Star power: harnessing the reactive astrocyte response to promote remyelination in multiple sclerosis

Astrocytes are indispensable for central nervous system development and homeostasis.In response to injury and disease,astrocytes are integral to the immunological-and the,albeit limited,repair response.In this review,we will examine some of the functions reactive astrocytes play in the context of multiple sclerosis and related animal models.We will consider the heterogeneity or plasticity of astrocytes and the mechanisms by which they promote or mitigate demyelination.Finally,we will discuss a set of biomedical strategies that can stimulate astrocytes in their promyelinating response.

EZH2-dependent myelination following sciatic nerve injury

Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury.Notably,the gene regulatory network of regenerated myelin differs from that of native myelin.Silencing of enhancer of zeste homolog 2(EZH2)hinders the differentiation,maturation,and myelination of Schwann cells in vitro.To further determine the role of EZH2 in myelination and recovery post-peripheral nerve injury,conditional knockout mice lacking Ezh2 in Schwann cells(Ezh2^(fl/fl);Dhh-Cre and Ezh2^(fl/fl);Mpz-Cre)were generated.Our results show that a significant proportion of axons in the sciatic nerve of Ezh2-depleted mice remain unmyelinated.This highlights the crucial role of Ezh2 in initiating Schwann cell myelination.Furthermore,we observed that 21 days after inducing a sciatic nerve crush injury in these mice,most axons had remyelinated at the injury site in the control nerve,while Ezh2^(fl/fl);Mpz-Cre mice had significantly fewer remyelinated axons compared with their wild-type littermates.This suggests that the absence of Ezh2 in Schwann cells impairs myelin formation and remyelination.In conclusion,EZH2 has emerged as a pivotal regulatory factor in the process of demyelination and myelin regeneration following peripheral nerve injury.Modulating EZH2 activity during these processes may offer a promising therapeutic target for the treatment of peripheral nerve injuries.

Overview of emerging therapies for demyelinating diseases

This paper provides an overview of autoimmune disorders of the central nervous system,specifically those caused by demyelination.We explore new research regarding potential therapeutic interventions,particularly those aimed at inducing remyelination.Remyelination is a detailed process,involving many cell types–oligodendrocyte precursor cells(OPCs),astrocytes,and microglia–and both the innate and adaptive immune systems.Our discussion of this process includes the differentiation potential of neural stem cells,the function of adult OPCs,and the impact of molecular mediators on myelin repair.Emerging therapies are also explored,with mechanisms of action including the induction of OPC differentiation,the transplantation of mesenchymal stem cells,and the use of molecular mediators.Further,we discuss current medical advancements in relation to many myelin-related disorders,including multiple sclerosis,optic neuritis,neuromyelitis optica spectrum disorder,myelin oligodendrocyte glycoprotein antibodyassociated disease,transverse myelitis,and acute disseminated encephalomyelitis.Beyond these emerging systemic therapies,we also introduce the dimethyl fumarate/silk fibroin nerve conduit and its potential role in the treatment of peripheral nerve injuries.Despite these aforementioned scientific advancements,this paper maintains the need for ongoing research to deepen our understanding of demyelinating diseases and advance therapeutic strategies that enhance affected patients’quality of life.

Demyelinating neuropathy in patients with hepatitis B virus: A case report

BACKGROUND Hepatitis B rarely leads to demyelinating neuropathy,despite peripheral neuropathy being the first symptom of hepatitis B infection.CASE SUMMARY A 64-year-old man presented with sensorimotor symptoms in multiple peripheral nerves.Serological testing showed that these symptoms were due to hepatitis B.After undergoing treatment involving intravenous immunoglobulin and an antiviral agent,there was a notable improvement in his symptoms.CONCLUSION Although hepatitis B virus(HBV)infection is known to affect hepatocytes,it is crucial to recognize the range of additional manifestations linked to this infection.The connection between long-term HBV infection and demyelinating neuropathy has seldom been documented;hence,prompt diagnostic and treatment are essential.The patient's positive reaction to immunoglobulin seems to be associated with production of the antigen-antibody immune complex.

An Investigation on the Application of Online and Offline Hybrid Teaching in Local Anatomy Course of Acupuncture and Moxibustion Specialty

The purpose of this paper is to explore the application of online and offline blended teaching in local anatomy courses of acupuncture specialty.It introduces the concept and characteristics of blended teaching mode and analyzes the respective advantages of online and offline teaching as well as the advantages and application prospects of blended teaching mode.The teaching status quo of local anatomy courses in acupuncture and moxibustion is analyzed,pointing out the problems of the traditional teaching mode and the application prospect of the blended teaching mode.In the practical part,the preparation and design of online teaching resources,the design of offline practical teaching sessions,and the evaluation methods of teaching effect are introduced in detail.This study aims to provide new teaching modes and ideas for teaching acupuncture and moxibustion and promote the improvement of teaching quality.

The circ_0002538/miR-138-5p/plasmolipin axis regulates Schwann cell migration and myelination in diabetic peripheral neuropathy

Circular RNAs(circRNAs)play a vital role in diabetic peripheral neuropathy.However,their expression and function in Schwann cells in individuals with diabetic peripheral neuropathy remain poorly understood.Here,we performed protein profiling and circRNA sequencing of sural nerves in patients with diabetic peripheral neuropathy and controls.Protein profiling revealed 265 differentially expressed proteins in the diabetic peripheral neuropathy group.Gene Ontology indicated that differentially expressed proteins were mainly enriched in myelination and mitochondrial oxidative phosphorylation.A real-time polymerase chain reaction assay performed to validate the circRNA sequencing results yielded 11 differentially expressed circRNAs.circ_0002538 was markedly downregulated in patients with diabetic peripheral neuropathy.Further in vitro experiments showed that overexpression of circ_0002538 promoted the migration of Schwann cells by upregulating plasmolipin(PLLP)expression.Moreover,overexpression of circ_0002538 in the sciatic nerve in a streptozotocin-induced mouse model of diabetic peripheral neuropathy alleviated demyelination and improved sciatic nerve function.The results of a mechanistic experiment showed that circ_0002538 promotes PLLP expression by sponging miR-138-5p,while a lack of circ_0002538 led to a PLLP deficiency that further suppressed Schwann cell migration.These findings suggest that the circ_0002538/miR-138-5p/PLLP axis can promote the migration of Schwann cells in diabetic peripheral neuropathy patients,improving myelin sheath structure and nerve function.Thus,this axis is a potential target for therapeutic treatment of diabetic peripheral neuropathy.

Emodin attenuates inflammation and demyelination in experimental autoimmune encephalomyelitis

Emodin,a substance extracted from herbs such as rhubarb,has a protective effect on the central nervous system.However,the potential therapeutic effect of emodin in the context of multiple sclerosis remains unknown.In this study,a rat model of experimental autoimmune encephalomyelitis was established by immune induction to simulate multiple sclerosis,and the rats were intraperitoneally injected with emodin(20 mg/kg/d)from the day of immune induction until they were sacrificed.In this model,the nucleotide-binding domain-like receptor family pyrin domain containing 3(NLRP3)inflammasome and the microglia exacerbated neuroinflammation,playing an important role in the development of multiple sclerosis.In addition,silent information regulator of transcription 1(SIRT1)/peroxisome proliferator-activated receptor-alpha coactivator(PGC-1α)was found to inhibit activation of the NLRP3 inflammasome,and SIRT1 activation reduced disease severity in experimental autoimmune encephalomyelitis.Furthermore,treatment with emodin decreased body weight loss and neurobehavioral deficits,alleviated inflammatory cell infiltration and demyelination,reduced the expression of inflammatory cytokines,inhibited microglial aggregation and activation,decreased the levels of NLRP3 signaling pathway molecules,and increased the expression of SIRT1 and PGC-1α.These findings suggest that emodin improves the symptoms of experimental autoimmune encephalomyelitis,possibly through regulating the SIRT1/PGC-1α/NLRP3 signaling pathway and inhibiting microglial inflammation.These findings provide experimental evidence for treatment of multiple sclerosis with emodin,enlarging the scope of clinical application for emodin.

Poly-L-ornithine blocks the inhibitory effects of fibronectin on oligodendrocyte differentiation and promotes myelin repair

The extracellular matrix surrounding oligodendrocytes plays an important role during myelination and remyelination in the brain.In many cases,the microenvironment surrounding demyelination lesions contains inhibitory molecules,which lead to repair failure.Accordingly,blocking the activity of these inhibitory factors in the extracellular matrix should lead to more successful remyelination.In the central nervous system,oligodendrocytes form the myelin sheath.We performed primary cell culture and found that a natural increase in fibronectin promoted the proliferation of oligodendrocyte progenitors during the initial stage of remyelination while inhibiting oligodendrocyte differentiation.Poly-L-ornithine blocked these inhibitory effects without compromising fibronectin’s pro-proliferation function.Experiments showed that poly-L-ornithine activated the Erk1/2 signaling pathway that is necessary in the early stages of differentiation,as well as PI3K signaling pathways that are needed in the mid-late stages.When poly-L-ornithine was tested in a lysolecithin-induced animal model of focal demyelination,it enhanced myelin regeneration and promoted motor function recovery.These findings suggest that poly-L-ornithine has the potential to be a treatment option for clinical myelin sheath injury.

Mechanisms and treatment strategies of demyelinating and dysmyelinating Charcot-Marie-Tooth disease

Schwann cells,the myelinating glia of the peripheral nervous system,wrap axons multiple times to build their myelin sheath.Myelin is of paramount importance for axonal integrity and fast axon potential propagation.However,myelin is lacking or dysfunctional in several neuropathies including demyelinating and dysmyelinating Charcot-M arie-To oth disease.Charcot-Marie-To oth disease represents the most prevalent inherited neuropathy in humans and is classified either as axonal,demyelinating or dysmyelinating,or as intermediate.The demyelinating or dysmyelinating forms of Charcot-Marie-Tooth disease constitute the majority of the disease cases and are most frequently due to mutations in the three following myelin genes:peripheral myelin protein 22,myelin protein ze ro and gap junction beta 1(coding for Connexin 32) causing Charcot-M arie-Tooth disease type 1A,Charcot-Marie-Tooth disease type 1B,and X-linked Charcot-M arie-Tooth disease type 1,respectively.The resulting perturbation of myelin structure and function leads to axonal demyelination or dysmyelination and causes severe disabilities in affected patients.No treatment to cure or slow down the disease progression is currently available on the market,howeve r,scientific discoveries led to a better understanding of the pathomechanisms of the disease and to potential treatment strategies.In this review,we describe the features and molecular mechanisms of the three main demyelinating or dysmyelinating forms of Charcot-Marie-Tooth disease,the rodent models used in research,and the emerging therapeutic approaches to cure or counteract the progression of the disease.

X-linked Charcot-Marie-Tooth disease after SARS-CoV-2 vaccination mimicked stroke-like episodes: A case report

BACKGROUND Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) vaccinations have been administered worldwide, with occasional reports of associated neurological complications. Specifically, the impact of vaccinations on individuals with Xlinked Charcot-Marie-Tooth disease type 1(CMTX1) is unclear. Patients with CMTX1 can have stroke-like episodes with posterior reversible encephalopathy syndrome on magnetic resonance imaging(MRI), although this is rare.CASE SUMMARY A 39-year-old man was admitted with episodic aphasia and dysphagia for 2 d. He received SARS-CoV-2 vaccination 39 d before admission. Physical examination showed pes cavus and reduced tendon reflexes. Brain MRI showed bilateral, symmetrical, restricted diffusion with T2 hyperintensities in the cerebral hemispheres. Nerve conduction studies revealed peripheral nerve damage. He was diagnosed with Charcot-Marie-Tooth disease, and a hemizygous mutation in the GJB1 gene on the X chromosome, known to be pathogenic for CMTX1, was identified. Initially, we suspected transient ischemic attack or demyelinating leukoencephalopathy. We initiated treatment with antithrombotic therapy and immunotherapy. At 1.5 mo after discharge, brain MRI showed complete resolution of lesions, with no recurrence.CONCLUSION SARS-CoV-2 vaccination could be a predisposing factor for CMTX1 and trigger a sudden presentation.

Function of microglia and macrophages in secondary damage after spinal cord injury

Spinal cord injury （SCI） is a devastating type of neurological trauma with limited therapeutic op- portunities. The pathophysiology of SCI involves primary and secondary mechanisms of injury. Among all the secondary injury mechanisms, the inflammatory response is the major contrib- utor and results in expansion of the lesion and further loss of neurologic function. Meanwhile, the inflammation directly and indirectly dominates the outcomes of SCI, including not only pain and motor dysfunction, but also preventingneuronal regeneration. Microglia and macrophages play very important roles in secondary injury. Microglia reside in spinal parenchyma and survey the microenvironment through the signals of injury or infection. Macrophages are derived from monocytes recruited to injured sites from the peripheral circulation. Activated resident microglia and monocyte-derived macrophages induce and magnify immune and inflammatory responses not only by means of their secretory moleculesand phagocytosis, but also through their influence on astrocytes, oligodendrocytes and demyelination. In this review, we focus on the roles of mi- croglia and macrophages in secondary injury and how they contribute to the sequelae of SCI.

Electroacupuncture promotes peripheral nerve regeneration after facial nerve crush injury and upregulates the expression of glial cell-derived neurotrophic factor

The efficacy of electroacupuncture in the treatment of peripheral facial paralysis is known, but the specific mechanism has not been clarified. Glial cell-derived neurotrophic factor(GDNF) has been shown to protect neurons by binding to N-cadherin. Our previous results have shown that electroacupuncture could increase the expression of N-cadherin mRNA in facial neurons and promote facial nerve regeneration. In this study, the potential mechanisms by which electroacupuncture promotes nerve regeneration were elucidated through assessing the effects of electroacupuncture on GDNF and N-cadherin expression in facial motoneurons of rabbits with peripheral facial nerve crush injury. New Zealand rabbits were randomly divided into a normal group(normal control, n = 21), injury group(n = 45) and electroacupuncture group(n = 45). Model rabbits underwent facial nerve crush injury only. Rabbits in the electroacupuncture group received facial nerve injury, and then underwent electroacupuncture at Yifeng(TE17), Jiache(ST6), Sibai(ST2), Dicang(ST4), Yangbai(GB14), Quanliao(SI18), and Hegu(LI4; only acupuncture, no electrical stimulation). The results showed that in behavioral assessments, the total scores of blink reflex, vibrissae movement, and position of apex nasi, were markedly lower in the EA group than those in the injury group. Hematoxylin-eosin staining of the right buccinator muscle of each group showed that the cross-sectional area of buccinator was larger in the electroacupuncture group than in the injury group on days 1, 14 and 21 post-surgery. Toluidine blue staining of the right facial nerve tissue of each group revealed that on day 14 post-surgery, there was less axonal demyelination and fewer inflammatory cells in the electroacupuncture group compared with the injury group. Quantitative real time-polymerase chain reaction showed that compared with the injury group, N-cadherin mRNA levels on days 4, 7, 14 and 21 and GDNF mRNA levels on days 4, 7 and 14 were significantly higher in the electroacupuncture group. Western blot assay displayed that compared with the injury group, the expression of GDNF protein levels on days 7, 14 and 21 were significantly upregulated in the electroacupuncture group. The histology with hematoxylin-eosin staining and Nissl staining of brainstem tissues containing facial neurons in the middle and lower part of the pons exhibited that on day 7 post-surgery, there were significantly fewer apoptotic neurons in the electroacupuncture group than in the injury group. By day 21, there was no significantly difference in the number of neurons between the electroacupuncture and normal groups. Taken together, these results have confirmed that electroacupuncture promotes regeneration of peripheral facial nerve injury in rabbits, inhibits neuronal apoptosis, and reduces peripheral inflammatory response, resulting in the recovery of facial muscle function. This is achieved by up-regulating the expression of GDNF and N-cadherin in central facial neurons.

Optimal duration of percutaneous microballoon compression for treatment of trigeminal nerve injury

Percutaneous microballoon compression of the trigeminal ganglion is a brand new operative technique for the treatment of trigeminal neuralgia. However, it is unclear how the procedure mediates pain relief, and there are no standardized criteria, such as compression pressure, com- pression time or balloon shape, for the procedure. In this study, percutaneous microballoon compression was performed on the rabbit trigeminal ganglion at a mean inflation pressure of 1,005 ＋ 150 mmHg for 2 or 5 minutes. At 1, 7 and 14 days after percutaneous microballoon compression, the large-diameter myelinated nerves displayed axonal swelling, rupture and demy- elination under the electron microscope. Fragmentation of myelin and formation of digestion chambers were more evident after 5 minutes of compression. Image analyzer results showed that the diameter of trigeminal ganglion cells remained unaltered after compression. These experi- mental findings indicate that a 2-minute period of compression can suppress pain transduction. Immunohistochemical staining revealed that vascular endothelial growth factor expression in the ganglion cells and axons was significantly increased 7 days after trigeminal ganglion compression, however, the changes were similar after 2-minute compression and 5-minute compression. The upregulated expression of vascular endothelial growth factor in the ganglion cells after percu- taneous microballoon compression can promote the repair of the injured nerve. These findings suggest that long-term compression is ideal for patients with recurrent trigeminal neuralgia.

Neurological disorders and inflammatory bowel diseases

Extraintestinal manifestations occur in about one-third of patients living with inflammatory bowel disease(IBD) and may precede the onset of gastrointestinal symptoms by many years. Neurologic disorders associated with IBD are not frequent, being reported in 3% of patients, but they often represent an important cause of morbidity and a relevant diagnostic issue. In addition, the increasing use of immunosuppressant and biological therapies for IBD may also play a pivotal role in the development of neurological disorders of different type and pathogenesis. Hence, we provide a complete and profound review of the main features of neurological complications associated with IBD, with particular reference to those related to drugs and with a specific focus on their clinical presentation and possible pathophysiological mechanisms.

Tamoxifen:an FDA approved drug with neuroprotective effects for spinal cord injury recovery

Spinal cord injury（SCI） is a condition without a cure,affecting sensory and/or motor functions.The physical trauma to the spinal cord initiates a cascade of molecular and cellular events that generates a non-permissive environment for cell survival and axonal regeneration.Among these complex set of events are damage of the blood-brain barrier,edema formation,inflammation,oxidative stress,demyelination,reactive gliosis and apoptosis.The multiple events activated after SCI require a multi-active drug that could target most of these events and produce a permissive environment for cell survival,regeneration,vascular reorganization and synaptic formation.Tamoxifen,a selective estrogen receptor modulator,is an FDA approved drug with several neuroprotective properties that should be considered for the treatment of this devastating condition.Various investigators using different animal models and injury parameters have demonstrated the beneficial effects of this drug to improve functional locomotor recovery after SCI.Results suggest that the mechanism of action of Tamoxifen administration is to modulate anti-oxidant,anti-inflammatory and anti-gliotic responses.A gap of knowledge exists regarding the sex differences in response to Tamoxifen and the therapeutic window available to administer this treatment.In addition,the effects of Tamoxifen in axonal outgrowth or synapse formation needs to be investigated.This review will address some of the mechanisms activated by Tamoxifen after SCI and the results recently published by investigators in the field.

Potential implications of Helicobacter pylori-related neutrophil-activating protein

Helicobacter pylori （H. pylori） virulence factors pro- mote the release of various chemoattractants/inflam- matory mediators, including mainly the neutrophil- attractant chemokine interleukin-8 and neutrophil- activating protein （NAP）, involved in H. pylor/-induced gastric pathologies. Co-administration of Chios mastic gum （CMG）, which inhibits H. pylor/NAP, with an H. pylori eradication regimen might add clinical benefits against H. pylori-related gastric pathologies, but pos- sibly not CMG as main therapy. Although H. pylori NAP and other H. pylori-related cytotoxins [i.e., vaculating cytotoxin （VacA）] appear to play a major role in gener- ating and maintaining the H. pylori-associated gastric inflammatory response and H. pylor/NAP is a promising vaccine candidate against H. pylori infection （H. pylori-1）, concerns regarding its potential drawbacks, particularly neurogenic ones, due to possible cross- mimicry, should be considered. Possible cross-mimicry between H. p, vlor/ NAP and/or bacterial aquaporin （AQP） and neural tissues may be associated with the anti-AQP-4 antibody-related neural damage in multiple sclerosis （MS）/neuromyelitis optica patients. Moreover, the sequence homology found between H. pylori VacA and human Na＋/K＋-ATPase A subunit suggests that antibodies to VacA involve ion channels in abaxonal Schwann cell plasmalemma resulting in demyelination in some patients. A series of factors have been im- plicated in inducing blood-brain barrier （BBB） disrup- tion, including inflammatory mediators （e.g., cytokines and chemokines induced by H. pylor/-I） and oxidative stress. BBB disruption permits access of AQP4-specific antibodies and T lymphocytes to the central nervous system, thereby playing a major role in multiple sclero- sis pathogenesis. Relative studies show a strong asso- ciation between H. pylori-I and MS. H. pylor/-I induces humoral and cellular immune responses that, owing to the sharing of homologous epitopes （molecular mim- icry）, cross-react with components of nerves, thereby contributing and perpetuating neural tissue damage. Finally, H. pylori NAP also plays a possible pathoge- netic role in both gastric and colon oncogenesis.

The contribution of oligodendrocytes and oligodendrocyte progenitor cells to central nervous system repair in multiple sclerosis： perspectives for remyelination therapeutic strategies

Oligodencrocytes（OLs） are the main glial cells of the central nervous system involved in myelination of axons. In multiple sclerosis（MS）, there is an imbalance between demyelination and remyelination processes, the last one performed by oligodendrocyte progenitor cells（OPCs） and OLs, resulting into a permanent demyelination, axonal damage and neuronal loss. In MS lesions, astrocytes and microglias play an important part in permeabilization of blood-brain barrier and initiation of OPCs proliferation. Migration and differentiation of OPCs are influenced by various factors and the process is finalized by insufficient acummulation of OLs into the MS lesion. In relation to all these processes, the author will discuss the potential targets for remyelination strategies.

Imaging and clinical properties of inflammatory demyelinating pseudotumor in the spinal cord

Inflammatory demyelinating pseudotumor usually occurs in the brain and rarely occurs in the spinal cord. On imaging, inflammatory demyelinating pseudotumor appears very similar to intramedullary tumors such as gliomas. It is often misdiagnosed as intramedullary tumor and surgically resected. In view of this, the clinical and magnetic resonance imaging manifestations and the pathological fea- tures of 36 cases of inflammatory demyelinating pseudotumer in the spinal cord were retrospec- tively analyzed and summarized. Most of these cases suffered from acute or subacute onset and exhibited a sensofimotor disorder. Among them, six cases were misdiagnosed as having intrame- dullary gliomas, and inflammatory demyelinating pseudotumor was only identified and pathologically confirmed after surgical resection. Lesions in the cervical and thoracic spinal cord were common. Magnetic resonance imaging revealed edema and space-occupying lesions to varying degrees at the cervical-thoracic junction, with a predominant feature of non-closed rosette-like reinforcement （open-loop sign）. Pathological examination showed perivascular cuffing of predominantly dense lymphocytes, and demyelination was observed in six of the misdiagnosed cases. These re- sults suggest that tumor-like inflammatory demyelinating disease in the spinal cord is a kind of special demyelinating disease that can be categorized as inflammatory pseudotumor. These solitary lesions are easily confused with intramedullary neoplasms. Patchy or non-closed reinforcement （open-ring sign） on magnetic resonance imaging is the predominant property of inflammatory de- myelinating pseudotumor, and inflammatory cell infiltration and demyelination are additional patho- logical properties.

The Olig family affects central nervous system development and disease

Neural cell differentiation and maturation is a critical step during central nervous system devel-opment. The oligodendrocyte transcription family （Olig family） is known to be an important factor in regulating neural cell differentiation. Because of this, the Olig family also affects acute and chronic central nervous system diseases, including brain injury, multiple sclerosis, and even gliomas. Improved understanding about the functions of the Olig family in central nervous system development and disease will greatly aid novel breakthroughs in central nervous system diseases. This review investigates the role of the Olig family in central nervous system develop- ment and related diseases.

Brief electrical nerve stimulation enhances intrinsic repair capacity of the focally demyelinated central nervous system

Our lab has shown that brief electrical nerve stimulation(ES)has a dramatic impact on remyelination of lysophosphatidyl choline(LPC)-induced focally demyelinated rat peripheral nerves,while also inducing an axon-protective phenotype and shifting macrophages from a predominantly pro-inflammatory toward a pro-repair phenotype.Whether this same potential exists in the central nervous system is not known.Thus,for proof of principle studies,the peripheral nerve demyelination and ES model was adapted to the central nervous system,whereby a unilateral focal LPC-induced demyelination of the dorsal column at the lumbar enlargement where the sciatic nerve afferents enter was created,so that subsequent ipsilateral sciatic nerve ES results in increased neural activity in the demyelinated axons.Data reveal a robust focal demyelination at 7 days post-LPC injection.Delivery of 1-hour ES at 7 days post-LPC polarizes macrophages/microglia toward a pro-repair phenotype when examined at 14 days post-LPC;results in smaller LPC-associated regions of inflammation compared to non-stimulated controls;results in significantly more cells of the oligodendroglial lineage in the demyelinated region;elevates myelin basic protein levels;and shifts the paranodal protein Caspr along demyelinated axons to a more restricted distribution,consistent with reformation of the paranodes of the nodes of Ranvier.ES also significantly enhanced levels of phosphorylated neurofilaments detected in the zones of demyelination,which has been shown to confer axon protection.Collectively these findings support that strategies that increase neural activity,such as brief electrical stimulation,can be beneficial for promoting intrinsic repair following focal demyelinating insults in demyelinating diseases such as multiple sclerosis.All animal procedures performed were approved by the University of Saskatchewan's Animal Research Ethics Board(protocol#20090087;last approval date:November 5,2020).