Functional recovery following spinal cord injury will require the regeneration and repair of damaged neuronal pathways. It is well known that the tissue response to injury involves inflammation and the formation of a glial scar at the lesion site, which significantly impairs the capacity for neuronal regeneration and functional recovery. There are initial attempts by both supraspinal and intraspinal neurons to regenerate damaged axons, often influenced by the neighboring tissue pathology. Many experimental therapeutic strategies are targeted to further stimulate the initial axonal regrowth, with little consideration for the diversity of the affected neuronal populations. Notably, recent studies reveal that the neuronal response to injury is variable, based on multiple factors, including the location of the injury with respect to the neuronal cell bodies and the affected neuronal populations. New insights into regenerative mechanisms have shown that neurons are not homogenous but instead exhibit a wide array of diversity in their gene expression, physiology, and intrinsic responses to injury. Understanding this diverse intrinsic response is crucial, as complete functional recovery requires the successful coordinated regeneration and reorganization of various neuron pathways. Neurons in the brain and spinal cord are a diverse group of cells with many populations and subtypes. To facilitate recovery of function post-injury, understanding the unique individual responses of these neurons to injury is going to be critical.
Western diet-induced cognitive dysfunction is a rapidly emerging health challenge driven by excessive intake of high-fat, high-sugar, and ultra-processed foods. These dietary patterns promote neuroinflammation, oxidative stress, insulin resistance, gut dysbiosis, and blood-brain barrier (BBB) disruption, ultimately leading to synaptic dysfunction and cognitive decline. Crocetin, an apocarotenoid derived from saffron and Gardenia jasminoides, exhibits promising neuroprotective effects by scavenging reactive oxygen species, attenuating neuroinflammatory signaling, enhancing mitochondrial bioenergetics, and improving insulin sensitivity. It further upregulates brain-derived neurotrophic factor (BDNF), modulates PI3K/Akt signaling, and restores gut microbiota balance, thereby reinforcing the gut-brain axis and maintaining BBB integrity. This review further aims to critically assess these mechanistic links by distinguishing well-supported findings from speculative associations emphasizing discrepancies between preclinical and human evidence. Preclinical studies strongly support crocetin's role in ameliorating Western diet-induced neurodegeneration, while early clinical evidence highlights improvements in memory, executive function, and cerebral blood flow. However, limitations such as poor bioavailability, rapid metabolism, and limited large-scale human trials constrain its translation into clinical practice. Advanced formulations, including nanoparticles, liposomes, and prodrug derivatives, hold potential to overcome these challenges. This review critically evaluates the pathophysiological mechanisms of Western diet-induced cognitive decline, highlights the pharmacological actions of crocetin, and discusses its therapeutic prospects within the framework of personalized and precision medicine. Future directions include large-scale randomized controlled trials, pharmacokinetic optimization, and AI-driven predictive models to establish crocetin as a clinically viable neuroprotective agent.
Vitamin D is a secosteroid hormone with myriad physiological functions, including pleiotropic effects in the central nervous system. Vitamin D deficiency has been linked to multiple neurodevelopmental and neurodegenerative diseases, including Rett syndrome, epilepsy, Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Over the past decades, vitamin D supplementation has been used as a preventative measure or a therapeutic intervention, often with inconsistent or variable responses. We discuss the known association between vitamin D deficiency and neurological disorder occurrence or progression for these disorders. Further, we assess the underlying causes for disruptions in vitamin D levels and the potential mechanisms of vitamin D-mediated improvements. We discuss disruptions in the vitamin D metabolism pathway, signaling, and/or feedback homeostasis that could underpin individual responses to vitamin D supplementation in these disorders. We further discuss the intersection between the vitamin D and cholesterol synthesis pathways and neuroinflammation, and the complex interactions that could contribute to the broad impact of vitamin D on neurological disorders.
Ventromedial hypothalamic nucleus (VMN) growth hormone-releasing hormone (Ghrh) neurotransmission shapes counterregulatory hormone secretion. Dorsomedial VMN Ghrh neurons express the metabolic-sensitive transcription factor steroidogenic factor-1/NR5A1 (SF-1). In vivo SF-1 gene knockdown tools were used here to address the premise that in male rats, SF-1 may regulate basal and/or hypoglycemic patterns of Ghrh, co-transmitter biosynthetic enzyme, and estrogen receptor (ER) gene expression in these neurons. Single-cell multiplex qPCR analyses showed that SF-1 regulates basal profiles of mRNAs that encode Ghrh and protein markers for neurochemicals that suppress (γ-aminobutyric acid) or enhance (nitric oxide; glutamate) counterregulation. SF-1 siRNA pretreatment respectively exacerbated or blunted hypoglycemia-associated inhibition of glutamate decarboxylase67 (GAD67/GAD1) and -65 (GAD65/GAD2) transcripts. Hypoglycemia augmented or reduced nitric oxide synthase and glutaminase mRNAs, responses that were attenuated by SF-1 gene silencing. Ghrh and Ghrh receptor transcripts were correspondingly refractory to or increased by hypoglycemia, yet SF-1 knockdown decreased both gene profiles. Hypoglycemic inhibition of ER-alpha and G protein-coupled-ER gene expression was amplified by SF-1 siRNA pretreatment, whereas as ER-beta mRNA was amplified. SF-1 knockdown decreased (corticosterone) or elevated [glucagon, growth hormone (GH)] basal counterregulatory hormone profiles, but amplified hypoglycemic hypercorticosteronemia and -glucagonemia or prevented elevated GH release. Outcomes document SF-1 control of VMN Ghrh neuron counterregulatory neurotransmitter and ER gene transcription. SF-1 likely regulates Ghrh nerve cell receptivity to estradiol and release of distinctive neurochemicals during glucose homeostasis and systemic imbalance. VMN Ghrh neurons emerge as a likely substrate for SF-1 control of glucose counterregulation in the male rat.
The prospect that the ventromedial hypothalamic nucleus (VMN) transcription factor steroidogenic factor-1/NR5A1 (SF-1) may exert sex-dimorphic control of glucose counterregulation is unresolved. Recent studies in male rats show that SF-1 regulates transcription of co-expressed hypoglycemia-sensitive neurochemicals in dorsomedial VMN growth hormone-releasing hormone (Ghrh) neurons. Gene knockdown and laser-catapult-microdissection/single-cell multiplex qPCR techniques were used here in a female rat model to determine if SF-1 control of Ghrh neuron transmitter marker, energy sensor, and estrogen receptor (ER) variant mRNAs varies according to sex. Data show that in females, hypoglycemia elicits a gain of SF-1 inhibitory control of VMNdm Ghrh neuron Ghrh and Ghrh-receptor gene profiles and loss of augmentation of glutaminase transcription; SF-1 gene silencing diminished eu- and hypoglycemic patterns of neuronal nitric oxide gene transcription. SF-1 imposes divergent control of baseline and hypoglycemic glutamate decarboxylase65 (GAD)-1 (stimulatory) versus GAD2 (inhibitory) mRNAs in that sex. SF-1 stimulates baseline VMNdm Ghrh neuron PRKAA1/AMPKα1 and PRKAA2/AMPKα2 gene expression, yet causes opposite changes in these gene profiles during hypoglycemia. SF-1 exerts glucose-dependent control of ER-alpha and G-protein-coupled ER-1 transcription, but blunts ER-beta gene profiles during eu- and hypoglycemia. In females, SF-1 knockdown did not affect hypercorticosteronemia or hyperglucagonemia, but blunted hypoglycemic suppression of growth hormone secretion. Results show that SF-1 expression is critical for female rat VMNdm Ghrh neuron counterregulatory neurochemical, AMPK catalytic subunit, and ER gene transcription responses to hypoglycemia. Sex differences in direction of SF-1 control of distinctive gene profiles may result in observed disparities in SF-1 regulation of counterregulatory hormone secretion between sexes.
Neurogenesis in the dentate gyrus of the hippocampus is a conserved and highly regulated process throughout the lifespan. Hippocampal neural stem and progenitor cells (NSPCs) can either transition into an activated proliferative state or remain quiescent. Accumulating data suggests that mitochondrial fatty acid β-oxidation is important in maintaining NSPCs quiescence under normal physiological conditions; however, the contribution of this pathway in NSPCs following brain injury remains unknown. While severe traumatic brain injury (TBI) is characterized by increased NSPCs proliferation in the hippocampus, the extent of this proliferative response after mild TBI, the most prevalent form of TBI, has not been fully delineated. Using closed head injury as a model of mild TBI and a brain-specific knockout mouse of carnitine palmitoyltransferase 2 (CPT2; an obligate gene in mitochondrial fatty acid β-oxidation), we investigated the role of fatty acid oxidation in hippocampal NSPCs proliferation in naïve and injured male and female mice. Our results show that loss of CPT2 in the brain does not affect hippocampal proliferation in naïve mice. Furthermore, mild TBI upregulates proliferation at day 3 post-injury, and is further increased only in male CPT2-deficient mice. Despite the post-injury increase in hippocampal NSPCs proliferation in CPT2B-/- mice, long-term neurogenesis remained unchanged. Together, these data provides a new insight into the metabolic regulation of NSPCs neurogenesis in the hippocampus following mild traumatic brain injury.
Long-term effects of alcohol-related brain damage (ARBD) include neurocognitive and neurobehavioral dysfunctions with neurodegeneration. White matter (WM) is notably targeted across the lifespan yet relatively little is known about the stages, mechanisms, and consequences of myelin and axonal loss. In alcohol-related liver disease, early pathology is reversible, but with chronic heavy alcohol exposures, disease progresses with degeneration, and ultimately organ failure. Similarly, WM ARBD also develops in two broad stages. The early stages of WM ARBD are likely mediated by vascular dysfunction with tissue swelling, oligodendrocyte dysfunction, myelin loss, neuroinflammation, and oxidative stress. The chronic progressive stage is linked to metabolic dysfunction related to impairments in insulin and insulin-like growth factor signaling through Akt-mechanistic target of rapamycin (mTOR) pathways that mediate oligodendrocyte survival and function, myelin homeostasis, and blood-brain-barrier (BBB) integrity. We hypothesize that early-stage WM ARBD may be largely reversible by abstinence and anti-oxidant/anti-inflammatory measures, whereas late-stage ARBD requires strategies to restore WM/oligodendrocyte metabolic function via insulin sensitizer, antioxidant, anti-inflammatory, and myelin homeostasis/normalization support. Multi-pronged, overlapping but distinct therapeutic strategies are needed to reduce the impact and long-term health consequences of chronic progressive WM ARBD.
Activation of the innate immune system following pattern recognition receptor binding has emerged as one of the major pathogenic mechanisms in neurodegenerative disease. Experimental, epidemiological, pathological, and genetic evidence underscores the meaning of innate immune activation during the prodromal as well as clinical phases of several neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and frontotemporal dementia. Importantly, innate immune activation and the subsequent release of inflammatory mediators contribute mechanistically to other hallmarks of neurodegenerative diseases such as aberrant proteostatis, pathological protein aggregation, cytoskeleton abnormalities, altered energy homeostasis, RNA and DNA defects, and synaptic and network disbalance and ultimately to the induction of neuronal cell death. In this review, we discuss common mechanisms of innate immune activation in neurodegeneration, with particular emphasis on the pattern recognition receptors (PRRs) and other receptors involved in the detection of damage-associated molecular patterns (DAMPs).
The loss of brain noradrenergic neurons is one of the earliest alterations observed in Alzheimer's disease and other neurodegenerative pathologies. The consequent reduction of brain noradrenaline levels facilitates the progression of neuroinflammatory processes that can be fatal for neurons and other brain cells. For this reason, compensating for noradrenaline deficit through different means constitutes an interesting therapeutic strategy. Drugs that inhibit the reuptake of noradrenaline are used to elevate the extracellular concentrations of this neurotransmitter and potentiate this way its effects. These drugs are approved for the treatment of depression or attention deficit hyperactivity disorder, among other indications, but their repurposing and use in Alzheimer's disease could be of interest given the beneficial effects observed for noradrenaline in numerous studies. Based on this, we previously showed the beneficial effects of reboxetine, a noradrenaline reuptake inhibitor, on 5xFAD mice that accumulate amyloid beta in their brains and reproduce some of the typical alterations of Alzheimer's disease. In this study we have analyzed the effects of reboxetine on P301S mice, a different model of Alzheimer's disease based on the expression of mutant forms of human microtubule-associated protein tau. We observed that the administration of reboxetine with osmotic pumps for 28 days to 9-month-old mice reduced the accumulation and activation of microglia and astrocytes in different areas of the hippocampus. These findings indicate that reboxetine treatment prevents the neuroinflammatory response known to cause brain damage in Alzheimer's disease even when the treatment is initiated at an advanced stage of the disease.
Omega-3 polyunsaturated fatty acids (ω3 PUFAs) are critical structural components of neuronal membranes, yet the molecular specificity of their incorporation within neural cells remains incompletely defined. We integrated untargeted and targeted lipidomics with lipid ontology analysis and coarse-grained membrane simulations to characterize remodeling in primary rat cortical neurons and neuron-astrocyte co-cultures following supplementation with docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), or docosapentaenoic acid (DPA). Each ω3 PUFA produced a distinct lipidomic signature. DHA showed the most consistent incorporation, selectively enriching phosphatidylethanolamine (PE) species-particularly PE(18:0/22:6) and PE(18:1/22:6)-associated with membrane curvature and organelle organization. Ontology analysis linked DHA supplementation to intrinsic curvature-related membrane features, and membrane simulations demonstrated enhanced collective bilayer bending without substantial changes in overall membrane thickness. EPA preferentially increased EPA-containing PE species without elevating DHA levels, whereas DPA effects were variable and culture-dependent, indicating selective metabolic handling of individual ω3 species. Differences between neurons and neuron-astrocyte co-cultures underscore the importance of cellular context in ω3-driven remodeling. By resolving ω3 incorporation at molecular species resolution and linking compositional changes to predicted membrane behavior, this study provides a structural framework for understanding how dietary ω3 fatty acids may influence neuronal membrane organization and cellular resilience.
Our study examines brain metabolic connectivity in SARS-CoV-2 survivors during the acute-subacute and chronic phases, aiming to elucidate the mechanisms underlying the persistence of neurological symptoms in long-COVID patients. We perfomed a cross-sectional study including 44 patients (pts) with neurological symptoms who underwent FDG-PET scans, and classified to timing infection as follows: acute (7 pts), subacute (17 pts), long-term (20 pts) phases. Interregional correlation analysis (IRCA) and ROI-based IRCA were applied on FDG-PET data to extract metabolic connectivity in resting state networks (ADMN, PDMN, EXN, ATTN, LIN, ASN) of neuro-COVID pts in acute/subacute and long-term groups compared with healthy controls (HCs). Univariate approach was used to investigate metabolic alterations from the acute to sub-acute and long-term phase. The acute/subacute phase was characterized by hyperconnectivity in EXN and ATTN networks; the same networks showed hypoconnectivity in the chronic phase. EXN and ATTN hypoconnectivity was consistent with clinical findings in long-COVID patients, e.g. altered performances in neuropsychological tests of executive and attention domains. The ASN and LIN presented hyperconnectivity in acute/subacute phase and normalized in long-term phase. The ADMN and PDMN presented a preseverved connectivity. Univariate analysis showed hypometabolism in fronto-insular cortex in acute phase, which reduced in sub-acute phase and disappeared in long-term phase. A compensatory EXN and ATTN hyperconnectivity was found in the acute/subacute phase and hypoconnectivity in long-term. Hypoconnectivity and absence of hypometabolism suggest that connectivity derangement in frontal networks could be related to protraction of neurological symptoms in long-term COVID patients.
Promising new pharmacological strategies for the enhancement of cognition target either nicotinic acetylcholine receptors (nAChR) or N-methyl-D-aspartate receptors (NMDAR). There is also an increasing interest in low-dose combination therapies co-targeting the above neurotransmitter systems to reach greater efficacy over the monotreatments and to reduce possible side effects of high-dose monotreatments. In the present study, we assessed modulatory effects of the α7 nAChR-selective agonist PHA-543613 (PHA), a novel α7 nAChR positive allosteric modulator compound (CompoundX) and the NMDAR antagonist memantine on the in vivo firing activity of CA1 pyramidal neurons in the rat hippocampus. Three different test conditions were applied: spontaneous firing activity, NMDA-evoked firing activity and ACh-evoked firing activity. Results showed that high but not low doses of memantine decreased NMDA-evoked firing activity, and low doses increased the spontaneous and ACh-evoked firing activity. Systemically applied PHA robustly potentiated ACh-evoked firing activity with having no effect on NMDA-evoked activity. In addition, CompoundX increased both NMDA- and ACh-evoked firing activity, having no effects on spontaneous firing of the neurons. A combination of low doses of memantine and PHA increased firing activity in all test conditions and similar effects were observed with memantine and CompoundX but without spontaneous firing activity increasing effects. Our present results demonstrate that α7 nAChR agents beneficially interact with Alzheimer's disease medication memantine. Moreover, positive allosteric modulators potentiate memantine effects on the right time and the right place without affecting spontaneous firing activity. All these data confirm previous behavioral evidence for the viability of combination therapies for cognitive enhancement.
Elevated levels of Chitinase-3-like protein-1 (CHI3L1) in cerebrospinal fluid have previously been linked to inflammatory activity and disease progression in multiple sclerosis (MS) patients. This study aimed to investigate the presence of CHI3L1 in the brains of MS patients and in the cuprizone model in mice (CPZ), a model of toxic/metabolic demyelination and remyelination in different brain areas. In MS gray matter (GM), CHI3L1 was detected primarily in astrocytes and in a subset of pyramidal neurons. In neurons, CHI3L1 immunopositivity was associated with lipofuscin-like substance accumulation, a sign of cellular aging that can lead to cell death. The density of CHI3L1-positive neurons was found to be significantly higher in normal-appearing MS GM tissue compared to that of control subjects (p  =  .014). In MS white matter (WM), CHI3L1 was detected in astrocytes located within lesion areas, as well as in perivascular normal-appearing areas and in phagocytic cells from the initial phases of lesion development. In the CPZ model, the density of CHI3L1-positive cells was strongly associated with microglial activation in the WM and choroid plexus inflammation. Compared to controls, CHI3L1 immunopositivity in WM was increased from an early phase of CPZ exposure. In the GM, CHI3L1 immunopositivity increased later in the CPZ exposure phase, particularly in the deep GM region. These results indicate that CHI3L1 is associated with neuronal deterioration, pre-lesion pathology, along with inflammation in MS.
Cerebral ischemia is defined by insufficient blood supply to the brain and is a leading cause of mortality and neurological disability worldwide. Alpha-synuclein (α-Syn) is a protein associated with several neurodegenerative disorders, including Parkinson's disease, and has also been linked to the pathophysiology of cerebral ischemia. This narrative review provides a detailed overview of the current understanding of α-Syn in cerebral ischemia. We examine its impact on neuroinflammation, synaptic dysfunction, oxidative stress, and neuronal cell death, as well as its potential protective roles. Additionally, we explore therapeutic strategies targeting α-Syn, including pharmacological agents, gene knockdown models, and RNA-based therapies. We also discuss α-Syn expression changes in animal and human studies and its potential as a diagnostic biomarker. By clarifying the complex interplay between α-Syn and cerebral ischemia, this review aims to deepen our understanding of ischemic brain injury mechanisms and support the development of novel treatment approaches.
Pharmacological stimulation/antagonism of astrocyte glio-peptide octadecaneuropeptide signaling alters ventromedial hypothalamic nucleus (VMN) counterregulatory γ-aminobutyric acid (GABA) and nitric oxide transmission. The current research used newly developed capillary zone electrophoresis-mass spectrometry methods to investigate hypoglycemia effects on VMN octadecaneuropeptide content, along with gene knockdown tools to determine if octadecaneuropeptide signaling regulates these transmitters during eu- and/or hypoglycemia. Hypoglycemia caused dissimilar adjustments in the octadecaneuropeptide precursor, i.e., diazepam-binding-inhibitor and octadecaneuropeptide levels in dorsomedial versus ventrolateral VMN. Intra-VMN diazepam-binding-inhibitor siRNA administration decreased baseline 67 and 65 kDa glutamate decarboxylase mRNA levels in GABAergic neurons laser-microdissected from each location, but only affected hypoglycemic transcript expression in ventrolateral VMN. This knockdown therapy imposed dissimilar effects on eu- and hypoglycemic glucokinase and 5'-AMP-activated protein kinase-alpha1 (AMPKα1) and -alpha2 (AMPKα2) gene profiles in dorsomedial versus ventrolateral GABAergic neurons. Diazepam-binding-inhibitor gene silencing up-regulated baseline (dorsomedial) or hypoglycemic (ventrolateral) nitrergic neuron neuronal nitric oxide synthase mRNA profiles. Baseline nitrergic cell glucokinase mRNA was up- (ventrolateral) or down- (dorsomedial) regulated by diazepam-binding-inhibitor siRNA, but knockdown enhanced hypoglycemic profiles in both sites. Nitrergic nerve cell AMPKα1 and -α2 transcripts exhibited division-specific responses to this genetic manipulation during eu- and hypoglycemia. Results document the utility of capillary zone electrophoresis-mass spectrometric tools for quantification of ODN in small-volume brain tissue samples. Data show that hypoglycemia has dissimilar effects on ODN signaling in the two major neuroanatomical divisions of the VMN and that this glio-peptide imposes differential control of glucose-regulatory neurotransmission in the VMNdm versus VMNvl during eu- and hypoglycemia.
This study demonstrates that electroacupuncture (EA) produces robust antidepressant effects in a rat model of methamphetamine (METH) withdrawal. Behavioral tests showed that EA applied at GV20, PC6, and HT7 significantly reduced immobility in the forced swim test and enhanced exploratory activity in the open field test. Mechanistically, EA repaired blood-brain barrier (BBB) disruption, as shown by reduced hippocampal water content, decreased Evans Blue leakage, and restored expression of tight-junction proteins (Occludin, Claudin-5, ZO-1). EA also inhibited neuronal apoptosis, suppressed microglial activation, and lowered pro-inflammatory cytokines IL-6 and TNF-α. Multi-omics analyses revealed that EA reversed METH-induced alterations in 32 differentially expressed genes related to the NLRP3 inflammasome pathway (Nlrp3, Pycard, Il1b) and BBB function, while metabolomic profiling identified 13 key metabolites involved in glutamate metabolism, TCA cycle, and tryptophan pathways. Crucially, the therapeutic benefits of EA were abolished by intracerebroventricular administration of the NLRP3 activator nigericin, confirming the essential role of NLRP3 inflammasome inhibition in EA's mechanism of action. In summary, EA represents a promising non-pharmacological approach for treating METH withdrawal-induced depression by coordinating BBB protection, suppression of neuroinflammation, and metabolic network regulation. 1. This study first reports that electroacupuncture alleviates METH-withdrawal depression by targeting the NLRP3 inflammasome pathway.2. This study found that electroacupuncture significantly restores BBB integrity and reduces neuroinflammation in METH-withdrawn rats.3. This study identified key transcriptomic changes (e.g., Nlrp3, Il1b) and metabolic alterations (glutamate, TCA, tryptophan) reversed by electroacupuncture.4. This study demonstrated that the NLRP3 activator nigericin abolishes electroacupuncture’s therapeutic benefits, confirming pathway dependence.5. This study provides a new theoretical basis for non-pharmacological intervention in substance withdrawal-induced depression.
GABA receptors are classically known for driving neuronal hyperpolarization and modulating synaptic transmission. In glial cells, however, GABA induces depolarization and triggers calcium-dependent signaling pathways. Müller glia, the principal retinal glial population, maintain retinal homeostasis and are the major source of neuroretinal VEGF-A, a key angiogenic factor in development and disease. Although GABA receptor (GABAR) activity has been proposed to influence retinal VEGF-A, it remains unclear whether this regulation occurs through Müller glial cells (MGC) and which mechanisms are involved. Here, we investigated how GABAR activation modulates VEGF-A in primary mouse MGC cultures. Cells were exposed to GABA and selective agonists or antagonists of GABAA (muscimol, gabazine) and GABAB receptors (baclofen, CGP55845). VEGF-A expression and secretion were analyzed by immunofluorescence, western blot, RT-qPCR, and ELISA. To assess Ca2+ involvement, we used Ca2+-free Ringer-Krebs solution and the L-type channel blocker nimodipine, and examined MAPK signaling with the ERK1/2 inhibitor FR180204. Our findings show that GABA and muscimol increased VEGF-A fluorescence intensity after 48 hours while reducing VEGF-A secretion, without altering Vegfa mRNA. Both effects were abolished by extracellular Ca2+ removal or nimodipine, indicating a Ca2+-dependent mechanism. FR180204 also attenuated GABA- and GABAA-mediated effects, implicating MAPK signaling. Short-term assays revealed that GABA rapidly elevates VEGF-A protein and secretion within ∼30 minutes. Together, these findings identify a Ca2+- and GABAA-dependent pathway through which Müller glia regulate VEGF-A production and release, providing new insight into glial signaling and neurotransmitter-driven modulation of retinal angiogenic factors.
Repair after peripheral nerve injury (PNI) faces major obstacles due to microenvironmental imbalance and neuronal loss. Ferroptosis, an iron-dependent cell death driven by lipid peroxidation, has emerged as a key pathological event in PNI, linking oxidative stress, mitochondrial dysfunction, and inflammation to regenerative failure. Targeting ferroptosis protects vital cells-such as Schwann cells and neurons-and ameliorates the regenerative niche, offering a promising therapeutic strategy. This review elucidates the mechanisms of ferroptosis in PNI, detailing its roles in Schwann cells, dorsal root ganglion neurons, and macrophages via core pathways including Nrf2/HO-1/GPX4 and ACSL4. We further evaluate current intervention strategies and their therapeutic efficacy. This synthesis provides novel insights into PNI pathology and guides the development of innovative treatments.
Thy1, a synaptic protein, may support synaptic junction adherence. Thus, we hypothesized that loss of Thy1 may alter synaptic transmission. Our focus on the Thy1 knockout (KO) mouse model stems from the loss of Thy1 expression in individuals with Restless Legs Syndrome (RLS), a neurological disorder. This investigation aimed to determine: 1) if the absence of Thy1 affects synaptic function in the striatal region, 2) if the absence of Thy1 alters the synaptic response to dopamine and gabapentin, and 3) if the Thy1 loss can alter behavior modulated by the striatum. Network-level synaptic transmission was measured in corticostriatal slices from Thy1 KO and C57BL/6 control mice. In vivo, acoustic startle behavioral testing was used to measure startle reaction and prepulse inhibition in both groups. Raclopride, a D2 receptor antagonist, decreased population spike amplitude in control but not Thy1 KO slices. Quinpirole, a D2 receptor agonist, did not change spike amplitude in any group. Gabapentin, a Ca2+ channel blocker, reduced population spike amplitude in Thy1 KO slices more than in controls. The behavioral acoustic startle response was diminished in Thy1 KO mice and attributed to enhanced prepulse inhibition. Loss of Thy1 alters striatal synaptic function, affecting dopaminergic modulation of corticostriatal neurotransmission and resulting in disruption of the startle response and prepulse inhibition. Loss of Thy1 affects dopaminergic modulation of corticostriatal neurotransmission.Loss of Thy1 alters the pharmacological response to dopaminergic agents and gabapentin.Loss of Thy1 affects startle response to auditory stimuli.Thy1 knockout in mice affects neural mechanisms common to restless legs syndrome.
Hexanucleotide repeat expansion (HRE) in the non-coding region of the gene C9orf72 is the most prevalent mutation in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The C9orf72 HRE contributes to neuron degeneration in ALS/FTD through both cell-autonomous mechanisms and non-cell autonomous disease processes involving glial cells such as microglia. The molecular mechanisms underlying the contribution of C9orf72-HRE microglia to neuron death in ALS/FTD remain to be fully elucidated. In this study, we generated microglia from human C9orf72-HRE and isogenic iPSCs using three different microglia derivation methods. RNA sequencing analysis reveals a cell-autonomous dysregulation of extracellular matrix (ECM) genes and genes involved in pathways underlying inflammasome activation in C9orf72-HRE microglia. In agreement with elevated expression of inflammasome components, conditioned media from C9orf72-HRE microglia enhance the death of C9orf72-HRE motor neurons implicating microglia-secreted molecules in non-cell autonomous mechanisms of C9orf72 HRE pathology. These findings suggest that aberrant activation of inflammasome-mediated mechanisms in C9orf72-HRE microglia results in a pro-inflammatory phenotype that contributes to non-cell autonomous mechanisms of motor neuron degeneration in ALS/FTD.