findings lay the groundwork for future mechanistic studies of YWHAG function and molecular therapeutic targets for YWHAG Syndrome and YWHAG-associated conditions.

Polyhydramnios, Megalencephaly, and Symptomatic Epilepsy syndrome (PMSE/STRADA-related disorder) is a rare neurodevelopmental disorder characterized by megalencephaly (ME), early-onset drug-resistant epilepsy, neurocognitive impairment, and high early mortality, often due to status epilepticus. PMSE is caused by a multi-exon deletion in STRADA, encoding STRADA, which regulates the mechanistic target of rapamycin (mTOR) pathway. GABAergic inhibitory interneurons (INs) critically modulate the excitatory:inhibitory balance in cortical and hippocampal networks, and IN deficits contribute to epileptogenesis in several epileptic encephalopathies. However, no studies have investigated INs in PMSE. We used a multimodal approach to study INs in a Strada-/- mouse model engineered with the same causative 5-exon deletion identified in human PMSE. We demonstrate that Strada/STRADA loss causes a reduction of INs in the somatosensory cortex and a corresponding increase in the striatum, representative of remnant ganglionic eminence progenitor origin, in Strada-/- mice and a single PMSE brain tissue specimen. RNA sequencing comparing wildtype to Strada-/- cortex and striatum corroborated these findings, revealing increased IN-related gene expression (e.g., Dlx2) in the striatum and decreased IN-related gene expression (e.g., Pvalb) in the developing cortex. Cytoskeletal (e.g., Tpp3, Kank4, Map1a) and mTOR-associated genes (e.g., Rictor, Cryab) are differentially expressed in the developing cortex, mature striatum, and mature cortex of Strada-/- mice. Functional validation confirmed enlarged INs in mouse and human Strada/STRADA-deficient brain and enhanced S6 phosphorylation in Strada-/- striatum. Together, these findings suggest STRADA/Strada loss contributes to failed IN migration -- the first such report in a developmental, mTOR-associated megalencephaly syndrome -- highlighting INs as a therapeutic target for seizure prevention in PMSE. Key PointsO_LI- Reduced numbers of cortical inhibitory interneurons were observed in the cerebral cortex of Strada-/- mice, with striatal interneuron aggregation C_LIO_LI- Reduced numbers of cortical inhibitory interneurons, with an aggregation in striatum, were observed in human PMSE brain, supporting the observations in Strada-/- mouse C_LIO_LI- Transcriptomic analysis in Strada-/- mice reveals evidence of early developmental interneuron and cytoskeletal dysfunction C_LIO_LI- We introduce a loss of cortical interneurons as a salient feature of PMSE developmental pathogenesis, potentially contributing to a loss of inhibitory modulation C_LIO_LI- This is the first study proposing interneuron migration impairment in the developmental pathogenesis of an mTOR-associated megalencephaly syndrome C_LI

BackgroundGangliogliomas (GGs) are low-grade glioneuronal tumors that frequently present with drug-resistant epilepsy. Although their indolent course contrasts with their high epileptogenic potential, the oncogenic mechanisms sustaining neuronal precursor-like populations within the tumor microenvironment remain poorly defined. MethodsWe performed spatial transcriptomic profiling on eight histologically confirmed GGs and matched healthy cortex to map the cellular and molecular architecture of the tumor microenvironment. Integrated analysis with weighted gene correlation network analysis (WGCNA) defined recurrent oncogenic programs and spatially resolved tumor-stroma interactions. ResultsEight conserved gene modules emerged, encompassing physiological cortical, reactive glial, and oncopathological programs. The latter captured extracellular matrix (ECM) remodeling, vascular-immune signaling, and persistence of immature, proliferative neuronal-like states. Spatial modeling revealed that these oncopathological programs form structured niches at the tumor-brain interface, where radial glia-derived neuronal-like tumor cells coexist with immune and stromal elements engaged in ECM turnover and cytokine signaling. ConclusionsGanglioglioma represents a hybrid glioneuronal neoplasm in which developmental neuronal programs are co-opted by tumor-associated stromal and immune cues. This convergence establishes a permissive oncogenic niche that sustains precursor-like tumor cells and provides a mechanistic basis for both the tumors benign growth and its intrinsic epileptogenicity. Key PointsO_LISpatial transcriptomics identifies reproducible transcriptional programs that define the ganglioglioma microenvironment. C_LIO_LITumor-associated regions show transcriptional programs consistent with immature neuronal states together with ECM remodelling and immune activity. C_LIO_LISingle-cell reference data indicate that immature neuronal programs in ganglioglioma resemble radial glia-derived developmental states. C_LI Importance of the StudyGanglioglioma is a low-grade glioneuronal tumor that combines benign growth with pronounced epileptogenicity, yet the molecular basis of this dual behavior remains poorly understood. Through spatial transcriptomics integrated with single-cell analysis, we reveal that ganglioglioma architecture is defined by two interacting transcriptional axes: a residual glioneuronal network and a tumoral niche enriched for extracellular-matrix, vascular, and immune programs. Within these niches, immature neuronal-like tumor cells persist in a developmentally arrested state maintained by ECM-immune signaling. This spatially organized interplay between physiological and pathological programs explains both the low oncologic aggressiveness and high excitability of these lesions. Our findings provide molecular signatures that may refine diagnostic classification within the LEAT spectrum, delineate epileptogenic zones, and identify candidate pathways for therapeutic modulation of the ganglioglioma microenvironment.

Normal pressure hydrocephalus (NPH) is a potentially reversible neurological disorder characterized by urinary incontinence, gait impairment, and cognitive decline. However, postoperative improvement after shunt placement is variable, and reliable preoperative predictors are lacking, leaving patients exposed to uncertain surgical benefit and procedural risk. We therefore asked whether preoperative cerebrospinal fluid (CSF) metabolic profiles capture biological states associated with recovery potential. We analyzed ventricular CSF from patients undergoing shunt placement and identified metabolic patterns that differed between patients who improved postoperatively and those who did not. These signatures were detectable prior to intervention and were consistent across analytical approaches and patient cohorts. Multivariate models based on metabolite features were associated with postoperative improvement, with strongest performance observed for cognitive outcomes. Pathway-level analyses indicated coordinated alterations in processes related to redox balance, immune-metabolic signaling, and energy substrate utilization. These findings indicate that preoperative CSF metabolite profiles reflect biological states associated with recovery potential in NPH. The results further suggest that metabolic and immune-metabolic processes contribute to variability in surgical responsiveness and support the development of predictive biomarkers for patient stratification.

To date, FBRSL1-related disorder has been reported in five individuals with congenital abnormalities and severe postnatal impairment with or without epilepsy; however, the full extent of the phenotypic and genotypic spectrum remains unclear. Previously reported cases involved small truncating variants apparently escaping nonsense-mediated decay, suggesting either a haploinsufficiency or a dominant-negative mechanism. We report the first case of a complex structural variant at the FBRSL1 locus, resulting in an additional, partially truncated copy of the gene, providing strong evidence for a dominant-negative mechanism. RNA-Seq supported the expression of the additional truncated gene copy. The patient is an infant girl with a profound developmental and epileptic encephalopathy (DEE). The child presented at birth with intrauterine growth restriction, respiratory insufficiency, severe swallowing dysfunction, spasticity, contractures, optic nerve hypoplasia, facial dysmorphism, and atrial septal defect. She developed severe postnatal growth restriction with microcephaly and profound developmental impairment. She has a DEE with frequent neonatal focal seizures evolving to infantile epileptic spasms syndrome (IESS). Our patient has congenital abnormalities in common with previously reported cases, along with a profound DEE, not associated previously with FBRSL1. Our case expands both the phenotypic and genotypic spectrum of FBRSL1-related disorder.

Parkinsons disease (PD) exhibits substantial genetic heterogeneity, yet how combinations of rare variants converge on disease-relevant cellular mechanisms remains unclear. Here, we generated human induced pluripotent stem cell-derived dopaminergic neurons from PD patients carrying rare variants in recently implicated genes and performed integrated electrophysiological, proteomic, lipidomic, and genetic analyses. Patient-derived neurons showed reduced membrane capacitance and altered action potential firing, indicating impaired intrinsic excitability and synaptic dysfunction, with marked variability across genetic backgrounds. Multi-omics profiling revealed dysregulation of mitochondrial function, glycolysis, and oxidative phosphorylation, accompanied by extensive lipid remodeling, including increased fatty acids, acylcarnitines, and sphingolipids, and reduced gangliosides. These alterations were more pronounced in neurons harboring specific variant combinations in KIF21B, SLC6A3, HMOX2, TMEM175, and AIMP2. Integrative analyses uncovered coordinated protein-lipid changes linking mitochondrial dysfunction and membrane homeostasis. Notably, Calpastatin and CXCR4 were consistently dysregulated across PD neurons. Genetic association analyses in independent cohorts identified PD-associated variants in genes encoding dysregulated proteins, supporting the functional relevance of these pathways. Overall, our results define convergent and variant-specific mechanisms underlying PD and highlight candidate biomarkers and therapeutic targets.

De novo SYT1 mutations cause Baker-Gordon syndrome (BAGOS), yet the pathogenic mechanisms are not well understood, and no disease-modifying therapies exist. We identified a child carrying a newly described SYT1 variant, D310N, and compared this case to a previously reported D366E variant. Across all phenotypic domains evaluated, the D310N variant produced a consistently more severe clinical phenotype. To investigate the biological basis of these differences, we generated Drosophila models harboring each variant. Heterozygous D310N flies displayed substantially greater locomotor impairment, higher incidences of seizure-like activity, and more pronounced deficits in learning and memory than flies expressing D366E. At synapses, both variants disrupt synaptic vesicle (SV) recycling during repetitive stimulation. These fly models enable us to gain further insight into BAGOS otherwise not possible with cell culture. Namely, we have identified a mid-larval developmental window during which variant expression induces life-long locomotor abnormalities even though the mutant SYT1 protein is no longer detectable in adult flies. Yet, mutant SYT1 expressed in adult stage does not have a detectable effect on climbing for over 10 days, arguing that BAGOS is likely caused by developmentally disrupted networks rather than synaptic transmission alone. Finally, we show that cholinergic interneurons are major common drivers of the observed locomotor deficits whereas expression of mutant SYT1 in cholinergic and GABAergic neurons induces seizure-like activity. Together, these findings recapitulate core clinical manifestations and uncover variant-specific disruptions in SV recycling, developmental timing, and circuit-level contributions. This integrated human-fly analysis advances understanding of SYT1-associated neurodevelopmental disorders and highlights discrete developmental periods and neuronal subtypes as potential therapeutic targets.

Myelin oligodendrocyte basic protein (MOBP) is an abundant oligodendrocyte gene implicated in multiple neurodegenerative diseases. Genetic variation at the MOBP locus has been associated with risk for progressive supranuclear palsy (PSP), amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTD), corticobasal degeneration (CBD), Alzheimers disease (AD), Lewy body dementia (LBD), and Creutzfeldt-Jakob disease (CJD). Epigenetically, MOBP promoter hypermethylation and reduced expression have been reported in multiple system atrophy (MSA). Although MOBP is thought to play a role in oligodendrocyte morphology and myelin structure, how genetic and epigenetic variation at this locus influences gene regulation and contributes to disease risk remains poorly understood across neurodegenerative disorders. Here, we investigated whether shared or disease-specific genetic mechanisms at MOBP converge on altered DNA methylation and expression across neurodegenerative disorders. We analysed MOBP variants using summary statistics from recent GWAS for ALS, PSP, FTD, LBD, PD, MSA, AD, and CJD. Colocalisation (COLOC and SuSiE-coloc) was used to test whether disease-associated variants overlapped between diseases, and with oligodendrocyte expression quantitative trait loci (eQTLs) and bulk brain methylation quantitative trait loci (mQTLs). To further investigate mQTL effects at this locus, rs1768208, a variant previously associated with PSP, was genotyped in an overlapping brain methylation cohort, allowing direct testing of genotype-methylation associations in frontal white matter tissue. ALS and PSP GWAS demonstrated strong association at MOBP, with most strongly associated SNPs (e.g. rs631312, rs616147, rs1768208) shared between both disorders. Colocalisation analyses indicated high posterior probability that ALS and PSP share the same causal variant, with weaker overlap with FTD. mQTL colocalisation highlighted cg15069948, located near an exon junction within MOBP, as strongly colocalising with the ALS/PSP risk variants. In complementary tissue analyses, rs1768208-T carriers showed hypomethylation at cg15069948 in PSP brains. No genotype-methylation effects were detected in MSA or Parkinsons disease. Together with prior evidence of promoter hypermethylation and reduced expression in MSA, our findings identify cg15069948 as a regulatory methylation site linking ALS/PSP risk variants to altered MOBP methylation, and support MOBP dysregulation as a shared feature of neurodegeneration. However, the underlying mechanisms appear disease-specific, highlighting the complexity of involvement of this gene across neurodegenerative disorders.

Psychosis is increasingly understood as a disorder of disrupted cortical excitation-inhibition balance, yet robust non-invasive translational biomarkers remain lacking. The resting-state fMRI Hurst exponent (HE) and EEG aperiodic spectral exponent are promising complementary biomarkers, with lower values in each proposed to reflect a shift towards cortical hyperexcitability, but they have not been jointly examined in psychosis, and the spatial and molecular architecture of HE alterations remains poorly defined. We therefore tested for convergent systems-level signatures across independent cohorts and modalities, using resting-state fMRI (107 patients, 53 controls) and EEG (547 patients, 363 controls). Whole-brain and regional HE were estimated using wavelet methods, and EEG aperiodic exponents were quantified using spectral parameterisation. Compared with healthy controls, individuals with psychosis showed reduced whole-brain HE and widespread regional reductions. Regional HE case-control differences were associated with cortical gene-expression patterns, with enrichment for potassium channel and GABA receptor pathways, and correlated with noradrenergic, muscarinic, serotonergic, glutamatergic and dopaminergic receptor density maps, but not with cortical thickness or symptom or cognitive measures. In the independent EEG cohort, psychosis was similarly associated with a reduced aperiodic spectral exponent. Together, these findings provide cross-modal evidence for altered cortical resting-state dynamics in psychosis, consistent with a shift towards cortical hyperexcitability. Integration with receptor-density and transcriptomic maps implicates biologically plausible molecular pathways and supports HE and EEG aperiodic activity as scalable translational biomarkers in psychosis.

Despite its prevalence and clinical impacts, epilepsy remains incompletely understood in terms of the population dynamics that mediate seizure susceptibility, initiation, and propagation across brain-wide networks. In this study, we have performed calcium imaging in zebrafish, brain-wide and at cellular resolution, at baseline and as seizures are induced using the GABAA receptor antagonist pentylenetetrazol (PTZ). We have then modeled the network architecture in wild-type and scn1lab-/- larvae, which are seizure-prone and serve as a model for Dravet syndrome. scn1lab-/- larvae show increased pair-wise correlations between neurons when exposed to PTZ, and graph analyses of these correlations revealed genotype-specific network alterations during seizures, identifying regions and metrics linked to seizure onset. Using generative network modeling, we then explored the wiring rules that govern activity in these networks, identifying specific network properties linked to seizure susceptibility that were only detectable using large-scale, cellular-resolution data. Even at baseline in the absence of seizures, these rules differed by genotype in a way that enabled the identification of scn1lab-/- larvae and predicted individuals seizure risk independently of their observable phenotype. These findings uncover the cellular-resolution network properties of a zebrafish model of Dravet syndrome and establish a predictive framework for seizure susceptibility grounded in multi-scale functional connectivity.

Parkin, an E3 ubiquitin ligase encoded by PARK2, plays a key role in both hereditary and sporadic Parkinsons disease (PD), yet there are no therapies currently available that can target this important pathway. Here, we show that Parkin is critical for successful neuronal differentiation and survival, and we develop small-molecule Parkin agonists that can protect dopaminergic neurons. Upon differentiation of neural progenitor cells, loss of Parkin results in a reduced capacity to maintain neuronal cell state, dopaminergic neuronal phenotypes, and stress resistance. Moreover, Parkin loss disrupted cell morphology and the stability of neurites. Transcriptional and single-cell analyses reveal that Parkin controls critical pathways regulating stem-like cell transitions and is needed for stable neuronal maturation. We also examined the effects of FB231, a small molecule enhancer of Parkin E3 ligase activity, in models of PD. FB231 reduced pathological -synuclein and enhanced cell survival in human iPSC-derived dopaminergic neurons treated with -synuclein preformed fibrils. Furthermore, FB231 attenuated -synuclein pathology and dopaminergic neurodegeneration in a gut -synuclein murine model of PD. Our findings support that Parkin plays a crucial role in maintaining neuronal homeostasis and that pharmacologic activation of Parkin may be a promising strategy to attenuate neurodegeneration in PD.

Patients with functional neurological disorders (FNDs) show impaired control of voluntary actions in the absence of organic neurological damage. The inconsistency between objective neurological clinical signs and actual performance of the same movements in slightly different contexts points to an abnormal self-focused attentional role towards movement execution. Yet, it remains unexplained what triggers a higher level of self-focused attention in FNDs and how this interferes with voluntary movements. Given the known threat sensitivity manifested by patients with FNDs, I hypothesized that under negative affective conditions self-focused attention might be heightened in FNDs in an automatic way so as to impede the execution of a voluntary action. Specifically, I used fMRI to investigate effective brain connectivity in "self-referential" and "limbic" circuits to delineate the causal functional architecture accounting for the FND specific activity when preparing a movement under aversive conditions with different levels of emotion awareness. Seventeen FND participants and seventeen healthy volunteers performed a motor task (key press and release) after having been exposed to an aversive or neutral picture prime using a sandwich mask paradigm. Behaviorally, the FND group had showed a slower reaction time across all task conditions and a high rate of missing key-press responses following associated to aversive primes. Dynamic Causal Modeling (DCM) analyses showed that the FND group emotional information did not engage a limbic network as observed in the healthy control group, but rather a different self-referential associated network. In this functional architecture, the aversive masked condition exerted a direct inhibitory effect on forward connections between the left IFG and left precentral motor cortex. These findings show how affective processing can impact on voluntary motor control in FND, helping to reduce the explanatory gap between emotionality and readiness to act as a potential process of functional motor symptom production.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease with a heterogeneous clinical presentation, complicating early diagnosis and therapeutic monitoring. To identify disease-specific biomarkers, we performed an unbiased cerebrospinal fluid (CSF) proteomic analysis in 87 ALS patients, 89 healthy controls, and 61 neurological controls using mass spectrometry. Across all quantified proteins, 399 were significantly dysregulated in ALS, including established neurodegeneration (NEFL, NEFM, UCHL1) and neuroinflammatory (CHIT1, CHI3L1, CHI3L2) markers. Correlation and pathway analyses uncovered dysregulation of immune, synaptic, and metabolic processes, with aberrant complement activation emerging as a hallmark. Complement proteins increased progressively with declining ALS Functional Rating Scale-Revised and longer disease duration, whereas early-stage markers (CLSTN3, CHAD, RELN) indicated pre symptomatic neuronal and synaptic disruptions. Machine learning identified a minimal five protein CSF panel (MB, ITLN1, YWHAG, FCGR3A, PGAM1) that accurately distinguished ALS patients from healthy controls, capturing disease-specific pathophysiology beyond general neurodegeneration. Our findings define a robust ALS-specific CSF proteomic signature, reveal prognostic protein candidates across disease stages, and provide a framework for diagnostic biomarker development, enabling earlier intervention and monitoring.

In the Global Parkinson's Genetics Program (GP2) we aim to advance precision medicine by integrating large-scale clinico-genetic data from diverse populations worldwide. We investigated potentially trial-eligible carriers of pathogenic and high-risk GBA1 and LRRK2 variants and conducted a global precision-medicine survey across GP2 sites. Among 65,509 individuals with Parkinson's disease, we identified 9,019 (13.8%) potentially trial-eligible genetic variant carriers, including 6,789 GBA1, 2,084 LRRK2, and 146 dual GBA1-LRRK2 carriers. Individuals were distributed across multiple global regions, many of which currently lack active gene-targeted trials, highlighting a global disparity between relevant variant carriers and the availability of disease modifying treatment trials. GP2's unified framework supports equitable recruitment for gene-targeted therapeutic studies and helps address critical gaps in Parkinson's disease genetics and future therapeutic development.

BackgroundFilamentation induced by cAMP domain-containing protein (FICD) is an endoplasmic reticulum (ER)-resident adenylyltransferase that catalyzes protein AMPylation, a post-translational modification. Although FICD-mediated AMPylation has been linked to the fine-tuning of proteostasis and neuronal integrity, its role in neurodegenerative diseases characterized by protein dyshomeostasis remains unclear. Parkinsons disease (PD) is defined by dopaminergic neurodegeneration and aggregation of -synuclein (aSyn) as a consequence of impaired protein homeostasis. We therefore investigated whether dysregulated FICD-mediated AMPylation contributes to PD pathogenesis. MethodsWe combined analyses of human post-mortem PD brain tissue with complementary models, including midbrain dopaminergic neurons derived from human induced pluripotent stem cells (hiPSCs) of a PD patient carrying an SNCA gene duplication and its isogenic gene dosage-corrected control line, transgenic mouse models of synucleinopathy, and an aSyn-overexpressing H4 neuroglioma cell model. Genetic and pharmacological modulation of FICD activity was integrated with multi-proteomic approaches, including chemical proteomics-based AMPylation profiling, stable isotope labelling with amino acids in cell culture-based global protein turnover analysis, and whole-proteome profiling to identify AMPylation-associated molecular pathways. ResultsFICD was preferentially expressed in dopaminergic neurons and was upregulated in SNCA duplication PD patient-derived neurons, as well as in the basal ganglia of PD post-mortem brains and synucleinopathy mice. Despite this overall increase, the proportion of FICD-expressing dopaminergic neurons was reduced under PD conditions, suggesting selective vulnerability of dopaminergic neurons to FICD. Mechanistically, FICD selectively AMPylated lysosomal proteins, thereby linking AMPylation to the regulation of degradative pathways. Moreover, hyperactivation of FICD-induced AMPylation triggered ER stress, impaired lysosomal function, reduced protein turnover, and ultimately promoted aSyn aggregation and apoptotic cell death. Importantly, pharmacological inhibition of AMPylation reversed aSyn pathology and neurite degeneration in PD patient-derived neurons. ConclusionsWe identify the pathological relevance of FICD-mediated AMPylation in PD-related neurodegeneration and its contribution to aSyn aggregation through a bidirectional interplay with aSyn pathology. Our findings support FICD-mediated AMPylation as a defining molecular switch regulating intracellular protein homeostasis in PD and highlight the FICD-AMPylation pathway as a potential therapeutic target for restoring aSyn pathology and mitigating disease progression.

Biallelic variants in genes regulating endosomal, lysosomal and autophagy pathways are increasingly implicated in severe neurodevelopmental disorders, yet the contribution of the Rab7 effector WDR91 to human disease remains incompletely defined. We report a child with a severe neurodevelopmental disorder characterized by progressive microcephaly, microlissencephaly, corpus callosum hypoplasia, and early-onset epilepsy, harboring compound heterozygous WDR91 variants: a truncating variant (p.Gln215*) and a missense variant (p.Tyr15Asn). Functional analyses show that p.Gln215* abolishes WDR91 expression, whereas p.Tyr15Asn reduces protein abundance through increased degradation. Reduced WDR91 expression was confirmed in primary patient-derived cells. In silico analyses suggest that p.Tyr15Asn induces a localized change within an N-terminal degron-containing region, potentially affecting protein stability. In cellular models, both variants impair early-to-late endosomal maturation and alter WDR91 localization to Rab7-positive compartments. WDR91 deficiency is further associated with transcriptional and functional evidence of autophagy dysregulation. While the p.Tyr15Asn variant partially restores autophagic flux under overexpression conditions, patient-derived cells display impaired autophagic turnover, consistent with a context-dependent functional and partial loss of function effect of this variant. Together, these findings provide functional evidence supporting the pathogenicity of WDR91 variants and implicate combined defects in endosomal maturation and autophagy in WDR91-related neurodevelopmental disease.