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The mammalian auditory system encodes sounds with subtypes of spiral ganglion neurons (SGNs) that differ in sound level sensitivity, permitting discrimination across a wide range of levels. Recent work suggests the physiologically defined SGN subtypes correspond to at least three molecular subtypes. It is not known how information from the different subtypes converges within the cochlear nucleus. We examined this issue using transgenic mice of both sexes that express Cre recombinase in SGNs that are positive for markers of two subtypes: CALB2 (calretinin) in type 1a SGNs and LYPD1 in type 1c SGNs, which correspond to high- and low-sensitivity subtypes, respectively. We crossed these with mice expressing floxed channelrhodopsin, which allowed specific activation of axons from type 1a or 1c SGNs using optogenetics. We made voltage-clamp recordings from bushy cells in the anteroventral cochlear nucleus (AVCN) and found that the synapses formed by CALB2- and LYPD1-positive SGNs had similar EPSC amplitudes and short-term plasticity. Immunohistochemistry revealed that individual bushy cells receive a mix of 1a, 1b, and 1c synapses with VGluT1-positive puncta of similar sizes. We used optogenetic stimulation during in vivo recordings to classify chopper and primary-like units as receiving versus nonreceiving 1a- or 1c-type inputs. These groups showed no significant difference in threshold or spontaneous rate, suggesting the subtypes do not segregate into distinct processing streams in the AVCN. Our results indicate that principal cells in the AVCN integrate information from all SGN subtypes with extensive convergence, which could optimize sound encoding across a large dynamic range., Competing Interests: The authors declare no competing financial interest., (Copyright © 2024 the authors.)

Metaxins are a family of evolutionarily conserved proteins that reside on the mitochondria outer membrane (MOM) and participate in the protein import into the mitochondria. Metaxin-2 (Mtx2), a member of this family, has been identified as a key component in the machinery for mitochondrial transport in both C. elegans and human neurons. To deepen our understanding of Mtx2's role in neurons, we examined the homologous genes CG5662 and CG8004 in Drosophila. The CG5662 is a non-essential gene while CG8004 null mutants die at late pupal stages. The CG8004 protein is widely expressed throughout the Drosophila nervous system and is targeted to mitochondria. However, neuronal CG8004 is dispensable for animal survival and is partially required for mitochondrial distribution in certain neuropil regions. Conditional knockout of CG8004 in adult gustatory receptor neurons (GRNs) impairs mitochondrial trafficking along GRN axons and diminishes the mitochondrial quantities in axon terminals. The absence of CG8004 also leads to mitochondrial fragmentation within GRN axons, a phenomenon that may be linked to mitochondrial transport through its genetic interaction with the fusion proteins Marf and Opa1. While the removal of neuronal CG8004 is not lethal during the developmental stage, it does have consequences for the lifespan and healthspan of adult Drosophila. At last, double knockout (KO) of CG5662 and CG8004 shows similar phenotypes as the CG8004 single KO, suggesting that CG5662 does not compensate for the loss of CG8004. In summary, our findings suggest that CG8004 plays a conserved and context-dependent role in axonal mitochondrial transport, as well it is important for sustaining neuronal function. Therefore, we refer to CG8004 as the Drosophila Metaxin-2 (dMtx2)., Competing Interests: Conflicts of interest: The authors declare no competing interests., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Genetics Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Excitatory synapses and the actin-rich dendritic spines on which they reside are indispensable for information processing and storage in the brain. In the adult hippocampus, excitatory synapses must balance plasticity and stability to support learning and memory. However, the mechanisms governing this balance remain poorly understood. Tiam1 is an actin cytoskeleton regulator prominently expressed in the dentate gyrus (DG) throughout life. Previously, we showed that Tiam1 promotes dentate granule cell synapse and spine stabilization during development, but its role in the adult hippocampus remains unclear. Here, we deleted Tiam1 from adult forebrain excitatory neurons ( Tiam1 fKO ) and assessed the effects on hippocampal-dependent behaviors. Adult male and female Tiam1 fKO mice displayed enhanced contextual fear memory, fear extinction, and spatial discrimination. Investigation into underlying mechanisms revealed that dentate granule cells from Tiam1 fKO brain slices exhibited augmented synaptic plasticity and N-methyl-D-aspartate-type glutamate receptor (NMDAR) function. Additionally, Tiam1 loss in primary hippocampal neurons blocked agonist-induced NMDAR internalization, reduced filamentous actin levels, and promoted activity-dependent spine remodeling. Notably, strong NMDAR activation in wild-type hippocampal neurons triggered Tiam1 loss from spines. Our results suggest that Tiam1 normally constrains hippocampal-dependent learning and memory in the adult brain by restricting NMDAR-mediated synaptic plasticity in the DG. We propose that Tiam1 achieves this by limiting NMDAR availability at synaptic membranes and stabilizing spine actin cytoskeleton and that these constraints can be alleviated by activity-dependent degradation of Tiam1. These findings reveal a previously unknown mechanism restricting hippocampal synaptic plasticity and highlight Tiam1 as a therapeutic target for enhancing cognitive function., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 the authors.)

Voluntary movement, motivation, and reinforcement learning depend on the activity of ventral midbrain neurons, which extend axons to release dopamine (DA) in the striatum. These neurons exhibit two patterns of action potential activity: low-frequency tonic activity that is intrinsically generated and superimposed high-frequency phasic bursts that are driven by synaptic inputs. Ex vivo acute striatal brain preparations are widely employed to study the regulation of evoked DA release but exhibit very different DA release kinetics than in vivo recordings. To investigate the relationship between phasic and tonic neuronal activity, we stimulated the slice in patterns intended to mimic tonic activity, which were interrupted by a series of burst stimuli. Conditioning the striatal slice with low-frequency activity altered DA release triggered by high-frequency bursts and produced kinetic parameters that resemble those in vivo . In the absence of applied tonic activity, nicotinic acetylcholine receptor and D2 DA receptor antagonists had no significant effect on neurotransmitter release, driven by repeated burst activity in the striatal brain slice. In contrast, in tonically stimulated slices, the D2 receptor blockade decreased the amount of DA released during a single-burst and facilitated DA release in subsequent bursts. This experimental system provides a means to reconcile the difference in the kinetics of DA release ex vivo and in vivo and provides a novel approach to more accurately emulate pre- and postsynaptic mechanisms that control axonal DA release in vivo .

Pancreatic ductal adenocarcinoma (PDAC) remains an aggressive malignancy. The occurrence of perineural invasion is associated with neuropathic pain and poor prognosis of PDAC, underscoring the active participation of nerves and their potential as therapeutic targets. Lidocaine is a local anesthetic with antitumor properties in some tumors in the clinic. Nevertheless, its clinical application in PDAC is constrained by the insufficient tumor accumulation and potential neurovirulence associated with a high-dose regimen. Here, a tumor microenvironment-targeted and -responsive liposome was constructed to deliver lidocaine for restraining PDAC growth through single nerve regulation. By conjugation of a collagen binding peptide, the pH-responsive liposomes accumulate in the extracellular matrix. The released lidocaine selectively reduces neurite length and density, thereby indirectly halting the progression and metastasis of PDAC in an orthotopic mouse model without noticeable adverse effects. This study highlights the potential of anesthetic-based nanomodulation of crosstalk between nerve and tumor cells for PDAC treatment.

This study examines the effects of incorporating serotonin (5-HT) into proteinoid microspheres. It looks at the microspheres' structure and electrochemical properties. Proteinoid-serotonin assemblies have better symmetry and membrane organization than pristine proteinoids. Cyclic voltammetry shows a big boost in electron transfer. This is proven by a smaller peak separation and higher electrochemical efficiency. SEM imaging shows a distinct core-shell structure and uniform density. This suggests ordered molecular assembly. These findings show that serotonin changes proteinoid self-assembly. It creates structured systems with better electron transfer pathways. The serotonin-modified proto-neurons show new properties. They give insights into early cellular organization and signaling. This helps us understand prebiotic information processing systems.

Substance-induced social behavior deficits dramatically worsen the clinical outcome of substance use disorders; yet, the underlying mechanisms remain poorly understood. Herein, we investigated the role for the corticotropin-releasing factor receptor 1 (CRF 1 ) in the acute sociability deficits induced by morphine and the related activity of oxytocin (OXY)- and arginine-vasopressin (AVP)-expressing neurons of the paraventricular nucleus of the hypothalamus (PVN). For this purpose, we used both the CRF 1 receptor-preferring antagonist compound antalarmin and the genetic mouse model of CRF 1 receptor-deficiency. Antalarmin completely abolished sociability deficits induced by morphine in male, but not in female, C57BL/6J mice. Accordingly, genetic CRF 1 receptor-deficiency eliminated morphine-induced sociability deficits in male mice. Ex vivo electrophysiology studies showed that antalarmin also eliminated morphine-induced firing of PVN neurons in male, but not in female, C57BL/6J mice. Likewise, genetic CRF 1 receptor-deficiency reduced morphine-induced firing of PVN neurons in a CRF 1 gene expression-dependent manner. The electrophysiology results consistently mirrored the behavioral results, indicating a link between morphine-induced PVN activity and sociability deficits. Interestingly, in male mice antalarmin abolished morphine-induced firing in neurons co-expressing OXY and AVP, but not in neurons expressing only AVP. In contrast, in female mice antalarmin did not affect morphine-induced firing of neurons co-expressing OXY and AVP or only OXY, indicating a selective sex-specific role for the CRF 1 receptor in opiate-induced PVN OXY activity. The present findings demonstrate a major, sex-linked, role for the CRF 1 receptor in sociability deficits and related brain alterations induced by morphine, suggesting new therapeutic strategy for opiate use disorders., Competing Interests: AP, AA, JB, SB, AC No competing interests declared, (© 2024, Piccin et al.)

The nervous system is highly dependent on the supply of oxygen and nutrients, so when demand for oxygen exceeds its supply, hypoxia is induced. The hippocampus is very important in the nervous system. It has the ability to control human behavior, memory, emotion, and so on. Therefore, when the hippocampus is damaged by hypoxia, it may cause nervous system diseases such as Alzheimer's disease, Parkinson's disease, and stroke. Alternative splicing plays an important regulatory role in the processes of growth and disease occurrence and development. However, the function of hypoxia-induced alternative splicing in neurological diseases needs to be further studied. Therefore, we performed hypoxia stress on mouse hippocampal neuron HT22 cells and then analyzed differentially expressed genes and differential alternative splicing events by next-generation sequencing. Through bioinformatics analysis and verification, it was found that hypoxia stress regulated the expression of Rbm15 and the ratio of Dicer1 transcripts in HT22 cells. The change in the ratio of Dicer1 transcripts may be related to the upregulation of miR-29b under hypoxia stress. This study can provide multiple time point sequencing results and a theoretical basis for the study of hypoxia-related gene alternative splicing., (© The Author(s) 2025. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

Aluminum is a well-known and widely distributed environmental neurotoxin. This study aimed to investigate the effect of miR-98-5p targeting insulin-like growth factor 2 (IGF2) on aluminum neurotoxicity. Thirty-two Sprague-Dawley rats were randomly divided into four groups and administered 0, 10, 20, and 40 μmol/kg maltol aluminum [Al(mal) 3 ], respectively. They were intraperitoneally injected every other day for three months. PC12 cells were divided into four dose groups: 0, 100, 200, and 400 μmol/L Al(mal) 3 , and four intervention groups: inhibitor NC, Al(mal) 3 + inhibitor NC, miR-98-5p inhibitor, and Al(mal) 3 + miR-98-5p inhibitor. The Morris water maze was used to test the learning and memory abilities of rats. Hematoxylin and eosin staining was used to observe the arrangement and quantity of neurons in the CA1 area of the rat hippocampus. Cell viability was detected using the Cell Counting Kit-8. Cell apoptosis was detected using flow cytometry and the 5-ethynyl-2'-deoxyuridine assay. Real-time polymerase chain reaction and Western blotting were used to detect the expression levels of miR-98-5p, IGF2 mRNA, IGF2/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway proteins, and apoptosis-related proteins caspase3 and cleaved caspase3. The dual-luciferase assay was used to determine the targeting relationship between miR-98-5p and IGF2 mRNA. As the dose of aluminum exposure increased, the escape latency of rats gradually prolonged, and the target quadrant residence time and the number of crossing platforms gradually decreased. The arrangement of neurons in the hippocampal CA1 area was significantly loose, and their number gradually decreased. The total and early apoptosis rates of PC12 cells gradually increased, and the cell proliferation rate slowed down. Both in vivo and in vitro experimental results showed that with the increase of aluminum exposure dose, the relative expression levels of miR-98-5p and caspase3 and cleaved caspase3 proteins gradually increased, while the relative expression levels of IGF2 mRNA and IGF2, p-JAK2 (Tyr1007/1008), and p-STAT3 (Tyr705) proteins gradually decreased. After inhibiting miR-98-5p in the aluminum exposure group, the cell apoptosis rate and expression of apoptosis-related proteins decreased, and the expression of IGF2 mRNA and IGF2/JAK2/STAT3 proteins increased. These results indicate that miR-98-5p plays a vital role in aluminum-induced neurotoxicity by targeting IGF2.

Neurons in the CNS lose regenerative potential with maturity, leading to minimal corticospinal tract (CST) axon regrowth after spinal cord injury (SCI). In young rodents, knockdown of PTEN, which antagonizes PI3K signaling by hydrolyzing PIP3, promotes axon regeneration following SCI. However, this effect diminishes in adults, potentially due to lower PI3K activation leading to reduced PIP3. This study explores whether increased PIP3 generation can promote long-distance regeneration in adults. We used a hyperactive PI3K, PI3Kδ (PIK3CD), to boost PIP3 levels in mature cortical neurons and assessed CST regeneration after SCI. Adult rats received AAV1-PIK3CD and AAV1-eGFP, or AAV1-eGFP alone, in the sensorimotor cortex concurrent with a C4 dorsal SCI. Transduced neurons showed increased pS6 levels, indicating elevated PI3K/Akt/mTOR signaling. CST regeneration, confirmed with retrograde tracing, was evaluated up to 16 weeks post injury. At 12 weeks, ∼100 axons were present at lesion sites, doubling to 200 by 16 weeks, with regeneration indices of 0.1 and 0.2, respectively. Behavioral tests showed significant improvements in paw reaching, grip strength, and ladder-rung walking in PIK3CD-treated rats, corroborated by electrophysiological recordings of cord dorsum potentials and distal flexor muscle electromyography. Thus, PI3Kδ upregulation in adult cortical neurons enhances axonal regeneration and functional recovery post SCI., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

As a central nervous system-specific member of the protein tyrosine phosphatase (PTP) family, the striatal-enriched protein tyrosine phosphatase (STEP) is an attractive drug target for neurodegenerative diseases. Here, we reported the discovery of a series of benzoic acid derivatives as new STEP inhibitors. Among them, compound 14b exhibited good STEP inhibitory activity and displayed selectivity against other PTPs. The neuroprotective activity of compound 14b was evaluated against glutamate-induced oxidative cell death in HT22 cells. Results indicated that compound 14b co-treatment prevented cell death and reduced cellular ROS accumulation. Compound 14b inhibited cell apoptosis by upregulating BCL-2 expression and downregulating BAX and C-caspase3 expression. Moreover, compound 14b was also found to provide neuroprotection to primary cortical neurons after oxygen-glucose deprivation/reoxygenation (OGD/R). Further structural elaboration of compound 14b may provide new drug candidates for neurodegenerative diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

This study aims to investigate the mechanism by which Histidine triad nucleotide-binding protein 1 (HINT1) promotes hippocampal neuronal apoptosis, triggering schizophrenia (SZ)-like behavior in rats. By establishing a rat SZ-like model, we assessed learning, memory, emotional response, and cognitive function through the Morris Water Maze, auditory startle response, and open field tests. HINT1 expression in the hippocampus was analyzed via RT-PCR and Western blot. We also created a HINT1 overexpression model in hippocampal neuronal cells to analyze its effects on cell proliferation and apoptosis. This analysis was conducted using the CCK-8 assay and flow cytometry, along with the quantification of apoptosis-related proteins and neurotrophic factors. Our findings indicated that the SZ-like model rats exhibited diminished learning and memory abilities, altered emotional reactions, and impaired cognitive functions, alongside a notable increase in HINT1 mRNA and protein levels. HINT1 overexpression was observed to inhibit hippocampal neuronal cell proliferation and promote apoptosis, with an increase in the expression of pro-apoptotic proteins and a decrease in neurotrophic factors. These results suggest HINT1's role in the onset and development of SZ-like behavior through its upregulation and induction of apoptosis in hippocampal neuronal cells, underlining its potential as a therapeutic target., Competing Interests: Conflict of interest The authors declare they have no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Emerging studies have identified ferroptosis as a promising therapeutic target, the inhibition of which is hypothesized to mitigate brain injury and subsequent neuronal death following stroke. Zerumbone, a phytochemical sesquiterpene isolated from Zingiber zerumbet Smith, exhibit diverse therapeutic properties across a range of neurological disorders. This study aimed to elucidate the postischemic neuroprotective effects and regulatory impact of zerumbone on ferroptosis-mediated cell death following oxygen‒glucose deprivation/reperfusion (OGD/R) injury. We employed an in vitro OGD/R SH-SY5Y cell model of stroke to evaluate the postischemic neuroprotective effects of zerumbone, a lead molecule identified through literature studies. Moreover, assays were performed to assess how zerumbone affects lipid peroxide levels, intracellular reactive oxygen species (ROS), and mitochondrial membrane integrity. Furthermore, molecular docking simulations were carried out to determine the targets, and western blotting was performed to examine TFR1 protein expression. Zerumbone (0.5 µM) treatment at 1-hour postischemia increased cell viability (72.11 ± 0.98) and mitigated OGD/R-induced ischemic injury. Zerumbone significantly decreased intracellular ROS levels and lipid peroxide production while increasing mitochondrial membrane integrity, suggesting that zerumbone ameliorated OGD/R-induced ischemic injury by inhibiting ferroptosis in vitro. This finding was corroborated by our western blot analysis, which revealed that the antiferroptotic role of zerumbone was distinctly mediated through the downregulation of transferrin receptor 1 (TFR1) protein expression. This communication, for the first time, highlights the feasibility of zerumbone as a promising adjunctive neuroprotective agent against ferroptosis cell death in the context of cerebral stroke. This study lays the groundwork for subsequent in-depth investigations to fully elucidate its therapeutic potential in ischemic stroke treatment., Competing Interests: Declarations. Ethical approval: No ethical approval was needed for the submitted work. Consent to publish: Not applicable. Informed consent: Informed consent was not needed for the submitted work. Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature B.V.)

Ischemic stroke is a leading cause of disability and death worldwide, largely due to its increasing incidence associated with an aging population. This condition results from arterial obstruction, significantly affecting patients' quality of life and imposing a substantial economic burden on healthcare systems. While current treatments primarily focus on the rapid restoration of blood flow through thrombolytic therapy or surgical interventions, a limited understanding of neuronal injury mechanisms hampers the development of more effective treatments.This article explores the interplay among various cell death pathways-necroptosis, apoptosis, autophagy, ferroptosis, and pyroptosis-in the context of ischemic stroke to identify novel therapeutic targets. Each mode of cell death displays unique characteristics and roles post-stroke, and the activation of these pathways may vary across different animal models, complicating the translation of therapeutic strategies to clinical settings. Notably, the interaction between apoptosis and necroptosis is highlighted; inhibiting apoptosis might heighten the risk of necroptosis. Therefore, a balanced regulation of these pathways could promote enhanced neuronal survival.Additionally, we introduce PANoptosis, a form of cell death that encompasses pyroptosis, apoptosis, and necroptosis, emphasizing the complexity and potential therapeutic implications of these interactions. In summary, understanding the relationships among these cell death mechanisms in ischemic stroke is vital for developing new neuroprotective agents. Future research should aim for combinatorial interventions targeting multiple pathways to optimize treatment strategies and improve patient outcomes., Competing Interests: Declarations. Competing Interests: The authors declare no competing interests. Consent to Participate: Informed consent was obtained from all human participants involved in this study. Consent to Publish: All participants have consented to the publication of their data., (© 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The functional architecture of the long-lived neuronal microtubule (MT) cytoskeleton is maintained by various MT-associated proteins (MAPs), most of which are known to bind to the MT outer surface. However, electron microscopy (EM) has long ago revealed the presence of particles inside the lumens of neuronal MTs, of yet unknown identity and function. Here, we use cryogenic electron tomography (cryo-ET) to analyze the three-dimensional (3D) organization and structures of MT lumenal particles in primary hippocampal neurons, human induced pluripotent stem cell-derived neurons, and pluripotent and differentiated P19 cells. We obtain in situ density maps of several lumenal particles from the respective cells and detect common structural features underscoring their potential overarching functions. Mass spectrometry-based proteomics combined with structural modeling suggest that a subset of lumenal particles could be tubulin-binding cofactors (TBCs) bound to tubulin monomers. A different subset of smaller particles, which remains unidentified, exhibits densities that bridge across the MT protofilaments. We show that increased lumenal particle concentration within MTs is concomitant with neuronal differentiation and correlates with higher MT curvatures. Enrichment of lumenal particles around MT lattice defects and at freshly polymerized MT open-ends suggests a MT protective role. Together with the identified structural resemblance of a subset of particles to TBCs, these results hint at a role in local tubulin proteostasis for the maintenance of long-lived neuronal MTs., Competing Interests: Competing interests statement:Wolfgang Baumeister holds additional appointments as an honorary Professor at the Technical University Munich and a Distinguished Professor at ShanghaiTech University and is a member of the Life Science Advisory Board of Thermo Fisher Scientific. Saikat Chakraborty is currently an employee of Thermo Fisher Scientific.

During adolescence, acute stress can modify neuronal excitability in various brain regions, leading to negative behavioral outcomes. However, the impact of chronic stress during adolescence on neuronal responses to acute stimuli remains unclear. To address this, we subjected adolescent mice to 12 days of chronic unpredictable stress (CUS). Anxiety and depressive behaviors were evaluated, along with changes in c-Fos expression, which is one of the most widely used markers of neuronal activation. By comparing c-Fos immunoreactivity between the CUS and control groups both before and after the tail suspension test (TST), we found that adolescent CUS induced depressive behaviors in male mice, but not in female mice. Adolescent CUS primarily affected the excitability of neurons in the infralimbic cortex (IL), the dorsomedial and dorsolateral area of the bed nucleus of the stria terminalis (BNST), and the ventral hippocampus CA3. TST exerted a significant main effect on the density of c-Fos + neurons in the prelimbic cortex (PL), infralimbic cortex (IL), cingulate areas 1 and 2 (Cg1, Cg2), the lateral septum (LS), BNST, and lateral habenular (LHb). Furthermore, the excitability of neurons in the paraventricular thalamic nucleus (PVT) was impacted by sex. These data suggest that adolescent CUS elicits region- and sex-specific modifications in TST-induced c-Fos expression, establishing a theoretical basis for understanding the pathophysiological alterations in mood disorders following adolescent stress., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Spinal cord injury (SCI) remains a formidable challenge in biomedical research, as the silencing of intrinsic regenerative signals in most spinal neurons results in an inability to reestablish neural circuits. In this study, we found that neurons with low axonal regeneration after SCI showed decreased extracellular signal-regulated kinase (ERK) phosphorylation levels. However, the expression of dual specificity phosphatase 26 (DUSP26)─which negatively regulates ERK phosphorylation─was reduced considerably in neurons undergoing spontaneous axonal regeneration. Therefore, we developed a system named F10@MS@UV-HG that integrated a DUSP26-specific inhibitor into reactive oxygen species-responsive nanoparticles and embedded them in photosensitive hydrogels. This system effectively downregulated DUSP26 expression in primary neurons and enhanced ERK phosphorylation, ultimately promoting axonal outgrowth. When transplanted into an SCI mouse model, the system achieved sustained drug release, specifically targeting the DUSP26/ERK/ELK1 pathway in the spinal neurons and facilitating short-term axonal regeneration. Additionally, long-term repair effects─including improved myelination and enhanced motor function─were evident in the SCI mice transplanted with F10@MS@UV-HG. The results suggested that activating ERK signaling by modulating DUSP26 expression in neurons after SCI could effectively promote axonal regeneration and functional recovery. Thus, the developed F10@MS@UV-HG system exhibits enormous potential as a therapeutic approach for patients with SCI.

Introduction: Migraine, a common disorder marked by severe and repetitive headaches, has been linked to the involvement of the NMDA receptor (NMDAR), a receptor responsible for glutamate signaling. Moringa oleifera (M. oleifera), recognized for its anti-inflammatory properties and therapeutic potential in various conditions, has been investigated. This study aims to assess the efficacy and precise mechanisms of M. oleifera for the treatment of migraine, for which evidence is limited., Methods: Rats were stratified into four distinct groups. The control group did not undergo the migraine-induction protocol. Post-induction, the "sumatriptan" group was administered sumatriptan injections, the "treatment" group received oral M. oleifera extract, and the "vehicle" group was provided with oral solvent treatment. Behavioral evaluations encompassing Von Frey's and hot plate assessments, in addition to qPCR analysis targeting Nr2a, Nr2b, Bax, Bcl-2, and Caspase-3, were conducted., Results: Von Fery's and hot plate tests revealed a notable decrease in triggering pressure and temperature within the vehicle group when compared to the other groups (both ps < 0.001). The Nr2a expression levels in both the vehicle and treatment cohorts exhibited significantly higher values than those observed in the control group (p < 0.001, p = 0.001) and the sumatriptan group (p < 0.001, p = 0.002). Conversely, no substantial alterations in Nr2b or Bcl-2 expression levels were observed across the study groups (p = 0.404, p = 0.976). Notably, heightened expressions of Caspase-3 and Bax were evident in the vehicle group relative to the other groups (p = 0.013, p = 0.010)., Conclusions: Moringa oleifera extract appears to mitigate symptoms of migraine by inhibiting apoptosis, suggesting potential efficacy in migraine treatment; however, additional research investigating a wider range of pathways is necessary., Clinical Trial Number: Not applicable., Competing Interests: Declarations. Ethics approval and consent to participate: The entire experimental protocol adhered to the guidelines set forth by the National Institutes of Health (NIH) [22] and was approved by the Ethics Committee of AJA University of Medical Sciences (Ethics code: IR.AJAUMS.REC.1401.040). We confirm that the animals used in this study were not privately owned by another institution, individual, or farm. They were obtained from an established laboratory animal facility for research purposes Consent for publication: All authors declare their consent for the publication of the current manuscript in the journal BMC Neuroscience Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background: Astrocytes are extensively utilized as starting cells for neuronal conversion. Our previous study discovered that a portion of primary cultured mouse neonatal cortical astrocytes can be directly converted into neurons after exposure to a neurogenic induction condition. Recent in vivo studies have demonstrated astrocyte heterogeneity in terms of their developmental origin, molecular profile, physiology, and functional outputs. We hypothesized that the heterogeneity of primary astrocytes in our study could influence their conversion potential., Methods and Results: We performed single-cell RNA sequencing on cells harvested at key time points during in vitro astrocyte-to-neuron conversion, specifically on Day 1 and Day 9. Through single-cell RNA sequencing analysis, we identified several subpopulations of astrocytes, labeled as Astrocyte 1 to Astrocyte 3, based on distinct gene expression patterns. Pseudotime trajectory analysis predicted the existence of three distinct cell states throughout the conversion process. Astrocyte 3 exhibited a higher propensity for neuronal conversion, with proliferation genes like Mki67 being highly expressed. Additionally, several candidate genes were identified as potentially crucial in the conversion process. Astrocyte 3 is considered a unique subtype population of astrocytes., Conclusions: Our investigation underscores the diversity of primary neonatal cortical astrocytes and provides critical insights into the potential for astrocyte-to-neuron conversion, which may be harnessed to enhance the efficiency of this astrocyte-neuron conversion process., Competing Interests: Declarations. Ethical approval: All experimental protocols involving live animals in this study followed the guidelines of the by-laws on experimentation on animals, and were approved by the Ethics Committee for the Use of Animal Subjects of the Tongji University (Approval Code: TJAB04121102). Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature B.V.)

GABABRs are key membrane proteins that continually adapt the excitability of the nervous system. These G-protein coupled receptors are activated by the brain's premier inhibitory neurotransmitter GABA. They are obligate heterodimers composed of GABA-binding GABABR1 and G-protein-coupling GABABR2 subunits. Recently, three variants (G693W, S695I, I705N) have been identified in the gene (GABBR2) encoding for GABABR2. Individuals that harbour any of these variants exhibit severe developmental epileptic encephalopathy and intellectual disability, but the underlying pathogenesis that is triggered in neurons remains unresolved. Using a range of confocal imaging, flow cytometry, structural modelling, biochemistry, live cell Ca2+ imaging of presynaptic terminals, whole-cell electrophysiology of human embryonic kidney (HEK)-293 T cells and neurons and two-electrode voltage clamping of Xenopus oocytes, we have probed the biophysical and molecular trafficking and functional profiles of G693W, S695I and I705N variants. We report that all three point mutations impair neuronal cell surface expression of GABABRs, reducing signalling efficacy. However, a negative effect evident for one variant perturbed neurotransmission by elevating presynaptic Ca2+ signalling. This is reversed by enhancing GABABR signalling via positive allosteric modulation. Our results highlight the importance of studying neuronal receptors expressed in nervous system tissue and provide new mechanistic insights into how GABABR variants can initiate neurodevelopmental disease whilst highlighting the translational suitability and therapeutic potential of allosteric modulation for correcting these deficits., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Mitochondrial malfunction associated with impaired mitochondrial quality control and self-renewal machinery, known as mitophagy, is an under-appreciated mechanism precipitating synaptic loss and cognitive impairments in Alzheimer's disease. Promoting mitophagy has been shown to improve cognitive function in Alzheimer's disease animals. However, the regulatory mechanism was unclear, which formed the aim of this study. Here, we found that a neuron-specific loss of Bcl-2 family member BOK in patients with Alzheimer's disease and APPswe/PS1dE9 (APP/PS1) mice is closely associated with mitochondrial damage and mitophagy defects. We further revealed that BOK is the key to the Parkin-mediated mitophagy through competitive binding to the MCL1/Parkin complex, resulting in Parkin release and translocation to damaged mitochondria to initiate mitophagy. Furthermore, overexpressing bok in hippocampal neurons of APP/PS1 mice alleviated mitophagy and mitochondrial malfunction, resulting in improved cognitive function. Conversely, the knockdown of bok worsened the aforementioned Alzheimer's disease-related changes. Our findings uncover a novel mechanism of BOK signalling through regulating Parkin-mediated mitophagy to mitigate amyloid pathology, mitochondrial and synaptic malfunctions, and cognitive decline in Alzheimer's disease, thus representing a promising therapeutic target., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Understanding the cellular and genetic mechanisms driving human-specific features of cortical development remains a challenge. We generated a cell-type resolved atlas of transcriptome and chromatin accessibility in the developing macaque and mouse prefrontal cortex (PFC). Comparing with published human data, our findings demonstrate that although the cortex cellular composition is overall conserved across species, progenitor cells show significant evolutionary divergence in cellular properties. Specifically, human neural progenitors exhibit extensive transcriptional rewiring in growth factor and extracellular matrix (ECM) pathways. Expression of the human-specific progenitor marker ITGA2 in the fetal mouse cortex increases the progenitor proliferation and the proportion of upper-layer neurons. These transcriptional divergences are primarily driven by altered activity in the distal regulatory elements. The chromatin regions with human-gained accessibility are enriched with human-specific sequence changes and polymorphisms linked to intelligence and neuropsychiatric disorders. Our results identify evolutionary changes in neural progenitors and putative gene regulatory mechanisms shaping primate brain evolution., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Endocytosis, required for the uptake of receptors and their ligands, can also introduce pathological aggregates such as α-synuclein (α-syn) in Parkinson's Disease. We show here the unexpected presence of intrinsically perforated endolysosomes in neurons, suggesting involvement in the genesis of toxic α-syn aggregates induced by internalized preformed fibrils (PFFs). Aggregation of endogenous α-syn in late endosomes and lysosomes of human iPSC-derived neurons (iNs), seeded by internalized α-syn PFFs, caused the death of the iNs but not of the parental iPSCs and non-neuronal cells. Live-cell imaging of iNs showed constitutive perforations in ∼5% of their endolysosomes. These perforations, identified by 3D electron microscopy in iNs and CA1 pyramidal neurons and absent in non-neuronal cells, may facilitate cytosolic access of endogenous α-syn to PFFs in the lumen of endolysosomes, triggering aggregation. Inhibiting the PIKfyve phosphoinositol kinase reduced α-syn aggregation and associated iN death, even with ongoing PFF endolysosomal entry, suggesting that maintaining endolysosomal integrity might afford a therapeutic strategy to counteract synucleinopathies., (© 2024 Sanyal et al.)

Protein arginine methyltransferase 6 (PRMT6) is a well-characterized epigenetic regulator that methylates histone H3 at arginine 2 (H3R2me2a) in both promoter and enhancer regions, thereby modulating transcriptional initiation. We report here that PRMT6 also regulates gene expression at the post-transcriptional level in the neural pluripotent state and during neuronal differentiation of NT2/D1 cells. PRMT6 knockout causes widespread alternative splicing changes in NT2/D1 cells, most frequently cassette exon alterations. Most of the PRMT6-dependent splicing targets are not transcriptionally affected by the enzyme and regulated in an H3R2me2a-independent manner. However, for a small subset of splicing events, the PRMT6-mediated deposition of H3R2me2a overlaps with the splice site, suggesting a potential dual function in both transcriptional and co-/post-transcriptional regulation. The splicing targets of PRMT6 include ribosomal proteins, splicing factors, and chromatin-modifying enzymes such as PRMT4, DNMT3B, and ASH2L, some of which are associated with differentiation decisions. Taken together, our results in NT2/D1 cells show that PRMT6 exerts predominantly H3R2me2a-independent functions in RNA splicing, which may contribute to pluripotency and neuronal identity., (© 2025 Eudenbach et al.)

The pan-neuronally expressed and phylogenetically conserved CUT homeobox gene ceh-44/CUX orchestrates pan-neuronal gene expression throughout the nervous system of Caenorhabditis elegans. As in many other species, including humans, ceh-44/CUX is encoded by a complex locus that also codes for a Golgi-localized protein, called CASP (Cux1 alternatively spliced product) in humans and CONE-1 ("CASP of nematodes") in C. elegans How gene expression from this complex locus is controlled-and, in C. elegans , directed to all cells of the nervous system-has not been investigated. We show here that pan-neuronal expression of CEH-44/CUX is controlled by a pan-neuronal RNA splicing factor, UNC-75, the C. elegans homolog of vertebrate CELF proteins. During embryogenesis, the cone-1&ceh-44 locus exclusively produces the Golgi-localized CONE-1/CASP protein in all tissues, but upon the onset of postmitotic terminal differentiation of neurons, UNC-75/CELF induces the production of the alternative CEH-44/CUX CUT homeobox gene-encoding transcript exclusively in the nervous system. Hence, UNC-75/CELF-mediated alternative splicing not only directs pan-neuronal gene expression but also excludes a phylogenetically deeply conserved golgin from the nervous system, paralleling surprising spatial specificities of another golgin that we describe here as well. Our findings provide novel insights into how all cells in a nervous system acquire pan-neuronal identity features and reveal unanticipated cellular specificities in Golgi apparatus composition., (© 2025 Leyva-Díaz et al.; Published by Cold Spring Harbor Laboratory Press.)

Background: Glutathione (GSH) is a crucial antioxidant in the human brain. Although proton magnetic resonance spectroscopy using the Mescher-Garwood point-resolved spectroscopy sequence is highly recommended, limited literature has measured cortical GSH using this method in major psychiatric disorders., Methods: By combining magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging, we quantified brain GSH and glutamate in the medial prefrontal cortex and precuneus and explored relationships between GSH levels and intrinsic neuronal activity as well as clinical symptoms among healthy control (HC) participants (n = 30), people with major depressive disorder (MDD) (n = 28), and people with obsessive-compulsive disorder (OCD) (n = 28)., Results: GSH concentrations were lower in the medial prefrontal cortex and precuneus in both the MDD and OCD groups than in the HC group. In the HC group, positive correlations were noted between GSH and glutamate levels and between GSH and fractional amplitude of low-frequency fluctuations in both regions. However, while these correlations were absent in both patient groups, there was a weak positive correlation between glutamate and fractional amplitude of low-frequency fluctuations. Moreover, GSH levels were negatively correlated with depressive and compulsive symptoms in MDD and OCD, respectively., Conclusions: These findings suggest that reduced GSH levels and an imbalance between GSH and glutamate could increase oxidative stress and alter neurotransmitter signaling, thereby leading to disruptions in GSH-related neurochemical-neuronal coupling and psychopathologies across MDD and OCD. Understanding these mechanisms could provide valuable insights into the processes that underlie these disorders and potentially become a springboard for future directions and advancing our knowledge of their neurobiological foundations., (Copyright © 2024 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: The cornu ammonis 1 (CA1) region of the hippocampus is a sensitive area that is susceptible to injury caused by cerebral ischemia. High-mobility group box 1 (HMGB1) and phosphorylated c-Jun N-terminal kinase (p-JNK) play important roles in mediating cerebral ischemic injury., Objective: To elucidate the mechanism through which electroacupuncture (EA) via the Baihui (GV20) and Zusanli (ST36) acupoints protects neurons., Methods: A rat model of permanent middle cerebral artery occlusion (pMCAO) was established. Sprague-Dawley rats were divided into four groups: sham-operated control, pMCAO control, EA, and sham-EA (SEA). In the EA and SEA groups, the GV20 and ST36 acupoints were selected for treatment. However, the SEA group was treated only by superficial pricking of the skin at the two acupoints without the application of electricity. Neurological function was assessed using the neurological deficit function score, and neuronal damage was detected through Nissl staining. HMGB1 and p-JNK expression was evaluated using immunohistochemical staining and western blot assays., Results: The behavioural experiments showed that the EA treatment improved the neurological deficits in the pMCAO rats. The Nissl staining results revealed that EA reduced neural tissue damage. The immunohistochemical staining and western blot results showed that EA inhibited HMGB1 and p-JNK overexpression. By contrast, none of these EA effects were observed in the SEA group., Conclusion: EA may reduce ischemia-induced neuronal damage in the hippocampal CA1 region by inhibiting the overexpression of both HMGB1 and p-JNK.

White adipose tissue (WAT) comprises a plethora of cell types beyond adipocytes forming a regulatory network that ensures systemic energy homeostasis. Intertissue communication is facilitated by metabolites and signaling molecules that are spread by vasculature and nerves. Previous works have indicated that WAT responds to environmental cues by adapting the abundance of these 'communication routes'; however, the high intra-tissue heterogeneity questions the informative value of bulk or single-cell analyses and underscores the necessity of whole-mount imaging. The applicability of whole-mount WAT-imaging is currently limited by two factors - (1) methanol-based tissue clearing protocols restrict the usable antibody portfolio to methanol-resistant antibodies and (2) the vast amounts of data resulting from 3D imaging of whole-tissue samples require high computational expertise and advanced equipment. Here, we present a protocol for whole-mount WAT clearing, overcoming the constraints of antibody-methanol sensitivity. Additionally, we introduce TiNeQuant (for 'tissue network quantifier') a Fiji tool for automated 3D quantification of neuron or vascular network density, which we have made freely available. Given TiNeQuants versatility beyond WAT, it simplifies future efforts studying neuronal or vascular alterations in numerous pathologies., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2025. Published by The Company of Biologists.)

Ceramide C16 is a sphingolipid detected at high levels in several neurodegenerative disorders, including multiple sclerosis (MS). It can be generated de novo or from the hydrolysis of other sphingolipids, such as sphingomyelin or through the recycling of sphingosine, in what is known as the salvage pathway. While the myelin damage occurring in MS suggests the importance of the hydrolytic and salvage pathways, the growing interest on the importance of diet in demyelinating disorders, prompted us to investigate the involvement of de novo ceramide C16 synthesis on disease severity. A diet rich in saturated fats such as palmitic acid, as found in many highly processed foods, provides substrates for the ceramide C16 synthetic enzymes ceramide synthase 6 (CERS6) and 5 (CERS5), which are expressed in the central nervous system. Using the experimental autoimmune encephalomyelitis (EAE) model of inflammatory demyelination, we show here that mice with CamK2a+ neuronal specific deletion of both CerS6 and CerS5 show a milder course of EAE than wild type mice, even when fed a diet enriched in palmitic acid. At a cellular level, neurons lacking both CerS6 and CerS5 are protected from the mitochondrial dysfunction arising from exposure to oxidative stress and palmitic acid in the medium. These data underscore the importance of a healthy diet avoiding processed foods for demyelinating disorders and identifies endogenous neuronal synthesis of ceramide C16 as an important determinant of disease severity., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

Neurons migrate in a saltatory manner by repeating two distinct steps: extension of the leading process and translocation of the cell body. The former step is critical for determining the migratory route in response to extracellular guidance cues. In the latter step, neurons must generate robust forces that translocate the bulky soma against mechanical barriers of the surrounding three-dimensional environment. However, the link between the leading process extension and subsequent somal translocation remains unknown. By using the membrane tension sensor Flipper-TR and scanning ion conductance microscopy, we show that leading process extension increases plasma membrane tension. The tension elevation activated the mechanosensitive ion channel Tmem63b and triggered Ca 2+ influx, leading to actomyosin activation at the rear of the cell. Blockade of this signaling pathway disturbed somal translocation, thereby inhibiting neuronal migration in three-dimensional environments. These data suggest that mechanical signaling through plasma membrane tension and mechano-channels links the leading process extension to somal translocation, allowing rapid and saltatory neuronal migration., Competing Interests: Disclosure and competing interests statement. The authors declare no competing interests., (© 2024. The Author(s).)

Rett syndrome (RTT) is a neurological disorder caused by a mutation in the X-linked methyl-CpG binding protein 2 (MECP2), leading to cognitive and motor skill regression. Therapeutic strategies aimed at increasing brain-derived neurotrophic factor (BDNF) levels have been reported; however, BDNF treatment has limitations, including the inability to penetrate the blood-brain barrier, a short half-life, and potential for adverse effects when administered via intrathecal injection, necessitating novel therapeutic approaches. In this study, we focused on the adenosine A 2A receptor (A 2A R), which modulates BDNF and its downstream pathways, and investigated the therapeutic potential of CGS21680, an A 2A R agonist, through in vitro and in vivo studies using R106W RTT model. CGS21680 restored neurite outgrowth, the number of SYN1 + /MAP2 + puncta pairs, genes related to the BDNF-TrkB signaling pathway (Bdnf, TrkB, and Mtor) and neural development (Tuj1 and Syn1), and electrophysiological functions in in vitro RTT primary neurons. Additionally, CGS21680 alleviated neurobehavioral impairments and modulated gene expression in an RTT in vivo model. Our findings suggest that activation of A 2A R via CGS21680 enhances BDNF-TrkB signaling, which in turn activates downstream pathways, ultimately increasing neurite outgrowth and synaptic plasticity, and restoring neurobehavioral clinical symptoms. This is the first study to report the therapeutic effect of CGS21680 in R106W point mutation RTT models, both in vitro and in vivo. These research results suggest that CGS21680 could be a promising therapeutic candidate for the treatment of RTT., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: C-Yoon Kim reports financial support was provided by National Research Foundation of Korea. C-Yoon Kim reports financial support was provided by Ministry of Food and Drug Safety. Jin Kim reports financial support was provided by Soonchunhyang University. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The purpose of the present study is to investigate changes in the kynurenine pathway after intracerebral hemorrhage (ICH) and its effects on ICH-induced injury. The exposure of a primary rat microglial culture to thrombin increased the mRNA level of kynurenine 3-monooxygenase (KMO), and this increase was attenuated by a p38 MAPK inhibitor. Thrombin also increased the protein level of KMO. In the cultured medium, the ratio of quinolinic acid (QUIN), an N-methyl-d-aspartate receptor (NMDAR) agonist, to kynurenic acid (KYNA), its antagonist, increased. The increase in the QUIN/KYNA ratio was blocked by Ro61-8048, a KMO inhibitor. The mRNA expression of KMO increased in an in vivo murine ICH model. Immunohistochemical staining showed that increased KMO co-localized with neurons, microglia, and astrocytes. The QUIN/KYNA ratio increased after ICH but was blocked by Ro61-8048 or clodronate, a microglia toxin. Ro61-8048 ameliorated brain edema; however, this effect was masked by MK-801, an NMDAR antagonist. Ro61-8048 protected against neuron loss in the perihematomal region and repaired neurological deficits assessed using the corner turn and pole tests. In conclusion, thrombin-induced changes in KMO in microglia mainly and intermediary metabolites of the kynurenine pathway appear to play crucial roles in neuronal injury after ICH., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Development of neuronal connections is spatially and temporally controlled by extracellular cues which often activate their cognate cell surface receptors and elicit localized cellular responses. Here, we demonstrate the use of an optogenetic tool to activate receptor signaling locally to induce actin-mediated growth cone remodeling in neurons. Based on the light-induced interaction between Cryptochrome 2 (CRY2) and CIB1, we generated a bicistronic vector to co-expresses CRY2 fused to the intracellular domain of a guidance receptor and a membrane-anchored CIB1. When expressed in primary neurons, activation of the growth inhibitory PlexA4 receptor induced growth cone collapse, while activation of the growth stimulating TrkA receptor increased growth cone size. Moreover, local activation of either receptor not only elicited the predicted response in light-activated growth cones but also an opposite response in neighboring no-light-exposed growth cones of the same neuron. Finally, this tool was used to reorient growth cones toward or away from the site of light activation and to stimulate local actin polymerization for branch initiation along axonal shafts. These studies demonstrate the use of an optogenetic tool for precise spatial and temporal control of receptor signaling in neurons and support its future application in investigating cellular mechanisms of neuronal development and plasticity., Competing Interests: Conflict of interest: The authors declare no financial conflict of interest.

Loss of function in the subunits of the GTPase-activating protein (GAP) activity toward Rags-1 (GATOR1) complex, an amino-acid sensitive negative regulator of the mechanistic target of rapamycin complex 1 (mTORC1), is implicated in both genetic familial epilepsies and Neurodevelopmental Disorders (NDDs) (Baldassari et al., 2018). Previous studies have found seizure phenotypes and increased activity resulting from conditional deletion of GATOR1 function from forebrain excitatory neurons (Yuskaitis et al., 2018; Dentel et al., 2022); however, studies focused on understanding mechanisms contributing to NDD-relevant behaviors are lacking, especially studies understanding the contributions of GATOR1's critical GAP catalytic subunit, nitrogen permease regulator like-2 (Nprl2). Given the clinical phenotypes observed in patients with Nprl2 mutations, in this study, we sought to investigate the neuronal cell type contributions of Nprl2 to NDD behaviors. We conditionally deleted Nprl2 broadly in most neurons (Synapsin1 cre ), in inhibitory neurons only (Vgat cre ), and in Purkinje cells within the cerebellum (L7 cre ). Broad neuronal deletion of Nprl2 resulted in seizures, social and learning deficits, and hyperactivity. In contrast, deleting Nprl2 from inhibitory neurons led to increased motor learning, hyperactive behavior, in addition to social and learning deficits. Lastly, Purkinje cell (PC) loss of Nprl2 also led to learning and social deficits but did not affect locomotor activity. These phenotypes enhance understanding of the spectrum of disease found in human populations with GATOR1 loss of function and highlight the significance of distinct cellular populations to NDD-related behaviors. SIGNIFICANCE STATEMENT: We aim to elucidate the neuronal-specific contributions of nitrogen permease regulator like-2 (Nprl2) to its neurodevelopmental disorder (NDD)-relevant phenotypes. We conditionally deleted Nprl2 broadly in neurons (Syn1 cre ), in inhibitory neurons (Vgat cre ), and in cerebellar Purkinje cells (L7 cre ). We identify seizures only in the Syn1 cre conditional mutant (cKO); hyperactivity, learning difficulties, social deficits, and impulsivity in the Syn1 cre and Vgat cre cKOs; and social deficits, and fear learning deficits in L7 cre cKOs. To our knowledge, we are the first to describe the behavioral contributions of Nprl2's function across multiple cell types. Our findings highlight both critical roles for Nprl2 in learning and behavior and also distinct contributions of select neuronal populations to these NDD-relevant behaviors., Competing Interests: Declaration of competing interest B.D., L.A.P., A.Y.F., K.L, C.R., A.P.S. have nothing to declare. P.T.T. declares that he is a member of the Raynor Cerebellum Project Advisory Board. He is also a member of the TSC Alliance TSC Preclinical Consortium. Both are unpaid, advisory roles., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Cerebrospinal fluid-contacting neurons (CSF-cNs) exhibit neural stem cell (NSC) properties both in vitro and in vivo, and they may play a critical role in recovery after spinal cord injury (SCI). GABA B receptors (GABABRs) are expressed in Pkd2l1 + CSF-cNs. However, their role in Pkd2l1 + CSF-cNs still needs to be discovered. In this study, we observed a significant reduction in GABA B R expression in a murine model 7 d after SCI. We further discovered that GABA B R activation enhanced the proliferation of Pkd2l1 + CSF-cNs while inhibiting apoptosis. Additionally, this activation mitigated vacuole loss and neuronal damage in the pericentral canal region of the spinal cord, attenuated myelin and axonal loss within the spinal cord, and facilitated motor function recovery in SCI model mice. Mechanistically, GABA B R primed quiescent Pkd2l1 + CSF-cNs for cell cycle reentry through the activation of PI3K/Akt signaling. Our findings suggest that GABA B R activation enhances the NSC potential of Pkd2l1 + CSF-cNs, ultimately enabling post-SCI recovery in murine models., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Store-operated Ca2+ entry (SOCE) is a widespread mechanism of cellular Ca2+ signaling that arises from Ca2+ influx across the plasma membrane through the Orai family of calcium channels in response to depletion of intracellular Ca2+ stores. Orai channels are a crucial Ca2+ entry mechanism in both neurons and glia and are activated by a unique inside-out gating process involving interactions with the endoplasmic reticulum Ca2+ sensors, STIM1 and STIM2. Recent evidence indicates that SOCE is broadly found across all areas of the nervous system where its physiology and pathophysiology is only now beginning to be understood. Here, we review the growing literature on the mechanisms of SOCE in the nervous system and contributions to gene expression, neuronal excitability, synaptic plasticity, and behavior. We also explore the burgeoning links between SOCE and neurological disease and discuss therapeutic implications of targeting SOCE for brain disorders.

Obesity is a prevalent metabolic disorder linked to insulin resistance, hyperglycemia, increased adiposity, chronic inflammation, and cognitive dysfunction. Recent research has focused on developing therapeutic strategies to mitigate cognitive impairment associated with obesity. Insulin growth factor-1 (IGF1) deficiency is linked to insulin resistance, glucose intolerance, and the progression of obesity-related central nervous system (CNS) disorders. In this study, we investigated the neuroprotective effects of IGF1 in two obesity models: diet-induced obesity (high-fat diet mice) and genetic obesity (ob/ob mice which is genetically deficient in leptin), and in vitro Neuro2A neuronal cells and primary cortical neurons under insulin resistance conditions. We performed RNA sequencing analysis using the cortex of high-fat diet mice injected with IGF1. Also, we detected cytokine levels in blood of high-fat diet mice injected with IGF1. In addition, we conducted the Barnes maze test as a spatial memory function test and open field test as an anxiety behavior test in ob/ob mice. We measured the levels of proteins and mRNAs related to insulin signaling, including synaptic density proteins in brain cortex of ob/ob mice. Our results showed that IGF1 injection enhanced spatial memory function and synaptic plasticity in obese mice. Furthermore, in vitro data demonstrated that IGF1 treated neurons revealed enhanced neural complexity and improved neurite outgrowth under insulin resistance condition through the AKT-GSK3β-BDNF pathway related to antidepressant, cognitive function and anti-apoptotic mechanisms. Therefore, our results provided that IGF1 have potential to alleviate cognitive impairment by promoting synaptic plasticity and neural complexity in the obese brain., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2025 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objective: This study aimed to investigate the effect of 20(R)-ginsenoside Rg3 on autophagy induced by cerebral ischemia‒reperfusion injury (CIRI) in rats and explore its regulation of the PI3K/Akt signaling pathway., Methods: Middle cerebral artery occlusion/reperfusion (MCAO/R) in male rats was injected intraperitoneally with 20(R)-ginsenoside Rg3 (5, 10, 20 mg/kg) 12 h before modeling, 2 h after ischemia and 12 h after reperfusion. Neurobehavioral and neuronal morphological changes were detected 24 h after brain I/R. In vitro, the OGD/R-induced injury model is replicated in PC12 cells and different concentrations of 20(R)-ginsenoside Rg3 are administered to observe its effects on cell viability and autophagy and PI3K/Akt/mTOR-related protein expression., Results: Our findings suggest that treatment with 20 mg/kg 20(R)-ginsenoside Rg3 significantly attenuated the neuronal injury, as evidenced by a decreased number of damaged neurons, reduced dissolution of Nissl corpuscles, a fewer autophagosomes, and downregulated expression of Beclin1 and LC3-II/I compared with the MCAO/R group. Furthermore, 20(R)-ginsenoside Rg3 treatment significantly upregulated the expression of p62, p-PI3K, p-AKT, and p-mTOR. In vitro, 20(R)-ginsenoside Rg3 significantly improved the survival rate of cells following OGD/R and markedly attenuated the LY294002 and OGD/R-induced upregulation of Beclin1 and LC3 gene expression. Moreover, 20(R)-ginsenoside Rg3 could rescued the LY294002 and OGD/R-induced downregulation of p62, p-PI3K, p-AKT, and p-mTOR expression., Conclusions: 20(R)-ginsenoside Rg3 attenuates neuronal injury and motor dysfunction following ischemia-reperfusion by inhibiting the activation of autophagy, and its mechanism is related to the upregulation of the PI3K/Akt/mTOR signaling pathway., Competing Interests: Declaration of competing interest No conflicts of interest are declared by the authors., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: As a prevalent cerebrovascular disorder, cerebral infarction (CI) has garnered extensive attention globally due to its high incidence and substantial fatality rate. Ischemia-reperfusion injury (IRI) exacerbates not only neuronal demise but also amplifies neural functional impairment. Tanshinone IIA (Tan IIA) has been identified to confer protection against IRI, yet the precise underlying mechanisms remain elusive. This work aimed to delve into the mechanistic role of Tan IIA in CI, with the goal of furnishing more distinct theoretical substantiation for its clinical application., Methods: Initially, a middle cerebral artery embolization model group (MCAO) model was established, followed by the categorization of rats into distinct groups based on different administration modes. Therapeutic effects were evaluated through indices including mortality rate, cerebral tissue water content, CI proportion, and neural functional scoring. Meanwhile, cellular apoptosis rates in hippocampal and cortical tissues, as well as levels of oxidative stress molecules (OSM), Sirtuin 1 (SIRT1), Forkhead box O3 (FOXO3α), and inflammatory factors, were examined to explore the mechanism of action., Results: This work revealed that within varying doses of Tan IIA groups, as dosage escalated, mortality rate, cerebral edema severity, CI proportion, and neural functional scoring gradually diminished. Notably, the 35 mg/kg dose group exhibited the most significant reductions, with decreases of 74.9%, 12.7%, 47.5%, and 54%, respectively. Cellular apoptosis rates in hippocampal and cortical tissues displayed a stepwise descending trend, with the 35 mg/kg dose group showcasing the largest reduction. SIRT1 and FOXO3α proteins exhibited a steady increase, with the 35 mg/kg dose group manifesting respective elevations of 87.9% and 65.5%, the highest among all groups. Antioxidant molecules glutathione (GSH) and superoxide dismutase (SOD) contents progressively increased, whereas malondialdehyde (MDA) and nitric oxide (NO) content decreased. The 35 mg/kg dose group recorded the highest increments of 49.1% and 58.1% for GSH and SOD content, while achieving the greatest reductions of 55.6% and 56.2% for MDA and NO content. Expression of inflammatory factors, namely tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and interleukin-6 (IL-6), gradually declined, with reductions of 42.1%, 32.2%, and 29.1%, respectively, in the 35 mg/kg dose group, exhibiting drastic differences ( p  < 0.05)., Conclusion: In conclusion, this research elucidates that Tan IIA improves cerebral edema and neural function by elevating intracellular expression of SIRT1 and FOXO3α proteins, modulating OSM and inflammatory factors. These findings yielded robust experimental support for the potential use of Tan IIA as a therapeutic agent for CI.

Peroxisomes are essential organelles involved in critical metabolic processes in animals such as fatty acid oxidation, ether phospholipid production and reactive oxygen species detoxification. We have generated transgenic Drosophila melanogaster models expressing fluorescent reporters for the selective autophagy of peroxisomes, a process known as pexophagy. We show that these reporters are colocalized with a peroxisomal marker and that they can reflect pexophagy induction by iron chelation and inhibition by depletion of the core autophagy protein Atg5. Using light sheet microscopy, we have been able to obtain a global overview of pexophagy levels across the entire organism at different stages of development. Tissue-specific control of pexophagy is exemplified by areas of peroxisome abundance but minimal pexophagy, observed in clusters of oenocytes surrounded by epithelial cells where pexophagy is much more evident. Enhancement of pexophagy was achieved by feeding flies with the iron chelator deferiprone, in line with past results using mammalian cells. Specific drivers were used to visualize pexophagy in neurons, and to demonstrate that specific depletion in the larval central nervous system of Hsc70-5, the Drosophila homologue of the chaperone HSPA9/mortalin, led to a substantial elevation in pexophagy.

Vitamin D binding protein (VDBP) is a potential biomarker of major depressive disorder (MDD). This study demonstrates for the first time that VDBP is highly expressed in core emotion-related brain regions of mice susceptible to chronic unpredictable mild stress (CUMS). Specifically, the overexpression of microglia (MG)-derived VDBP in the prelimbic leads to depression-like behavior and aggravates CUMS-induced depressive phenotypes in mice, whereas conditional knockout of MG-derived VDBP can reverse both neuronal damage and depression-like behaviors. Mechanistically, the binding of MG-derived VDBP with the neuronal receptor megalin mediates the downstream SRC signaling pathway, leading to neuronal and synaptic damage and depression-like behaviors. These events may be caused by biased activation of inhibitory neurons and excitatory-inhibitory imbalance. Importantly, this study has effectively identified MG-derived VDBP as a pivotal mediator in the interplay between microglia and neurons via its interaction with the neuronal receptor megalin and intricate downstream impacts on neuronal functions, thus offering a promising therapeutic target for MDD., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Neonatal hypoxic-ischemic encephalopathy (HIE) is a severe neurological injury during infancy, often resulting in long-term cognitive deficits. This study aimed to investigate the neuroprotective effects of Edaravone (EDA), a free radical scavenger, and elucidate the potential role of brain-derived neurotrophic factor (BDNF) in mediating these effects in neonatal HIE rats. Using the Rice-Vannucci model, HIE was induced in neonatal rats, followed by immediate administration of EDA after the hypoxic-ischemic insult. To examine the role of BDNF, a separate group of rats received intrahippocampal injections of a lentiviral vector for BDNF knockdown prior to the induction of HIE and subsequent EDA treatment. Neuronal survival and apoptosis in the hippocampal region were assessed by immunofluorescence and TUNEL staining, respectively. BDNF expression levels in the hippocampus were analysed using enzyme-linked immunosorbent assay (ELISA). Cognitive function was evaluated using the Morris water maze (MWM) and Y maze tests. Results demonstrated that EDA significantly reduced hippocampal neuronal apoptosis and death, increased neuronal survival, and enhanced BDNF expression compared to the control group. However, the therapeutic effects of EDA were mitigated in the BDNF knockdown group, indicating a crucial role of BDNF in mediating the neuroprotective effects of EDA. Behavioural testing confirmed that EDA treatment significantly improved spatial learning and memory abilities in HIE rats, but these improvements were not observed in rats with BDNF knockdown. In conclusion, our study suggests that EDA treatment mitigates hippocampal neuronal death and improves cognitive dysfunction in HIE rats primarily by upregulating BDNF expression. These findings provide experimental support for the potential application of EDA in the treatment of HIE and highlight the essential role of BDNF in neuroprotection and cognitive recovery post-HIE., (© 2025 International Society for Developmental Neuroscience.)

Studies using mitophagy reporter mice have established steady-state landscapes of mitochondrial destruction in mammalian tissues, sparking intense interest in basal mitophagy. Yet how basal mitophagy is modified by healthy aging in diverse brain cell types has remained a mystery. We present a comprehensive spatiotemporal analysis of mitophagy and macroautophagy dynamics in the aging mammalian brain, reporting critical region- and cell-specific turnover trajectories in a longitudinal study. We demonstrate that the physiological regulation of mitophagy in the mammalian brain is cell-specific, dynamic and complex. Mitophagy increases significantly in the cerebellum and hippocampus during midlife, while remaining unchanged in the prefrontal cortex (PFC). Conversely, macroautophagy decreases in the hippocampus and PFC, but remains stable in the cerebellum. We also describe emergent lysosomal heterogeneity, with subsets of differential acidified lysosomes accumulating in the aging brain. We further establish midlife as a critical inflection point for autophagy regulation, which may be important for region-specific vulnerability and resilience to aging. By mapping in vivo autophagy dynamics at the single cell level within projection neurons, interneurons and microglia, to astrocytes and secretory cells, we provide a new framework for understanding brain aging and offer potential targets and timepoints for further study and intervention in neurodegenerative diseases.

Parkinson's disease (PD)-related depression is associated with aberrant neuronal oscillations and 5-hydroxytryptamine (5-HT) neurotransmission in the medial prefrontal cortex (mPFC). Intermittent theta-burst stimulation (iTBS), an updated pattern of high-frequency repetitive transcranial magnetic stimulation, has possible efficacy in PD-related depression. However, whether iTBS alleviates PD-related depression through modulating neuronal oscillations and 5-HT levels in the mPFC has not been determined. In this study, male Sprague-Dawley rats were used to establish a unilateral 6-hydroxydopamine-induced PD model. Then, acute iTBS was applied to the parkinsonian rats, and behavioral, neurochemical, and electrophysiological experiments were performed. We found that the parkinsonian rats exhibited increased immobility time and decreased sucrose preference accompanied by an increase of δ power and a decrease of θ power in the mPFC compared to sham-operated rats. One block of iTBS (1 block-iTBS, 300 stimuli) alleviated depressive-like behaviors in parkinsonian rats and elevated 5-HT levels in the mPFC compared to sham-iTBS. Additionally, it altered neuronal oscillations in the mPFC in the opposite fashion by suppressing the δ rhythm and enhancing the θ and β rhythms compared to sham-iTBS, suggesting that acute iTBS induces hyperactivity in the mPFC. With this iTBS paradigm, we also observed decreased parvalbumin expression in the mPFC, reflecting reduced cortical inhibition. Finally, correlation analyses showed strong correlation between immobility time and θ power after 1 block-iTBS. These findings suggest that the application of acute iTBS in parkinsonian rats produces antidepressant-like effects, which may be associated with elevated 5-HT levels and normalized neuronal oscillations in the mPFC., (© 2025 Wiley Periodicals LLC.)

Almost every facet of our behavior and physiology varies predictably over the course of day and night, anticipating and adapting us to their associated opportunities and challenges. These rhythms are driven by endogenous biological clocks that, when deprived of environmental cues, can continue to oscillate within a period of approximately 1 day, hence circa - dian . Normally, retinal signals synchronize them to the cycle of light and darkness, but disruption of circadian organization, a common feature of modern lifestyles, carries considerable costs to health. Circadian timekeeping pivots around a cell-autonomous molecular clock, widely expressed across tissues. These cellular timers are in turn synchronized by the principal circadian clock of the brain: the hypothalamic suprachiasmatic nucleus (SCN). Intercellular signals make the SCN network a very powerful pacemaker. Previously, neurons were considered the sole SCN timekeepers, with glial cells playing supportive roles. New discoveries have revealed, however, that astrocytes are active partners in SCN network timekeeping, with their cell-autonomous clock regulating extracellular glutamate and GABA concentrations to control circadian cycles of SCN neuronal activity. Here, we introduce circadian timekeeping at the cellular and SCN network levels before focusing on the contributions of astrocytes and their mutual interaction with neurons in circadian control in the brain., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

T-2 toxin, a potent environmental pollutant, has been proved to stimulate neuroinflammation, while the connection between T-2 toxin and pyroptosis remain elusive. Dimethyl fumarate (DMF), recently identified as a neuroprotectant and pyroptosis inhibitor, has potential therapeutic applications that are underexplored. Based on present study in vitro and vivo, we demonstrated that T-2 toxin induced the activation of NLRP3-Caspase-1 inflammasome in hippocampal neurons. In addition to proinflammatory mediator overexpression, gasdermin D (GSDMD)-dependently pyroptosis in the mouse hippocampal neuron cell line (HT22) treated by T-2 toxin was determined in our study. Moreover, the palliative effect of knockdown sequence of high mobility group B1 protein (HMGB1) provided more details for T-2 toxin-initiated pyroptosis. Importantly, we confirmed that DMF, as a novel inhibitor of GSDMD, could alleviate pyroptosis induced by T-2 toxin in an GSDMD targeting manner. In summary, our studies exposed the evidence that T-2 toxin could induce NLRP3 inflammasome activation and hippocampal neuronal pyroptosis. More notably, DMF was turn out to be a critical executioner for attenuating GSDMD-mediated pyroptosis. Our data found a new function of DMF and suggested a novel therapy strategy against mycotoxin-triggered neuronal inflammation, which leads to varieties of neurological diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Sleep is of vital importance in our lives, yet we are far from understanding the neuronal networks that control the amount and timing of sleep. There is substantial conservation of known sleep-regulating transmitters, allowing for studies in simpler organisms to lead the way in gaining insight into the organization of sleep control circuits. In Drosophila melanogaster, we recently showed that optogenetic activation of neurons that produce the neuropeptide Y (NPY)-related transmitter short neuropeptide F (sNPF) increases time spent asleep. However, sNPF is expressed in several neuronal populations, and thus it is unknown which of those populations play roles in the sleep-promoting effect. In this study, we addressed this issue using a genetic approach to limit optogenetic activation to subsets of sNPF-expressing neurons. We found that sleep promotion was shorter-lived when cryptochrome (CRY)-positive neurons were excluded from being activated. Pigment-dispersing factor (PDF) neurons were not required for sleep promotion, nor were mushroom body (MB) neurons. Acute reactions to a short, 10-s period of optogenetic activation were largely unchanged by excluding activation of the three neuronal populations mentioned above. Together, these results suggest that clock neurons that are CRY-positive and PDF-negative are important contributors to the long-lasting sleep promotion produced by sNPF neuron activation. However, other neurons targeted by the sNPF-GAL4 driver appear to mediate the more rapid behavioral responses. Future studies will seek to identify these additional sNPF neuron populations and to determine how sNPF-expressing clock neurons act in concert with other neuronal circuits to promote sleep., (© 2025 The Author(s). Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.)

Ischemic stroke is a serious cerebrovascular disease that brings a significant threat to human health. Considerable factors are involved in occurrence of cerebral ischemia. Among them, autophagy is an important intracellular process that is activated after ischemic stroke, which plays a crucial role in maintaining homeostasis and survival of neurons. The fusion of lysosomes with autophagosomes is a key step in autophagic processes. In recent decades, investigations have found that acetylation, a common post-translational modification of proteins, has an important regulatory effect on autophagy. The present article focuses on elucidating mechanism and roles of acetylation in fusion of lysosomes with autophagosomes in neurons after ischemic stroke, to seek novel targets and strategies for deeper understanding of the pathogenesis of ischemic stroke. This review is also to provide clues for clinical treatment of ischemic stroke., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Astrocytes are important regulators of neuronal development and activity. Their activation plays a key role in the response to many central nervous system (CNS) pathologies. However, reactive astrocytes are a double-edged sword as their chronic or excessive activation may negatively impact CNS physiology, for example, via abnormal modulation of synaptogenesis and synapse function. Accordingly, astrocyte activation has been linked to neurodegenerative and neurodevelopmental disorders. Therefore, the attenuation of astrocyte activation may be an important approach for preventing and treating these disorders. Since zinc deficiency has been consistently linked to increased pro-inflammatory signaling, we aimed to identify cellular zinc-dependent signaling pathways that may lead to astrocyte activation using techniques such as immunocytochemistry and protein biochemistry to detect astrocyte GFAP expression, fluorescent imaging to detect oxidative stress levels in activated astrocytes, cytokine profiling, and analysis of primary neurons subjected to astrocyte secretomes. Our results reveal a so far not well-described pathway in astrocytes, the platelet activation factor receptor (PAFR) pathway, as a critical zinc-dependent signaling pathway that is sufficient to control astrocyte reactivity. Low zinc levels activate PAFR signaling-driven crosstalk between astrocytes and neurons, which alters excitatory synapse formation during development in a PAFR-dependent manner. We conclude that zinc is a crucial signaling ion involved in astrocyte activation and an important dietary factor that controls astrocytic pro-inflammatory processes. Thus, targeting zinc homeostasis may be an important approach in several neuroinflammatory conditions., (© 2024 The Author(s). Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.)

Objective: Despite the advances in treatments for multiple sclerosis (MS), unremitting neurodegeneration continues to drive disability and disease progression. Smoldering/slowly expanding lesions (SELs) and dysfunction of the RNA binding protein (RBP) heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) are pathologic hallmarks of MS cortex and intricately tied to disability and neurodegeneration, respectively. We hypothesized that neuronal hnRNP A1 dysfunction contributes to neurodegeneration and is exacerbated by smoldering/SELs in progressive MS., Methods: Neuronal hnRNP A1 pathology (nucleocytoplasmic mislocalization of hnRNP A1) was examined in healthy control and MS brains using immunohistochemistry. MS cases were stratified by severity of hnRNP A1 pathology to examine the link between RBP dysfunction, demyelination, and neurodegeneration., Results: We found that smoldering/SELs were only present within a subset of MS tissues characterized by elevated neuronal hnRNP A1 pathology (MS-A1 high ) in adjacent cortical gray matter. In contrast to healthy controls and MS with low hnRNP A1 pathology (MS-A1 low ), MS-A1 high showed elevated markers of neurodegeneration, including neuronal loss and injury, brain atrophy, axonal loss, and axon degeneration. Additionally, we discovered a subpopulation of morphologically intact neurons lacking expression of NeuN, a neuron-specific RBP, in cortical projection neurons in MS-A1 high cases., Interpretation: hnRNP A1 dysfunction contributes to neurodegeneration and may be exacerbated by smoldering/SELs in progressive MS. The discovery of NeuN-negative neurons suggests that some cortical neurons may only be injured and not lost. By characterizing RBP pathology in MS cortex, this study has important implications for understanding the pathogenic mechanisms driving neurodegeneration, the substrate of disability and disease progression. ANN NEUROL 2025;97:313-328., (© 2024 American Neurological Association.)