Neuronal guidance signaling in neurodegenerative diseases: Key regulators that function at neuron-glia and neuroimmune interfaces

The nervous system processes a vast amount of information, performing computations that underlie perception, cognition, and behavior. During development, neuronal guidance genes, which encode extracellular cues, their receptors, and downstream signal transducers, organize neural wiring to generate the complex architecture of the nervous system. It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system. This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system. Supporting this view, these pathways continue to regulate synaptic connectivity, plasticity, and remodeling, and overall brain homeostasis throughout adulthood. Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders. Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified, emerging evidence points to several common themes, including dysfunction in neurons, microglia, astrocytes, and endothelial cells, along with dysregulation of neuron-microglia-astrocyte, neuroimmune, and neurovascular interactions. In this review, we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions. For instance, recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation. We discuss the challenges ahead, along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases. Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions. Specifically, we examine the crosstalk between neuronal guidance signaling and TREM2, a master regulator of microglial function, in the context of pathogenic protein aggregates. It is well-established that age is a major risk factor for neurodegeneration. Future research should address how aging and neuronal guidance signaling interact to influence an individual's susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.

Innovative gene delivery systems for retinal disease therapy

The human retina, a complex and highly specialized structure, includes multiple cell types that work synergistically to generate and transmit visual signals. However, genetic predisposition or age-related degeneration can lead to retinal damage that severely impairs vision or causes blindness. Treatment options for retinal diseases are limited, and there is an urgent need for innovative therapeutic strategies. Cell and gene therapies are promising because of the efficacy of delivery systems that transport therapeutic genes to targeted retinal cells. Gene delivery systems hold great promise for treating retinal diseases by enabling the targeted delivery of therapeutic genes to affected cells or by converting endogenous cells into functional ones to facilitate nerve regeneration, potentially restoring vision. This review focuses on two principal categories of gene delivery vectors used in the treatment of retinal diseases: viral and non-viral systems. Viral vectors, including lentiviruses and adeno-associated viruses, exploit the innate ability of viruses to infiltrate cells, which is followed by the introduction of therapeutic genetic material into target cells for gene correction. Lentiviruses can accommodate exogenous genes up to 8 kb in length, but their mechanism of integration into the host genome presents insertion mutation risks. Conversely, adeno-associated viruses are safer, as they exist as episomes in the nucleus, yet their limited packaging capacity constrains their application to a narrower spectrum of diseases, which necessitates the exploration of alternative delivery methods. In parallel, progress has also occurred in the development of novel non-viral delivery systems, particularly those based on liposomal technology. Manipulation of the ratios of hydrophilic and hydrophobic molecules within liposomes and the development of new lipid formulations have led to the creation of advanced non-viral vectors. These innovative systems include solid lipid nanoparticles, polymer nanoparticles, dendrimers, polymeric micelles, and polymeric nanoparticles. Compared with their viral counterparts, non-viral delivery systems offer markedly enhanced loading capacities that enable the direct delivery of nucleic acids, mRNA, or protein molecules into cells. This bypasses the need for DNA transcription and processing, which significantly enhances therapeutic efficiency. Nevertheless, the immunogenic potential and accumulation toxicity associated with non-viral particulate systems necessitates continued optimization to reduce adverse effects in vivo . This review explores the various delivery systems for retinal therapies and retinal nerve regeneration, and details the characteristics, advantages, limitations, and clinical applications of each vector type. By systematically outlining these factors, our goal is to guide the selection of the optimal delivery tool for a specific retinal disease, which will enhance treatment efficacy and improve patient outcomes while paving the way for more effective and targeted therapeutic interventions.

Neuromodulation techniques for modulating cognitive function: Enhancing stimulation precision and intervention effects

Neuromodulation techniques effectively intervene in cognitive function, holding considerable scientific and practical value in fields such as aerospace, medicine, life sciences, and brain research. These techniques utilize electrical stimulation to directly or indirectly target specific brain regions, modulating neural activity and influencing broader brain networks, thereby regulating cognitive function. Regulating cognitive function involves an understanding of aspects such as perception, learning and memory, attention, spatial cognition, and physical function. To enhance the application of cognitive regulation in the general population, this paper reviews recent publications from the Web of Science to assess the advancements and challenges of invasive and non-invasive stimulation methods in modulating cognitive functions. This review covers various neuromodulation techniques for cognitive intervention, including deep brain stimulation, vagus nerve stimulation, and invasive methods using microelectrode arrays. The non-invasive techniques discussed include transcranial magnetic stimulation, transcranial direct current stimulation, transcranial alternating current stimulation, transcutaneous electrical acupoint stimulation, and time interference stimulation for activating deep targets. Invasive stimulation methods, which are ideal for studying the pathogenesis of neurological diseases, tend to cause greater trauma and have been less researched in the context of cognitive function regulation. Non-invasive methods, particularly newer transcranial stimulation techniques, are gentler and more appropriate for regulating cognitive functions in the general population. These include transcutaneous acupoint electrical stimulation using acupoints and time interference methods for activating deep targets. This paper also discusses current technical challenges and potential future breakthroughs in neuromodulation technology. It is recommended that neuromodulation techniques be combined with neural detection methods to better assess their effects and improve the accuracy of non-invasive neuromodulation. Additionally, researching closed-loop feedback neuromodulation methods is identified as a promising direction for future development.

Metabolic reprogramming of astrocytes: Emerging roles of lactate

Lactate serves as a key energy metabolite in the central nervous system, facilitating essential brain functions, including energy supply, signaling, and epigenetic modulation. Moreover, it links epigenetic modifications with metabolic reprogramming. Nonetheless, the specific mechanisms and roles of this connection in astrocytes remain unclear. Therefore, this review aims to explore the role and specific mechanisms of lactate in the metabolic reprogramming of astrocytes in the central nervous system. The close relationship between epigenetic modifications and metabolic reprogramming was discussed. Therapeutic strategies for targeting metabolic reprogramming in astrocytes in the central nervous system were also outlined to guide future research in central nervous system diseases. In the nervous system, lactate plays an essential role. However, its mechanism of action as a bridge between metabolic reprogramming and epigenetic modifications in the nervous system requires future investigation. The involvement of lactate in epigenetic modifications is currently a hot research topic, especially in lactylation modification, a key determinant in this process. Lactate also indirectly regulates various epigenetic modifications, such as N6-methyladenosine, acetylation, ubiquitination, and phosphorylation modifications, which are closely linked to several neurological disorders. In addition, exploring the clinical applications and potential therapeutic strategies of lactic acid provides new insights for future neurological disease treatments.

Insights into the transcriptomic heterogeneity of brain endothelial cells in normal aging and Alzheimer's disease

Drug development for Alzheimer's disease is extremely challenging, as demonstrated by the repeated failures of amyloid-β-targeted therapeutics and the controversies surrounding the amyloid-β cascade hypothesis. More recently, advances in the development of Lecanemab, an anti-amyloid-β monoclonal antibody, have shown positive results in reducing brain A burden and slowing cognitive decline in patients with early-stage Alzheimer's disease in the Phase III clinical trial (Clarity Alzheimer's disease). Despite these promising results, side effects such as amyloid-related imaging abnormalities (ARIA) may limit its usage. ARIA can manifest as ARIA-E (cerebral edema or effusions) and ARIA-H (microhemorrhages or superficial siderosis) and is thought to be caused by increased vascular permeability due to inflammatory responses, leading to leakages of blood products and protein-rich fluid into brain parenchyma. Endothelial dysfunction is an early pathological feature of Alzheimer's disease, and the blood-brain barrier becomes increasingly leaky as the disease progresses. In addition, APOE4, the strongest genetic risk factor for Alzheimer's disease, is associated with higher vascular amyloid burden, increased ARIA incidence, and accelerated blood-brain barrier disruptions. These interconnected vascular abnormalities highlight the importance of vascular contributions to the pathophysiology of Alzheimer's disease. Here, we will closely examine recent research evaluating the heterogeneity of brain endothelial cells in the microvasculature of different brain regions and their relationships with Alzheimer's disease progression.

Is age-related myelinodegenerative change an initial risk factor of neurodegenerative diseases?

Myelination, the continuous ensheathment of neuronal axons, is a lifelong process in the nervous system that is essential for the precise, temporospatial conduction of action potentials between neurons. Myelin also provides intercellular metabolic support to axons. Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases. In fact, myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases, including multiple sclerosis and Alzheimer's disease. In the central nervous system, compact myelin sheaths are formed by fully mature oligodendrocytes. However, the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages. In addition to their well-known role in action potential propagation, oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes. Therefore, myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases. Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals. In this review, we investigate the changes in myelin that are associated with aging and their underlying mechanisms. We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent, slow down, or even reverse age-related myelin degeneration. Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.

Pathological axonal enlargement in connection with amyloidosis, lysosome destabilization, and bleeding is a major defect in Alzheimer's disease

JOURNAL/nrgr/04.03/01300535-202602000-00047/figure1/v/2025-05-05T160104Z/r/image-tiff Alzheimer's disease is a multi-amyloidosis disease characterized by amyloid-β deposits in brain blood vessels, microaneurysms, and senile plaques. How amyloid-β deposition affects axon pathology has not been examined extensively. We used immunohistochemistry and immunofluorescence staining to analyze the forebrain tissue slices of Alzheimer's disease patients. Widespread axonal amyloidosis with distinctive axonal enlargement was observed in patients with Alzheimer's disease. On average, amyloid-β-positive axon diameters in Alzheimer's disease brains were 1.72 times those of control brain axons. Furthermore, axonal amyloidosis was associated with microtubule-associated protein 2 reduction, tau phosphorylation, lysosome destabilization, and several blood-related markers, such as apolipoprotein E, alpha-hemoglobin, glycosylated hemoglobin type A1C, and hemin. Lysosome destabilization in Alzheimer's disease was also clearly identified in the neuronal soma, where it was associated with the co-expression of amyloid-β, Cathepsin D, alpha-hemoglobin, actin alpha 2, and collagen type IV. This suggests that exogenous hemorrhagic protein intake influences neural lysosome stability. Additionally, the data showed that amyloid-β-containing lysosomes were 2.23 times larger than control lysosomes. Furthermore, under rare conditions, axonal breakages were observed, which likely resulted in Wallerian degeneration. In summary, axonal enlargement associated with amyloidosis, micro-bleeding, and lysosome destabilization is a major defect in patients with Alzheimer's disease. This finding suggests that, in addition to the well-documented neural soma and synaptic damage, axonal damage is a key component of neuronal defects in Alzheimer's disease.

Optogenetic approaches for neural tissue regeneration: A review of basic optogenetic principles and target cells for therapy

Optogenetics has revolutionized the field of neuroscience by enabling precise control of neural activity through light-sensitive proteins known as opsins. This review article discusses the fundamental principles of optogenetics, including the activation of both excitatory and inhibitory opsins, as well as the development of optogenetic models that utilize recombinant viral vectors. A considerable portion of the article addresses the limitations of optogenetic tools and explores strategies to overcome these challenges. These strategies include the use of adeno-associated viruses, cell-specific promoters, modified opsins, and methodologies such as bioluminescent optogenetics. The application of viral recombinant vectors, particularly adeno-associated viruses, is emerging as a promising avenue for clinical use in delivering opsins to target cells. This trend indicates the potential for creating tools that offer greater flexibility and accuracy in opsin delivery. The adaptations of these viral vectors provide advantages in optogenetic studies by allowing for the restricted expression of opsins through cell-specific promoters and various viral serotypes. The article also examines different cellular targets for optogenetics, including neurons, astrocytes, microglia, and Schwann cells. Utilizing specific promoters for opsin expression in these cells is essential for achieving precise and efficient stimulation. Research has demonstrated that optogenetic stimulation of both neurons and glial cells-particularly the distinct phenotypes of microglia, astrocytes, and Schwann cells-can have therapeutic effects in neurological diseases. Glial cells are increasingly recognized as important targets for the treatment of these disorders. Furthermore, the article emphasizes the emerging field of bioluminescent optogenetics, which combines optogenetic principles with bioluminescent proteins to visualize and manipulate neural activity in real time. By integrating molecular genetics techniques with bioluminescence, researchers have developed methods to monitor neuronal activity efficiently and less invasively, enhancing our understanding of central nervous system function and the mechanisms of plasticity in neurological disorders beyond traditional neurobiological methods. Evidence has shown that optogenetic modulation can enhance motor axon regeneration, achieve complete sensory reinnervation, and accelerate the recovery of neuromuscular function. This approach also induces complex patterns of coordinated motor neuron activity and promotes neural reorganization. Optogenetic approaches hold immense potential for therapeutic interventions in the central nervous system. They enable precise control of neural circuits and may offer new treatments for neurological disorders, particularly spinal cord injuries, peripheral nerve injuries, and other neurodegenerative diseases.

Tropism-shifted AAV-PHP.eB-mediated bFGF gene therapy promotes varied neurorestoration after ischemic stroke in mice

JOURNAL/nrgr/04.03/01300535-202602000-00040/figure1/v/2025-05-05T160104Z/r/image-tiff AAV-PHP.eB is an artificial adeno-associated virus (AAV) that crosses the blood-brain barrier and targets neurons more efficiently than other AAVs when administered systematically. While AAV-PHP.eB has been used in various disease models, its cellular tropism in cerebrovascular diseases remains unclear. In the present study, we aimed to elucidate the tropism of AAV-PHP.eB for different cell types in the brain in a mouse model of ischemic stroke and evaluate its effectiveness in mediating basic fibroblast growth factor ( bFGF ) gene therapy. Mice were injected intravenously with AAV-PHP.eB either 14 days prior to (pre-stroke) or 1 day following (post-stroke) transient middle cerebral artery occlusion. Notably, we observed a shift in tropism from neurons to endothelial cells with post-stroke administration of AAV-PHP.eB-mNeonGreen (mNG). This endothelial cell tropism correlated strongly with expression of the endothelial membrane receptor lymphocyte antigen 6 family member A (Ly6A). Furthermore, AAV-PHP.eB-mediated overexpression of bFGF markedly improved neurobehavioral outcomes and promoted long-term neurogenesis and angiogenesis post-ischemic stroke. Our findings underscore the significance of considering potential tropism shifts when utilizing AAV-PHP.eB-mediated gene therapy in neurological diseases and suggest a promising new strategy for bFGF gene therapy in stroke treatment.

Neural circuit mechanisms of epilepsy: Maintenance of homeostasis at the cellular, synaptic, and neurotransmitter levels

Epilepsy, a common neurological disorder, is characterized by recurrent seizures that can lead to cognitive, psychological, and neurobiological consequences. The pathogenesis of epilepsy involves neuronal dysfunction at the molecular, cellular, and neural circuit levels. Abnormal molecular signaling pathways or dysfunction of specific cell types can lead to epilepsy by disrupting the normal functioning of neural circuits. The continuous emergence of new technologies and the rapid advancement of existing ones have facilitated the discovery and comprehensive understanding of the neural circuit mechanisms underlying epilepsy. Therefore, this review aims to investigate the current understanding of the neural circuit mechanisms in epilepsy based on various technologies, including electroencephalography, magnetic resonance imaging, optogenetics, chemogenetics, deep brain stimulation, and brain-computer interfaces. Additionally, this review discusses these mechanisms from three perspectives: structural, synaptic, and transmitter circuits. The findings reveal that the neural circuit mechanisms of epilepsy encompass information transmission among different structures, interactions within the same structure, and the maintenance of homeostasis at the cellular, synaptic, and neurotransmitter levels. These findings offer new insights for investigating the pathophysiological mechanisms of epilepsy and enhancing its clinical diagnosis and treatment.

Topical administration of GLP-1 eyedrops improves retinal ganglion cell function by facilitating presynaptic GABA release in early experimental diabetes

JOURNAL/nrgr/04.03/01300535-202602000-00048/figure1/v/2025-05-05T160104Z/r/image-tiff Diabetic retinopathy is a prominent cause of blindness in adults, with early retinal ganglion cell loss contributing to visual dysfunction or blindness. In the brain, defects in γ-aminobutyric acid synaptic transmission are associated with pathophysiological and neurodegenerative disorders, whereas glucagon-like peptide-1 has demonstrated neuroprotective effects. However, it is not yet clear whether diabetes causes alterations in inhibitory input to retinal ganglion cells and whether and how glucagon-like peptide-1 protects against neurodegeneration in the diabetic retina through regulating inhibitory synaptic transmission to retinal ganglion cells. In the present study, we used the patch-clamp technique to record γ-aminobutyric acid subtype A receptor-mediated miniature inhibitory postsynaptic currents in retinal ganglion cells from streptozotocin-induced diabetes model rats. We found that early diabetes (4 weeks of hyperglycemia) decreased the frequency of GABAergic miniature inhibitory postsynaptic currents in retinal ganglion cells without altering their amplitude, suggesting a reduction in the spontaneous release of γ-aminobutyric acid to retinal ganglion cells. Topical administration of glucagon-like peptide-1 eyedrops over a period of 2 weeks effectively countered the hyperglycemia-induced downregulation of GABAergic mIPSC frequency, subsequently enhancing the survival of retinal ganglion cells. Concurrently, the protective effects of glucagon-like peptide-1 on retinal ganglion cells in diabetic rats were eliminated by topical administration of exendin-9-39, a specific glucagon-like peptide-1 receptor antagonist, or SR95531, a specific antagonist of the γ-aminobutyric acid subtype A receptor. Furthermore, extracellular perfusion of glucagon-like peptide-1 was found to elevate the frequencies of GABAergic miniature inhibitory postsynaptic currents in both ON- and OFF-type retinal ganglion cells. This elevation was shown to be mediated by activation of the phosphatidylinositol-phospholipase C/inositol 1,4,5-trisphosphate receptor/Ca 2+ /protein kinase C signaling pathway downstream of glucagon-like peptide-1 receptor activation. Moreover, multielectrode array recordings revealed that glucagon-like peptide-1 functionally augmented the photoresponses of ON-type retinal ganglion cells. Optomotor response tests demonstrated that diabetic rats exhibited reductions in visual acuity and contrast sensitivity that were significantly ameliorated by topical administration of glucagon-like peptide-1. These results suggest that glucagon-like peptide-1 facilitates the release of γ-aminobutyric acid onto retinal ganglion cells through the activation of glucagon-like peptide-1 receptor, leading to the de-excitation of retinal ganglion cell circuits and the inhibition of excitotoxic processes associated with diabetic retinopathy. Collectively, our findings indicate that the γ-aminobutyric acid system has potential as a therapeutic target for mitigating early-stage diabetic retinopathy. Furthermore, the topical administration of glucagon-like peptide-1 eyedrops represents a non-invasive and effective treatment approach for managing early-stage diabetic retinopathy.

Targeting the brain's glymphatic pathway: A novel therapeutic approach for cerebral small vessel disease

Cerebral small vessel disease encompasses a group of neurological disorders characterized by injury to small blood vessels, often leading to stroke and dementia. Due to its diverse etiologies and complex pathological mechanisms, preventing and treating cerebral small vessel vasculopathy is challenging. Recent studies have shown that the glymphatic system plays a crucial role in interstitial solute clearance and the maintenance of brain homeostasis. Increasing evidence also suggests that dysfunction in glymphatic clearance is a key factor in the progression of cerebral small vessel disease. This review begins with a comprehensive introduction to the structure, function, and driving factors of the glymphatic system, highlighting its essential role in brain waste clearance. Afterwards, cerebral small vessel disease was reviewed from the perspective of the glymphatic system, after which the mechanisms underlying their correlation were summarized. Glymphatic dysfunction may lead to the accumulation of metabolic waste in the brain, thereby exacerbating the pathological processes associated with cerebral small vessel disease. The review also discussed the direct evidence of glymphatic dysfunction in patients and animal models exhibiting two subtypes of cerebral small vessel disease: arteriolosclerosis-related cerebral small vessel disease and amyloid-related cerebral small vessel disease. Diffusion tensor image analysis along the perivascular space is an important non-invasive tool for assessing the clearance function of the glymphatic system. However, the effectiveness of its parameters needs to be enhanced. Among various nervous system diseases, including cerebral small vessel disease, glymphatic failure may be a common final pathway toward dementia. Overall, this review summarizes prevention and treatment strategies that target glymphatic drainage and will offer valuable insight for developing novel treatments for cerebral small vessel disease.

A single-cell landscape of the regenerating spinal cord of zebrafish

JOURNAL/nrgr/04.03/01300535-202602000-00046/figure1/v/2025-05-05T160104Z/r/image-tiff Unlike mammals, zebrafish possess a remarkable ability to regenerate their spinal cord after injury, making them an ideal vertebrate model for studying regeneration. While previous research has identified key cell types involved in this process, the underlying molecular and cellular mechanisms remain largely unexplored. In this study, we used single-cell RNA sequencing to profile distinct cell populations at different stages of spinal cord injury in zebrafish. Our analysis revealed that multiple subpopulations of neurons showed persistent activation of genes associated with axonal regeneration post injury, while molecular signals promoting growth cone collapse were inhibited. Radial glial cells exhibited significant proliferation and differentiation potential post injury, indicating their intrinsic roles in promoting neurogenesis and axonal regeneration, respectively. Additionally, we found that inflammatory factors rapidly decreased in the early stages following spinal cord injury, creating a microenvironment permissive for tissue repair and regeneration. Furthermore, oligodendrocytes lost maturity markers while exhibiting increased proliferation following injury. These findings demonstrated that the rapid and orderly regulation of inflammation, as well as the efficient proliferation and redifferentiation of new neurons and glial cells, enabled zebrafish to reconstruct the spinal cord. This research provides new insights into the cellular transitions and molecular programs that drive spinal cord regeneration, offering promising avenues for future research and therapeutic strategies.

Sox2-overexpressing neural stem cells alleviate ventricular enlargement and neurological dysfunction in posthemorrhagic hydrocephalus

JOURNAL/nrgr/04.03/01300535-202602000-00045/figure1/v/2025-05-05T160104Z/r/image-tiff Neural stem cells (NSCs) have the potential for self-renewal and multidirectional differentiation, and their transplantation has achieved good efficacy in a variety of diseases. However, only 1%-10% of transplanted NSCs survive in the ischemic and hypoxic microenvironment of posthemorrhagic hydrocephalus. Sox2 is an important factor for NSCs to maintain proliferation. Therefore, Sox2-overexpressing NSCs (NSCSox2) may be more successful in improving neurological dysfunction after posthemorrhagic hydrocephalus. In this study, human NSCSox2 was transplanted into a posthemorrhagic hydrocephalus mouse model, and retinoic acid was administered to further promote NSC differentiation. The results showed that NSCSox2 attenuated the ventricular enlargement caused by posthemorrhagic hydrocephalus and improved neurological function. NSCSox2 also promoted nerve regeneration, inhibited neuroinflammation and promoted M2 polarization (anti-inflammatory phenotype), thereby reducing cerebrospinal fluid secretion in choroid plexus. These findings suggest that NSCSox2 rescued ventricular enlargement and neurological dysfunction induced by posthemorrhagic hydrocephalus through neural regeneration and modulation of inflammation.

Zebrafish optic nerve regeneration involves resident and retinal oligodendrocytes

JOURNAL/nrgr/04.03/01300535-202602000-00049/figure1/v/2025-05-05T160104Z/r/image-tiff The visual system of teleost fish grows continuously, which is a useful model for studying regeneration of the central nervous system. Glial cells are key for this process, but their contribution is still not well defined. We followed oligodendrocytes in the visual system of adult zebrafish during regeneration of the optic nerve at 6, 24, and 72 hours post-lesion and at 7 and 14 days post-lesion via the sox10:tagRFP transgenic line and confocal microscopy. To understand the changes that these oligodendrocytes undergo during regeneration, we used Sox2 immunohistochemistry, a stem cell marker involved in oligodendrocyte differentiation. We also used the Click-iT™ Plus TUNEL assay to study cell death and a BrdU assay to determine cell proliferation. Before optic nerve crush, sox10:tagRFP oligodendrocytes are located in the retina, in the optic nerve head, and through all the entire optic nerve. Sox2-positive cells are present in the peripheral germinal zone, the mature retina, and the optic nerve. After optic nerve crush, sox10:tagRFP cells disappeared from the optic nerve crush zone, suggesting that they died, although they were not TUNEL positive. Concomitantly, the number of Sox2-positive cells increased around the crushed area, the optic nerve head, and the retina. Then, between 24 hours post-lesion and 14 days post-lesion, double sox10:tagRFP /Sox2-positive cells were detected in the retina, optic nerve head, and whole optic nerve, together with a proliferation response at 72 hours post-lesion. Our results confirm that a degenerating process may occur prior to regeneration. First, sox10:tagRFP oligodendrocytes that surround the degenerated axons stop wrapping them, change their "myelinating oligodendrocyte" morphology to a "nonmyelinating oligodendrocyte" morphology, and die. Then, residual oligodendrocyte progenitor cells in the optic nerve and retina proliferate and differentiate for the purpose of remyelination. As new axons arise from the surviving retinal ganglion cells, new sox10:tagRFP oligodendrocytes arise from residual oligodendrocyte progenitor cells to guide, nourish and myelinate them. Thus, oligodendrocytes play an active role in zebrafish axon regeneration and remyelination.

Recent advances in immunotherapy targeting amyloid-beta and tauopathies in Alzheimer's disease

Alzheimer's disease, a devastating neurodegenerative disorder, is characterized by progressive cognitive decline, primarily due to amyloid-beta protein deposition and tau protein phosphorylation. Effectively reducing the cytotoxicity of amyloid-beta42 aggregates and tau oligomers may help slow the progression of Alzheimer's disease. Conventional drugs, such as donepezil, can only alleviate symptoms and are not able to prevent the underlying pathological processes or cognitive decline. Currently, active and passive immunotherapies targeting amyloid-beta and tau have shown some efficacy in mice with asymptomatic Alzheimer's disease and other transgenic animal models, attracting considerable attention. However, the clinical application of these immunotherapies demonstrated only limited efficacy before the discovery of lecanemab and donanemab. This review first discusses the advancements in the pathogenesis of Alzheimer's disease and active and passive immunotherapies targeting amyloid-beta and tau proteins. Furthermore, it reviews the advantages and disadvantages of various immunotherapies and considers their future prospects. Although some antibodies have shown promise in patients with mild Alzheimer's disease, substantial clinical data are still lacking to validate their effectiveness in individuals with moderate Alzheimer's disease.

Chemical exchange saturation transfer MRI for neurodegenerative diseases: An update on clinical and preclinical studies

Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been extensively studied for diagnosing malignancy and stroke. In recent years, the emerging exploration of chemical exchange saturation transfer magnetic resonance imaging for detecting pathological changes in neurodegenerative diseases has opened up new possibilities for early detection and repetitive scans without ionizing radiation. This review serves as an overview of chemical exchange saturation transfer magnetic resonance imaging with detailed information on contrast mechanisms and processing methods and summarizes recent developments in both clinical and preclinical studies of chemical exchange saturation transfer magnetic resonance imaging for Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Huntington's disease. A comprehensive literature search was conducted using databases such as PubMed and Google Scholar, focusing on peer-reviewed articles from the past 15 years relevant to clinical and preclinical applications. The findings suggest that chemical exchange saturation transfer magnetic resonance imaging has the potential to detect molecular changes and altered metabolism, which may aid in early diagnosis and assessment of the severity of neurodegenerative diseases. Although promising results have been observed in selected clinical and preclinical trials, further validations are needed to evaluate their clinical value. When combined with other imaging modalities and advanced analytical methods, chemical exchange saturation transfer magnetic resonance imaging shows potential as an in vivo biomarker, enhancing the understanding of neuropathological mechanisms in neurodegenerative diseases.

Measuring glymphatic function: Assessing the toolkit

Glymphatic flow has been proposed to clear brain waste while we sleep. Cerebrospinal fluid moves from periarterial to perivenous spaces through the parenchyma, with subsequent cerebrospinal fluid drainage to dural lymphatics. Glymphatic disruption is associated with neurological conditions such as Alzheimer's disease and traumatic brain injury. Therefore, investigating its structure and function may improve understanding of pathophysiology. The recent controversy on whether glymphatic flow increases or decreases during sleep demonstrates that the glymphatic hypothesis remains contentious. However, discrepancies between different studies could be due to limitations of the specific techniques used and confounding factors. Here, we review the methods used to study glymphatic function and provide a toolkit from which researchers can choose. We conclude that tracer analysis has been useful, ex vivo techniques are unreliable, and in vivo imaging is still limited. Finally, we explore the potential for future methods and highlight the need for in vitro models, such as microfluidic devices, which may address technique limitations and enable progression of the field.

Blood-brain barrier disruption and neuroinflammation in the hippocampus of a cardiac arrest porcine model: Single-cell RNA sequencing analysis

JOURNAL/nrgr/04.03/01300535-202602000-00043/figure1/v/2025-05-05T160104Z/r/image-tiff Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality. Despite advancements in resuscitation science, our limited understanding of the cellular and molecular mechanisms underlying post-cardiac arrest brain injury have hindered the development of effective neuroprotective strategies. Previous studies primarily focused on neuronal death, potentially overlooking the contributions of non-neuronal cells and intercellular communication to the pathophysiology of cardiac arrest-induced brain injury. To address these gaps, we hypothesized that single-cell transcriptomic analysis could uncover previously unidentified cellular subpopulations, altered cell communication networks, and novel molecular mechanisms involved in post-cardiac arrest brain injury. In this study, we performed a single-cell transcriptomic analysis of the hippocampus from pigs with ventricular fibrillation-induced cardiac arrest at 6 and 24 hours following the return of spontaneous circulation, and from sham control pigs. Sequencing results revealed changes in the proportions of different cell types, suggesting post-arrest disruption in the blood-brain barrier and infiltration of neutrophils. These results were validated through western blotting, quantitative reverse transcription-polymerase chain reaction, and immunofluorescence staining. We also identified and validated a unique subcluster of activated microglia with high expression of S100A8, which increased over time following cardiac arrest. This subcluster simultaneously exhibited significant M1/M2 polarization and expressed key functional genes related to chemokines and interleukins. Additionally, we revealed the post-cardiac arrest dysfunction of oligodendrocytes and the differentiation of oligodendrocyte precursor cells into oligodendrocytes. Cell communication analysis identified enhanced post-cardiac arrest communication between neutrophils and microglia that was mediated by neutrophil-derived resistin, driving pro-inflammatory microglial polarization. Our findings provide a comprehensive single-cell map of the post-cardiac arrest hippocampus, offering potential novel targets for neuroprotection and repair following cardiac arrest.

Defective exercise-related expiratory muscle recruitment in patients with PHOX2B mutations: A clue to neural determinants of the congenital central hypoventilation syndrome

INTRODUCTION AND OBJECTIVES

The human congenital central hypoventilation syndrome (CCHS) is caused by mutations in the PHOX2B (paired-like homeobox 2B) gene. Genetically engineered PHOX2B rodents exhibit defective development of the brainstem retrotrapezoid nucleus (RTN), a carbon dioxide sensitive structure that critically controls expiratory muscle recruitment. This has been linked to a blunted exercise ventilatory response. Whether this can be extrapolated to human CCHS is unknown and represents the objective of this study.

MATERIALS AND METHODS

Thirteen adult CCHS patients and 13 healthy participants performed an incremental symptom-limited cycle cardiopulmonary exercise test. Responses were analyzed using guideline approaches (ventilation V'E, tidal volume VT, breathing frequency, oxygen consumption, carbon dioxide production) complemented by a breathing pattern analysis (i.e. expiratory and inspiratory reserve volume, ERV and IRV).

RESULTS

A ventilatory response occurred in both study groups, as follows: V'E and VT increased in CCHS patients until 40 W and then decreased, which was not observed in the healthy participants (p<0.001). In the latter, exercise-related ERV and IRV decreases attested to concomitant expiratory and inspiratory recruitment. In the CCHS patients, inspiratory recruitment occurred but there was no evidence of expiratory recruitment (absence of any ERV decrease, p<0.001).

CONCLUSIONS

Assuming a similar organization of respiratory rhythmogenesis in humans and rodents, the lack of exercise-related expiratory recruitment observed in our CCHS patients is compatible with a PHOX2B-related defect of a neural structure that would be analogous to the rodents' RTN. Provided corroboration, ERV recruitment could serve as a physiological outcome in studies aiming at correcting breathing control in CCHS.

Respiratory modulation of beta corticomuscular coherence in isometric hand movements

Respiration is a fundamental physiological function in humans, often synchronized with movement to enhance performance and efficiency. Recent studies have underscored the modulatory effects of respiratory rhythms on brain oscillations and various behavioral responses, including sensorimotor processes. In light of this connection, our study aimed to investigate the influence of different respiratory patterns on beta corticomuscular coherence (CMC) during isometric hand flexion and extension. Utilizing electroencephalogram (EEG) and surface electromyography (sEMG), we examined three breathing conditions: normal breathing, deep inspiration, and deep expiration. Two experimental protocols were employed: the first experiment required participants to simultaneously breathe and exert force, while the other involved maintaining a constant force while varying breathing patterns. The results revealed that deep inspiration significantly enhanced beta CMC during respiration-synchronized tasks, whereas normal breathing resulted in higher CMC compared to deep respiration during sustained force exertion. In the second experiment, beta CMC was cyclically modulated by respiratory phase across all breathing conditions. The difference in the outcomes from the two protocols demonstrated a task-specific modulation of respiration on motor control. Overall, these findings indicate the complex dynamics of respiration-related effects on corticomuscular neural communication and provide valuable insights into the mechanisms underpinning the coupling between respiration and motor function.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-025-10245-x.

Biomaterial-based strategies: a new era in spinal cord injury treatment

Enhancing neurological recovery and improving the prognosis of spinal cord injury have gained research attention recently. Spinal cord injury is associated with a complex molecular and cellular microenvironment. This complexity has prompted researchers to elucidate the underlying pathophysiological mechanisms and changes and to identify effective treatment strategies. Traditional approaches for spinal cord injury repair include surgery, oral or intravenous medications, and administration of neurotrophic factors; however, the efficacy of these approaches remains inconclusive, and serious adverse reactions continue to be a concern. With advancements in tissue engineering and regenerative medicine, emerging strategies for spinal cord injury repair now involve nanoparticle-based nanodelivery systems, scaffolds, and functional recovery techniques that incorporate biomaterials, bioengineering, stem cell, and growth factors as well as three-dimensional bioprinting. Ideal biomaterial scaffolds should not only provide structural support for neuron migration, adhesion, proliferation, and differentiation but also mimic the mechanical properties of natural spinal cord tissue. Additionally, these scaffolds should facilitate axon growth and neurogenesis by offering adjustable topography and a range of physical and biochemical cues. The three-dimensionally interconnected porous structure and appropriate physicochemical properties enabled by three-dimensional biomimetic printing technology can maximize the potential of biomaterials used for treating spinal cord injury. Therefore, correct selection and application of scaffolds, coupled with successful clinical translation, represent promising clinical objectives to enhance the treatment efficacy for and prognosis of spinal cord injury. This review elucidates the key mechanisms underlying the occurrence of spinal cord injury and regeneration post-injury, including neuroinflammation, oxidative stress, axon regeneration, and angiogenesis. This review also briefly discusses the critical role of nanodelivery systems used for repair and regeneration of injured spinal cord, highlighting the influence of nanoparticles and the factors that affect delivery efficiency. Finally, this review highlights tissue engineering strategies and the application of biomaterial scaffolds for the treatment of spinal cord injury. It discusses various types of scaffolds, their integrations with stem cells or growth factors, and approaches for optimization of scaffold design.

Teaching CORnet human fMRI representations for enhanced model-brain alignment

Deep convolutional neural networks (DCNNs) have demonstrated excellent performance in object recognition and have been found to share some similarities with brain visual processing. However, the substantial gap between DCNNs and human visual perception still exists. Functional magnetic resonance imaging (fMRI) as a widely used technique in cognitive neuroscience can record neural activation in the human visual cortex during the process of visual perception. Can we teach DCNNs human fMRI signals to achieve a more brain-like model? To answer this question, this study proposed ReAlnet-fMRI, a model based on the SOTA vision model CORnet but optimized using human fMRI data through a multi-layer encoding-based alignment framework. This framework has been shown to effectively enable the model to learn human brain representations. The fMRI-optimized ReAlnet-fMRI exhibited higher similarity to the human brain than both CORnet and the control model in within- and across-subject as well as within- and across-modality model-brain (fMRI and EEG) alignment evaluations. Additionally, we conducted an in-depth analysis to investigate how the internal representations of ReAlnet-fMRI differ from CORnet in encoding various object dimensions. These findings provide the possibility of enhancing the brain-likeness of visual models by integrating human neural data, helping to bridge the gap between computer vision and visual neuroscience.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-025-10252-y.

Study on the mechanism of Xanthoceras sorbifolia Bunge oil in the treatment of Alzheimer's disease by an integrated "network pharmacology-metabolomics" strategy

BACKGROUND

Xanthoceras sorbifolia Bunge oil (XSBO) has garnered significant interest from researchers due to its distinctive anti-Alzheimer's disease (AD) properties. However, the underlying molecular mechanism remain unclear. This study aims to investigate the potential mechanisms by which XSBO may exert therapeutic effects on AD by employing a combination of network pharmacology analysis and experimental validation.

METHODS

The chemical composition and absorbed compounds of XSBO were identified using GC-MS and LC-MS. Network pharmacology analysis was performed using various computational tools to identify hub genes and construct compound-target-pathway networks. Subsequently, both in vitro and in vivo experiments were conducted to confirm the mechanisms by which XSBO may treat AD.

RESULTS

The results identified 43 active compounds in XSBO, targeting a total of 223 genes, of which 191 were associated with AD. Network analysis indicated that the active constituents in XSBO, such as 9,12-octadecadienoic acid, linoelaidic acid and 11-octadecenoic acid, interact with targets including MAPK1, MAPK3, AKT1, RXRA, RXRB, PPARD and PPARA to modulate inflammation-related signalling pathways and the sphingolipid signalling pathway. In vitro investigations corroborated that XSBO can significantly influence the viability of Aβ25-35-induced SH-SY5Y cells via the MAPK pathway.

CONCLUSIONS

This study demonstrated that XSBO has the potential to mitigate inflammation network disorders through the MAPK pathway and to restore sphingolipid metabolite levels in AD rats, thereby laying a groundwork for future studies.

A stacking classifier for distinguishing stages of Alzheimer's disease from a subnetwork perspective

Accurately distinguishing stages of Alzheimer's disease (AD) is crucial for diagnosis and treatment. In this paper, we introduce a stacking classifier method that combines six single classifiers into a stacking classifier. Using brain network models and network metrics, we employ t-tests to identify abnormal brain regions, from which we construct a subnetwork and extract its features to form the training dataset. Our method is then applied to the ADNI (Alzheimer's Disease Neuroimaging Initiative) datasets, categorizing the stages into four categories: Alzheimer's disease, mild cognitive impairment (MCI), mixed Alzheimer's mild cognitive impairment (ADMCI), and healthy controls (HCs). We investigate four classification groups: AD-HCs, AD-MCI, HCs-ADMCI, and HCs-MCI. Finally, we compare the classification accuracy between a single classifier and our stacking classifier, demonstrating superior accuracy with our stacking classifier from a subnetwork-based viewpoint.

The role of beta band phase resetting in audio-visual temporal order judgment

The integration of auditory and visual stimuli is essential for effective language processing and social perception. The present study aimed to elucidate the mechanisms underlying audio-visual (A-V) integration by investigating the temporal dynamics of multisensory regions in the human brain. Specifically, we evaluated inter-trial coherence (ITC), a neural index indicative of phase resetting, through scalp electroencephalography (EEG) while participants performed a temporal-order judgment task that involved auditory (beep, A) and visual (flash, V) stimuli. The results indicated that ITC phase resetting was greater for bimodal (A + V) stimuli compared to unimodal (A or V) stimuli in the posterior temporal region, which resembled the responses of A-V multisensory neurons reported in animal studies. Furthermore, the ITC got lager as the stimulus-onset asynchrony (SOA) between beep and flash approached 0 ms. This enhancement in ITC was most clearly seen in the beta band (13-30 Hz). Overall, these findings highlight the importance of beta rhythm activity in the posterior temporal cortex for the detection of synchronous audiovisual stimuli, as assessed through temporal order judgment tasks.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-024-10183-0.

Alterations of synaptic plasticity and brain oscillation are associated with autophagy induced synaptic pruning during adolescence

Adolescent brain development is characterized by significant anatomical and physiological alterations, but little is known whether and how these alterations impact the neural network. Here we investigated the development of functional networks by measuring synaptic plasticity and neural synchrony of local filed potentials (LFPs), and further explored the underlying mechanisms. LFPs in the hippocampus were recorded in young (21 ~ 25 days), adolescent (1.5 months) and adult (3 months) rats. Long term potentiation (LTP) and neural synchrony were analyzed. The results showed that the LTP was the lowest in adolescent rats. During development, the theta coupling strength was increased progressively but there was no significant change of gamma coupling between young rats and adolescent rats. The density of dendrite spines was decreased progressively during development. The lowest levels of NR2A, NR2B and PSD95 were detected in adolescent rats. Importantly, it was found that the expression levels of autophagy markers were the highest during adolescent compared to that in other developmental stages. Moreover, there were more co-localization of autophagosome and PSD95 in adolescent rats. It suggests that autophagy is possibly involved in synaptic elimination during adolescence, and further impacts synaptic plasticity and neural synchrony.

Functional abnormalities of the glymphatic system in cognitive disorders

Various pathological mechanisms represent distinct therapeutic targets for cognitive disorders, but a balance between clearance and production is essential for maintaining the stability of the brain's internal environment. Thus, the glymphatic system may represent a common pathway by which to address cognitive disorders. Using the established model of the glymphatic system as our foundation, this review disentangles and analyzes the components of its clearance mechanism, including the initial inflow of cerebrospinal fluid, the mixing of cerebrospinal fluid with interstitial fluid, and the outflow of the mixed fluid and the clearance. Each section summarizes evidence from experimental animal models and human studies, highlighting the normal physiological properties of key structures alongside their pathological manifestations in cognitive disorders. The same pathologic manifestations of different cognitive disorders appearing in the glymphatic system and the same upstream influences are main points of interest of this review. We conclude this article by discussing new findings and outlining the limitations identified in current research progress.

The relationship between childhood trauma, rs1360780 genotypes, FKBP5 intron 7 methylation and posttraumatic stress disorder in women who have experienced rape

Background: Posttraumatic stress disorder (PTSD) is a common sequela of rape. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, a core regulator of the stress response, has been implicated in the aetiology and chronicity of PTSD. FK506 binding protein (FKBP5) is a co-chaperone and functional regulator of the glucocorticoid receptor and the HPA-axis.Objective: This study investigated main and interaction effects of childhood trauma and the FKBP5 rs1360780 genotype on longitudinal FKBP5 intron 7 methylation, and whether change in FKBP5 methylation over time was associated with PTSD symptom severity over time.Method: Women who experienced rape (n = 96) were recruited from post-rape care services in KwaZulu Natal, South Africa. Total PTSD symptom scores, derived from the Davidson Trauma Scale, were assessed at baseline, 3-months and 6-months post-rape. Methylation levels at five FKBP5 intron 7 CpG sites were determined using EpiTYPER Sequenom MassArray technology. Genotyping of rs1360980 was completed using the Agena MassArray genotyping system. Mixed linear regression models were used to analyse the data.Results: The interaction between rs1360780 genotype and childhood trauma was a significant predictor of FKBP5 methylation over time. There was a significant positive correlation between childhood trauma and methylation levels in participants with the CT and TT genotypes, while there was a significant negative correlation between childhood trauma and methylation in CC genotype carriers. FKBP5 methylation was not a predictor of PTSD scores over time.Conclusion: This is the first study to investigate longitudinal change in FKBP5 methylation in a demographically homogenous same-trauma sample. The findings implicate childhood trauma and FKBP5 rs1360980 genotype in the trajectory of FKBP5 methylation levels in the aftermath of rape. Further research is needed to investigate the longitudinal role of FKBP5 intron 7 methylation in relation to PTSD symptom trajectories post-rape.

Gut dysbiosis was inevitable, but tolerance was not: temporal responses of the murine microbiota that maintain its capacity for butyrate production correlate with sustained antinociception to chronic morphine

The therapeutic benefits of opioids are compromised by the development of analgesic tolerance, which necessitates higher dosing for pain management thereby increasing the liability for drug dependence and addiction. Rodent models indicate opposing roles of the gut microbiota in tolerance: morphine-induced gut dysbiosis exacerbates tolerance, whereas probiotics ameliorate tolerance. Not all individuals develop tolerance, which could be influenced by differences in microbiota, and yet no study design has capitalized upon this natural variation. We leveraged natural behavioral variation in a murine model of voluntary oral morphine self-administration to elucidate the mechanisms by which microbiota influences tolerance. Although all mice shared similar morphine-driven microbiota changes that largely masked informative associations with variability in tolerance, our high-resolution temporal analyses revealed a divergence in the progression of dysbiosis that best explained sustained antinociception. Mice that did not develop tolerance maintained a higher capacity for production of the short-chain fatty acid (SCFA) butyrate known to bolster intestinal barriers and promote neuronal homeostasis. Both fecal microbial transplantation (FMT) from donor mice that did not develop tolerance and dietary butyrate supplementation significantly reduced the development of tolerance independently of suppression of systemic inflammation. These findings could inform immediate therapies to extend the analgesic efficacy of opioids.

The roles of pleiotrophin in brain injuries: a narrative review of the literature

BACKGROUND

Pleiotrophin (PTN), a secreted multifunctional growth factor, is highly expressed in the developing brain. Recently, many studies have indicated that PTN participates in the development of brain and plays a neuroprotection after brain injury, especially promoting neuronal survival and neurite outgrowth, stimulating oligodendrocyte maturation and myelination, modulating neuroinflammation, and so on.

OBJECTIVE

However, no reviews comprehensively summarize the roles of PTN in brain injuries. Considering this, this review focuses on the roles and related regulatory pathways of PTN in brain injuries, what is known to date.

METHODS

PubMed and Embase databases have been searched, and related studies are compiled and summarized.

RESULTS

Our review has found PTN participates in the repairment of brain injuries, including hypoxic-ischemic brain injury, preterm white matter injury, traumatic brain injury, and neurodegenerative diseases, mainly based on animal data and small sample size studies. Besides, PTN interacts with receptors, such as, Z-type protein tyrosine phosphatase receptor and syndecan-3, regulating related pathways in these events.

CONCLUSION

It suggests PTN as a promising candidate for the treatment of brain injuries clinically. However, the evidence is early in its development. Further multi-center and large-sample studies are warranted to support our findings and determine the clinical value of PTN for treating brain injuries.

Using genomic structural equation modeling to examine the genetic architecture of PTSD and life satisfaction phenotypes

Objective: Posttraumatic stress disorder (PTSD) and life satisfaction phenotypes are inversely related on a phenotypic level. Given these established relations, researchers have begun to examine possible shared genetic contributions to these outcomes, though the existing genetic literature is sparse and examines these relations via univariate methods. We sought to examine the genetic architecture of PTSD and six life satisfaction and well-being phenotypes (i.e. subjective well-being, friend satisfaction, life satisfaction, family satisfaction, work satisfaction, and financial satisfaction) using a multivariate approach.Method: We used Genomic Structural Equation Modeling (gSEM) to analyze summary-level genetic data from large-scale GWAS of the European Ancestry.Results: Findings show that a two, correlated factors model fit the data best, in which PTSD and life satisfaction phenotypes load on separate but correlated factors.Conclusions: Findings suggest that, using multivariate methods, a latent factor capturing many different positive phenotypes is genetically related to PTSD. This finding confirms and extends prior phenotypic work demonstrating that PTSD and positive phenotypes are inversely related.

Maternal-infant probiotic transmission mitigates early-life stress-induced autism in mice

Autism, a disorder influenced by both genetic and environmental factors, presents significant challenges for prevention and treatment. While maternal-infant gut microbiota has been a focus in autism research, preventive strategies targeting maternal gut microbiota remain underexplored. This study demonstrates that prenatal probiotic intake can effectively prevent maternal separation-induced autistic-like behaviors in offspring without altering the embryonic neurodevelopment in mice. Using specific PCR primers and cross-fostering experiments, we traced the vertical transmission of probiotics, primarily via fecal/vaginal contamination. Early probiotic colonization conferred resilience against stress-induced gut pathogenic microbes and Th17-mediated peripheral inflammation while significantly inhibiting hypermyelination and neuroinflammation linked to systemic inflammation. Microbial metabolites like tyrosol and xanthurenic acid alleviated neuroinflammation and hypermyelination in vitro, though the causal relationship among neuroinflammation, hypermyelination, and autism in vivo requires further validation. These findings underscore the importance of the maternal-infant microbiota transmission window in autism prevention and highlight the clinical potential of prenatal probiotic interventions.

Regulation of dentate gyrus pattern separation by hilus ectopic granule cells

The dentate gyrus (DG) in hippocampus is reported to perform pattern separation, converting similar inputs into different outputs and thus avoiding memory interference. Previous studies have found that human and mice with epilepsy have significant pattern separation defects and a portion of adult-born granule cells (abGCs) migrate abnormally into the hilus, forming hilus ectopic granule cells (HEGCs). For the lack of relevant pathophysiological experiments, how HEGCs affect pattern separation remains unclear. Therefore, in this paper, we will construct the DG neuronal circuit and focus on discussing effects of HEGCs on pattern separation numerically. The obtained results showed that HEGCs impaired pattern separation efficiency since the sparse firing of granule cells (GCs) was destroyed. We provided new insights into the underlining mechanisms of HEGCs impairing pattern separation through analyzing two excitatory circuits: GC-HEGC-GC and GC-Mossy cell (MC)-GC, both of which involve the participation of HEGCs within the DG. It is revealed that the recurrent excitatory circuit GC-HEGC-GC formed by HEGCs mossy fiber sprouting significantly enhanced GCs activity, consequently disrupted pattern separation. However, another excitatory circuit had negligible effects on pattern separation due to the direct and indirect influences of MCs on GCs, which in turn led to the GCs sparse firing. Thus, HEGCs impair DG pattern separation mainly through the GC-HEGC-GC circuit and therefore ablating HEGCs may be one of the effective ways to improve pattern separation in patients with epilepsy.

IGHG4: innovative diagnostic biomarkers for iron overload in β-thalassemia patients

OBJECTIVES

This study aims to investigate the serotransferrin (TF), complement C1s subcomponent (C1S), immunoglobulin heavy constant gamma 4 (IGHG4), hemoglobin subunit alpha (HBA1), and clusterin (CLU) contents in β-thalassemia patients, and explores their physiological role as potential non-invasive bioindicators for disease diagnosis and iron overload.

METHODS

A total of 62 children with β-thalassemia were recruited and categorized by genotype, along with 17 healthy pediatric volunteers for analysis. The circulating ferritin content was evaluated, and plasma levels of TF, C1S, IGHG4, HBA1, and CLU were assessed using ELISA. The primary outcome of this study was the correlation between the five protein marker levels and iron overload. Continuous variables were analyzed using the Student's t-test or the Mann-Whitney U test. A binary logistic regression model identified independent predictors of iron overload in patients with β-thalassemia. Receiver operating characteristics (ROC) were employed to evaluate the model's performance.

RESULTS

The IGHG4 protein content was significantly lower in β-thalassemia patients compared to healthy controls. The IGHG4 protein content was reduced in the β+/β0 and β0/β0 patient populations compared to controls, with no significant difference observed between the β+/β0 group and healthy controls. A strong inverse relationship was identified between the IGHG4 protein content and SF concentration (r = -0.322, p = 0.004). Finally, plasma IGHG4 levels demonstrated adequate diagnostic capability, as indicated by our ROC curve analysis.

CONCLUSION

In conclusion, decreased IGHG4 protein levels are significantly associated with the degree of iron overload in β-thalassemia patients and may serve as a possible biomarker for evaluating iron overload.

Role of the C-terminal domain in modifying pH-dependent regulation of Cav1.4 Ca2+ channels

In the retina, Ca2+ influx through Cav1.4 Ca2+ channels triggers neurotransmitter release from rod and cone photoreceptors. Changes in extracellular pH modify channel opening, enabling a feedback regulation of photoreceptor output that contributes to the encoding of color and contrast. However, the mechanisms underlying pH-dependent modulation of Cav1.4 are poorly understood. Here, we investigated the role of the C-terminal domain (CTD) of Cav1.4 in pH-dependent modulation of Ba2+ currents (IBa) in HEK293T cells transfected with the full length CaV1.4 (FL) or variants lacking portions of the CTD due to alternative splicing (Δe47) or a disease-causing mutation (K1591X). While extracellular alkalinization caused an increase in IBa for each variant, the magnitude of this increase was significantly diminished (~40-50%) for both CTD variants; K1591X was unique in showing no pH-dependent increase in maximal conductance. Moreover, the auxiliary α2δ-4 subunit augmented the pH sensitivity of IBa, as compared to α2δ-1 or no α2δ, for FL and K1591X but not Δe47. We conclude that the CTD and α2δ-4 are critical determinants of pH-dependent modulation of Cav1.4 and may influence the processing of visual information in normal and diseased states of the retina.

Neural dynamics of deception: insights from fMRI studies of brain states

Deception is a complex behavior that requires greater cognitive effort than truth-telling, with brain states dynamically adapting to external stimuli and cognitive demands. Investigating these brain states provides valuable insights into the brain's temporal and spatial dynamics. In this study, we designed an experiment paradigm to efficiently simulate lying and constructed a temporal network of brain states. We applied the Louvain community clustering algorithm to identify characteristic brain states associated with lie-telling, inverse-telling, and truth-telling. Our analysis revealed six representative brain states with unique spatial characteristics. Notably, two distinct states-termed truth-preferred and lie-preferred-exhibited significant differences in fractional occupancy and average dwelling time. The truth-preferred state showed higher occupancy and dwelling time during truth-telling, while the lie-preferred state demonstrated these characteristics during lie-telling. Using the average z-score BOLD signals of these two states, we applied generalized linear models with elastic net regularization, achieving a classification accuracy of 88.46%, with a sensitivity of 92.31% and a specificity of 84.62% in distinguishing deception from truth-telling. These findings revealed representative brain states for lie-telling, inverse-telling, and truth-telling, highlighting two states specifically associated with truthful and deceptive behaviors. The spatial characteristics and dynamic attributes of these brain states indicate their potential as biomarkers of cognitive engagement in deception.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-025-10222-4.

DNA methylation markers of insulin resistance surrogate measures in the Atherosclerosis Risk in Communities (ARIC) study

Insulin resistance (IR) is a risk factor for cardiovascular diseases and type 2 diabetes. Associations between DNA methylation (DNAm) and IR have been less studied in African ancestry (AA) populations than those of European ancestry (EA). We aimed to identify associations between whole blood DNAm and IR in up to 1,811 AA and 964 EA participants from the Atherosclerosis Risk in Communities (ARIC) study. We quantified IR using three surrogate measures: the homeostasis model assessment of insulin resistance (HOMA-IR), the triglyceride-glucose index (TyG), and the triglyceride glucose-body mass index (TyG-BMI). We used ancestry-stratified linear regression models to conduct epigenome-wide association studies of IR, adjusting for batch effects and relevant covariates. Among 484,436 tested CpG sites, 39 were significantly associated with IR, of which 31% (10 in AA and two in EA) were associated with TyG-BMI and not previously reported for IR or related traits. These include a positive association at cg18335991-SEMA7A in AA. SEMA7A inhibits adipogenesis of preadipocytes and lipogenesis of mature adipocytes. DNAm levels at cg18335991 have been reported to be negatively associated with SEMA7A expression in blood. After additionally adjusting for smoking and drinking status, 15 of the 39 significant CpG sites remained significant or suggestive. Our study identified novel IR-associated CpG sites, contributing to a broader understanding of the epigenetic mechanisms underlying IR in diverse populations.

Visual image reconstructed without semantics from human brain activity using linear image decoders and nonlinear noise suppression

In recent years, substantial strides have been made in the field of visual image reconstruction, particularly in its capacity to generate high-quality visual representations from human brain activity while considering semantic information. This advancement not only enables the recreation of visual content but also provides valuable insights into the intricate processes occurring within high-order functional brain regions, contributing to a deeper understanding of brain function. However, considering fusion semantics in reconstructing visual images from brain activity involves semantic-to-image guide reconstruction and may ignore underlying neural computational mechanisms, which does not represent true reconstruction from brain activity. In response to this limitation, our study introduces a novel approach that combines linear mapping with nonlinear noise suppression to reconstruct visual images perceived by subjects based on their brain activity patterns. The primary challenge associated with linear mapping lies in its susceptibility to noise interference. To address this issue, we leverage a flexible denoised deep convolutional neural network, which can suppress noise from linear mapping. Our investigation encompasses linear mapping as well as the training of shallow and deep autoencoder denoised neural networks, including a pre-trained, state-of-the-art denoised neural network. The outcome of our study reveals that combining linear image decoding with nonlinear noise reduction significantly enhances the quality of reconstructed images from human brain activity. This suggests that our methodology holds promise for decoding intricate perceptual experiences directly from brain activity patterns without semantic information. Moreover, the model has strong neural explanatory power because it shares structural and functional similarities with the visual brain.

Mechanisms underlying EEG power changes during wakefulness in insomnia patients: a model-driven study

Insomnia, as a common sleep disorder, is the most common complaints in medical practice affecting a large proportion of the population on a situational, recurrent or chronic basis. It has been demonstrated that, during wakefulness, patients with insomnia exhibit increased EEG power in theta, beta, and gamma band. However, the relevant mechanisms underlying such power changes are still lack of understanding. In this paper, by combining the neural computational model with the real EEG data, we focus on exploring what's behind the EEG power changes for insomniac. We first develop a modified Liley model, named FSR-Liley, by respectively considering the fast and slow synaptic responses in inhibitory neurons along with the one-way projection between them. Then we introduce a parameter selection and evaluation method based on Markov chain Monte Carlo algorithm and Wasserstein distance, by which the sensitive parameters are selected automatically, and meanwhile, the optimal values of selected parameters are evaluated. Finally, through combining with EEG data, we determine the sensitive parameters in FSR-Liley and accordingly provide the mechanistic hypotheses: (1) decrease in P e i f , corresponding to the input from the thalamus to cortical inhibitory population with fast synaptic response, leads to the increased theta and beta power; (2) decrease in N e i f , corresponding to the projection from cortical excitatory population to inhibitory population with fast synaptic response, causes the increased gamma power. The results in this paper provide insights into the mechanisms of EEG power changes in insomnia and establish a theoretical foundation to support further experimental research.

EIciRNAs in focus: current understanding and future perspectives

Circular RNAs (circRNAs) are a unique class of covalently closed single-stranded RNA molecules that play diverse roles in normal physiology and pathology. Among the major types of circRNA, exon-intron circRNA (EIciRNA) distinguishes itself by its sequence composition and nuclear localization. Recent RNA-seq technologies and computational methods have facilitated the detection and characterization of EIciRNAs, with features like circRNA intron retention (CIR) and tissue-specificity being characterized. EIciRNAs have been identified to exert their functions via mechanisms such as regulating gene transcription, and the physiological relevance of EIciRNAs has been reported. Within this review, we present a summary of the current understanding of EIciRNAs, delving into their identification and molecular functions. Additionally, we emphasize factors regulating EIciRNA biogenesis and the physiological roles of EIciRNAs based on recent research. We also discuss the future challenges in EIciRNA exploration, underscoring the potential for novel functions and functional mechanisms of EIciRNAs for further investigation.

Exploring the potential for gene therapy in Cav1.4-related retinal channelopathies

The visual process begins with photon detection in photoreceptor outer segments within the retina, which processes light signals before transmission to the thalamus and visual cortex. Cav1.4 L-type calcium channels play a crucial role in this process, and dysfunction of these channels due to pathogenic variants in corresponding genes leads to specific manifestations in visual impairments. This review explores the journey from basic research on Cav1.4 L-type calcium channel complexes in retinal physiology and pathophysiology to their potential as gene therapy targets. Moreover, we provide a concise overview of key findings from studies using different animal models to investigate retinal diseases. It will critically examine the constraints these models present when attempting to elucidate retinal channelopathies. Additionally, the paper will explore potential strategies for addressing Cav1.4 channel dysfunction and discuss the current challenges facing gene therapy approaches in this area of research.

Correlation of extracellular vesicle Alu RNA with brain aging and neuronal injury: a potential biomarker for brain aging

BACKGROUND

Extracellular vesicles (EVs) are promising biomarkers for neurodegeneration. Alu elements are retrotransposons increasingly expressed with age and may be involved in aging-related diseases.

OBJECTIVE

To determine the potential of Alu RNA in plasma-derived EVs as a biomarker for brain aging and neuronal injury.

METHODS

EVs were isolated from plasma samples across different age groups. EV Alu RNA levels were measured and their associations with biomarkers of brain aging, including plasma neurofilament light chain (NfL), plasma amyloid-beta (Aβ42 and Aβ40), and plasma phosphorylated tau (p-Tau181), were analyzed.

RESULTS

EV Alu RNA levels were increased significantly with age and were strongly correlated with plasma NfL, suggesting a strong association between EV Alu RNA and neuronal injury. Significant correlations were also found between EV Alu RNA and plasma amyloid-beta levels, while no significant association was observed with tau pathology.

CONCLUSIONS

EV Alu RNA levels are elevated with age and associated with neuronal injury, highlighting their potential as a novel, non-invasive biomarker for brain aging and neurodegeneration.

Gut-brain axis and environmental factors in Parkinson's disease: bidirectional link between disease onset and progression

Parkinson's disease has long been considered a disorder that primarily affects the brain, as it is defined by the dopaminergic neurodegeneration in the substantia nigra and the brain accumulation of Lewy bodies containing α-synuclein protein. In recent decades, however, accumulating research has revealed that Parkinson's disease also involves the gut and uncovered an intimate and important bidirectional link between the brain and the gut, called the "gut-brain axis." Numerous clinical studies demonstrate that gut dysfunction frequently precedes motor symptoms in Parkinson's disease patients, with findings including impaired intestinal permeability, heightened inflammation, and distinct gut microbiome profiles and metabolites. Furthermore, α-synuclein deposition has been consistently observed in the gut of Parkinson's disease patients, suggesting a potential role in disease initiation. Importantly, individuals with vagotomy have a reduced Parkinson's disease risk. From these observations, researchers have hypothesized that α-synuclein accumulation may initiate in the gut and subsequently propagate to the central dopaminergic neurons through the gut-brain axis, leading to Parkinson's disease. This review comprehensively examines the gut's involvement in Parkinson's disease, focusing on the concept of a gut-origin for the disease. We also examine the interplay between altered gut-related factors and the accumulation of pathological α-synuclein in the gut of Parkinson's disease patients. Given the accessibility of the gut to both dietary and pharmacological interventions, targeting gut-localized α-synuclein represents a promising avenue for developing effective Parkinson's disease therapies.