LIU Wansu， as the foremost of the four great masters of the Jin-Yuan period， established the "theory of fire-heat'' and extended the fire-heat pathogenesis framework to the field of stroke， thereby forming the theory of ''fire-heat inducing stroke''. This achieved a paradigmatic shift in stroke etiology from ''exogenous wind inducing stroke'' to ''fire-heat inducing stroke''. This paper systematically reviews the developmental trajectory of LIU Wansu's ''fire-heat inducing stroke'' theory and explores the social background， academic origins， and core connotations of its theoretical construction. The study found that， based on the ''Nineteen Pathomechanisms'' in the Huangdi's Internal Classic （Huang Di Nei Jing） and combined with clinical practice， LIU Wansu proposed that fire-heat is the fundamental cause of stroke， and that the Six Climatic Factors and the Five Zhi-Emotions can all transform into fire. He further constructed a stratified syndrome differentiation and therapeutic system centered on clearing heat and purging fire， emphasizing differentiated treatment of exterior and interior syndromes， Six Meridians syndrome differentiation， and seasonally adjusted medication. This theory not only resolved the diagnostic and therapeutic dilemmas of febrile epidemic diseases during the Jin-Yuan period， but also exerted a profound influence on later physicians such as ZHANG Zihe and ZHU Danxi， thereby promoting the pluralistic development of stroke theory in traditional Chinese medicine （TCM）. Modern pharmacological research provides solid scientific evidence， confirming that the ''fire-heat'' pathological state is highly associated with key mechanisms such as excessive inflammatory responses， oxidative stress， and excitatory amino acid toxicity following cerebral ischemia. Heat-clearing and fire-purging prescriptions and agents， such as Huanglian Jiedu Tang and baicalin， can exert multi-target neuroprotective effects by regulating inflammatory signaling， enhancing antioxidant enzyme activity， and balancing neurotransmitters. This not only verifies the scientific basis of the ''fire-heat inducing stroke'' theory from a modern biological perspective but also provides conclusive evidence for the clinical application of heat-clearing and fire-purging therapy. LIU Wansu's ''fire-heat inducing stroke'' theory represents a major milestone in the historical understanding of stroke pathogenesis， and its academically transitional insights continue to hold core guiding value for the pattern identification and treatment of ischemic stroke today.

LIU Wansu， as the foremost of the four great masters of the Jin-Yuan period， established the "theory of fire-heat'' and extended the fire-heat pathogenesis framework to the field of stroke， thereby forming the theory of ''fire-heat inducing stroke''. This achieved a paradigmatic shift in stroke etiology from ''exogenous wind inducing stroke'' to ''fire-heat inducing stroke''. This paper systematically reviews the developmental trajectory of LIU Wansu's ''fire-heat inducing stroke'' theory and explores the social background， academic origins， and core connotations of its theoretical construction. The study found that， based on the ''Nineteen Pathomechanisms'' in the Huangdi's Internal Classic （Huang Di Nei Jing） and combined with clinical practice， LIU Wansu proposed that fire-heat is the fundamental cause of stroke， and that the Six Climatic Factors and the Five Zhi-Emotions can all transform into fire. He further constructed a stratified syndrome differentiation and therapeutic system centered on clearing heat and purging fire， emphasizing differentiated treatment of exterior and interior syndromes， Six Meridians syndrome differentiation， and seasonally adjusted medication. This theory not only resolved the diagnostic and therapeutic dilemmas of febrile epidemic diseases during the Jin-Yuan period， but also exerted a profound influence on later physicians such as ZHANG Zihe and ZHU Danxi， thereby promoting the pluralistic development of stroke theory in traditional Chinese medicine （TCM）. Modern pharmacological research provides solid scientific evidence， confirming that the ''fire-heat'' pathological state is highly associated with key mechanisms such as excessive inflammatory responses， oxidative stress， and excitatory amino acid toxicity following cerebral ischemia. Heat-clearing and fire-purging prescriptions and agents， such as Huanglian Jiedu Tang and baicalin， can exert multi-target neuroprotective effects by regulating inflammatory signaling， enhancing antioxidant enzyme activity， and balancing neurotransmitters. This not only verifies the scientific basis of the ''fire-heat inducing stroke'' theory from a modern biological perspective but also provides conclusive evidence for the clinical application of heat-clearing and fire-purging therapy. LIU Wansu's ''fire-heat inducing stroke'' theory represents a major milestone in the historical understanding of stroke pathogenesis， and its academically transitional insights continue to hold core guiding value for the pattern identification and treatment of ischemic stroke today.

ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

Objective To investigate the therapeutic effect of Huangkui capsules on targeted drug-related proteinuria in patients with hepatocellular carcinoma (HCC). Methods A retrospective analysis was conducted on clinical data of HCC patients with targeted drug-related proteinuria from June 2023 to December 2024 at Zhongshan Hospital, Fudan University. According to the treatment plan, patients were divided into the conventional treatment group and the Huangkui combination treatment group (Huangkui capsules combined with conventional treatment), and the clinical efficacy between the two groups was compared. The logistic regression analysis was used to identify the main factors affecting treatment efficacy. Results The Huangkui combination treatment group (n＝29) showed a significantly higher overall effective rate (79.3% vs 42.3%, P＝0.005), and an earlier proteinuria improvement (median time: 3 months vs 6 months, P＝0.008) than the conventional treatment group (n＝26) . The multivariate logistic regression analysis showed angiotensin-converting enzyme inhibitor (ACEI) or angiotensin Ⅱ receptor blocker (ARB) using (OR＝0.190, 95%CI 0.045-0.808, P＝0.025), targeted drug adjustment (OR＝0.132, 95%CI 0.030-0.581, P＝0.007), and Huangkui capsules using (OR＝0.168, 95%CI 0.039-0.730, P＝0.017) were protective factors for treatment efficacy of targeted drug-related proteinuria. Conclusions On the basis of conventional treatment, additive treatment with Huangkui capsules can alleviate targeted drug-related proteinuria faster and more effectively in HCC patients.

ObjectiveTo investigate whether Huanglian Jiedutang （HLJD） and its major active constituents （geniposide， baicalin， and berberine） can inhibit the inflammatory response of BV2 cells under lipopolysaccharide （LPS） stimulation via the high-mobility group protein B1 （HMGB1）/Toll-like receptor 4 （TLR4）/nuclear factor-κB （NF-κB） signaling pathway， and to explore differences in therapeutic efficacy among the three monomers， their combined formula， and HLJD under equal content ratios. MethodsBV2 microglial cells were used as the primary experimental model. Cell viability was assessed using the cell counting kit-8 （CCK-8） method to examine the effects of different concentrations of dimethyl sulfoxide （DMSO， 0.8%， 0.4%， 0.2%， 0.1%， and 0.05%） on cell viability. IncuCyte was employed to monitor the growth of cells under different concentrations of HLJD （200， 100， 50， 25， 12.5， 6.25 mg·L^-1）. Nitric oxide （NO） assay was used to screen the optimal HLJD concentration. High-performance liquid chromatography （HPLC） determined the content of geniposide， baicalin， and berberine in HLJD， and experimental groups were subsequently established according to the relative proportions of these constituents. CCK-8 assay evaluated cell viability under different treatments. Enzyme-linked immunosorbent assay （ELISA） measured levels of inflammatory factors （TNF-α， IL-1β， IL-6， IL-10） in the supernatant. Flow cytometry assessed the effects of treatments on M1-type polarization of BV2 cells. Western blot determined the expression levels of HMGB1， TLR4， and NF-κB-related proteins. ResultsCompared with the blank group， DMSO at concentrations ≤0.2% did not affect cell viability within 48 h. BV2 cell growth plateaued at 24 h after treatment with 200 mg·L^-1 HLJD. Under stimulation with 2 mg·L^-1 LPS， this concentration of HLJD effectively reduced NO release， and 6 h pre-treatment had a stronger inhibitory effect on NO than direct administration. HPLC results showed that 1 mg of HLJD freeze-dried powder contained approximately 24 μg of geniposide， 15 μg of baicalin， and 30 μg of berberine. Based on these ratios， experimental groups were blank， LPS （2 mg·L^-1）， HLJD （200 mg·L^-1）， monomer combination， geniposide （4.8 mg·L^-1）， baicalin （3 mg·L^-1）， and berberine （6 mg·L^-1）. The monomer combination group consisted of all three active constituents dissolved together. LPS and HLJD or its active constituents did not affect cell viability compared with the blank group. LPS significantly increased TNF-α， IL-1β， IL-6， and IL-10 in the supernatant （P<0.01）. HLJD and its active constituents significantly reduced pro-inflammatory factors TNF-α， IL-1β， and IL-6 （P<0.05， P<0.01） while upregulating anti-inflammatory IL-10 （P<0.01）， with the monomer combination showing the strongest effect （P<0.05， P<0.01）. Compared with the blank group， LPS significantly increased the proportion of CD80⁺CD86⁺ （M1-type） BV2 cells （P<0.01）. HLJD and its constituents partially inhibited M1 polarization （P<0.05， P<0.01）， with the monomer combination exhibiting the most pronounced effect （P<0.05， P<0.01）. Compared with the blank group， LPS upregulated HMGB1， TLR4， and NF-κB-related proteins （P<0.01）， whereas HLJD and its active constituents significantly reduced their expression （P<0.05， P<0.01）， with the monomer combination having the strongest regulatory effect （P<0.05， P<0.01）. ConclusionHLJD and its major active constituents （geniposide， baicalin， berberine） can inhibit LPS-induced inflammatory responses in BV2 cells. The combination of the three active constituents demonstrates the most potent anti-inflammatory effect， significantly attenuating M1-type polarization of BV2 cells via the HMGB1/TLR4/NF-κB signaling pathway.

Although global brain science research has progressed rapidly in recent decades, several fundamental questions in neuroscience remain unresolved. In particular, the physical mechanism underlying neural signal transmission remains controversial, and the carriers responsible for neural information storage and retrieval have not yet been fully clarified. These unresolved issues motivate us to re-examine the processes of neural information generation, transmission, integration, storage, and retrieval from multiple perspectives. A key observation is that neural electromagnetic activities are closely associated with time. Their duration, temporal structure, and dynamic evolution play crucial roles in neural information processing. In this work, we analyze neural electromagnetic activities from the perspective of temporal scales (referred to here as the “time course”). By reviewing and integrating findings from previous studies, we examine the characteristic time requirements and dynamic features of neural processes occurring at different stages of information processing. These stages include neural signal generation, signal transmission along axons, synaptic integration, synaptic plasticity, and memory formation and retrieval. Based on this temporal analysis, we outline a framework describing neural electromagnetic activities across a wide range of time scales, spanning from microseconds to minutes, hours, or even longer periods associated with long-term memory, which suggests that neural information processing involves multiple physical processes operating at different time levels. Rapid electromagnetic events may occur on microsecond scales, whereas electrophysiological phenomena such as action potentials typically last on the order of milliseconds. Longer time scales are associated with synaptic plasticity and memory-related processes. From this perspective, we propose that the physical carrier of neural information may be transient electromagnetic pulses with durations on the microsecond scale. In this framework, action potentials can be interpreted as the macroscopic electrophysiological manifestation of underlying electromagnetic processes triggered by ionic currents across neuronal membranes. Rather than being the fundamental neural signal itself, the action potential may represent a measurable membrane-level response associated with the successful activation of these electromagnetic events. Moreover, we discuss a possible mechanism for long-term memory storage. Considering the apparent temporal contradiction between the millisecond-scale excitation of neurons and the long-term persistence of memories, we believe that long-term memory information may be stored within neural network topologies formed by electrical synapse coupling. Such structures, referred to as electrically coupled memory networks (ECMNs), may enable neurons within the same network to respond rapidly and synchronously to stimuli, thereby facilitating efficient memory retrieval. Overall, this study emphasizes the importance of considering the temporal organization of neural electromagnetic activities when interpreting neural signaling mechanisms. It may provide new insights into the physical nature of neural information carriers and the mechanisms of memory storage and retrieval. Furthermore, highlighting the potential role of electromagnetic interactions in neural activity may contribute to the development of new theoretical frameworks and experimental approaches in neuroscience. Such perspectives may also offer valuable references for future research on neural coding, brain function mechanisms, and neuromodulation technologies.

Objective:To investigate the predictive value of pre-infarction angina(PIA)combined with serum lipo-protein-associated phospholipase A2(Lp-PLA2)for no-reflow during primary percutaneous coronary interven-tion(PCI)in elderly patients with new-onset acute ST-segment elevation myocardial infarction(STEMI).Meth-ods:A total of 189 patients who hospitalized because of acute STEMI and underwent primary PCI within 12h in De-partment of Cardiology,Cangzhou People's Hospital between January 2018 and December 2022 were enrolled.Ac-cording to their TIMI blood flow during PCI,the patients were divided into no reflow group(n=42)and normal re-flow group(n=147).The baseline data were compared between two groups.Multivariate Logistic regression analy-sis was used to analyze the risk factors of no-reflow during PCI.The receiver operating characteristic(ROC)curve was plotted to evaluate the predictive value of PIA and Lp-PLA2 for no-reflow.Results:PI A occurred in 73 cases(38.6％),and no reflow occurred in 42 cases(22.2％)during primary PCI.Compared with patients in normal re-flow group,those in no reflow group had significant higher Lp-PLA2[(341.33±98.32)ng/ml vs.(261.95±75.21)ng/ml]and onset to reperfusion time[(7.02±1.28)h vs.(5.14±1.48)h],and significant lower incidence of PIA(23.8％ vs.42.9％)(P＜0.05 or＜0.01).Multivariate Logistic regression analysis showed that Lp-PLA2(OR=1.528,95％CI 1.028～2.030,P＜0.001),onset to reperfusion time(OR=2.602,95％CI 1.848～3.665,P＜0.001)were independent risk factors for no reflow during PCI in elderly STEMI patients,while PIA was an inde-pendent protective factor(OR=0.261,95％CI 0.101～0.671,P=0.005).The area under ROC curve of Lp-PLA2 combined PIA was 0.863(95％CI 0.806～0.909),which was significantly higher than those of Lp-PLA2[0.733(95％CI 0.664～0.794),Z=2.690,P=0.007]and PIA alone[0.609(95％CI 0.535～0.679),Z=5.657,P＜0.001].Conclusion:Pre-infarction angina has an important protective effect on no-reflow in STEMI patients.High Lp-PLA2 and absence of pre-infarction angina at admission may be good predictors of no-reflow during primary PCI in elderly patients with newly-onset acute STEMI,and it contributes to risk stratification of high risk patients.

Objective To elucidate the effects and mechanisms of Biejiajian pill(BJJP)-containing serum on the malignant biological behaviors of hepatocellular carcinoma Huh7 cells.Methods This research knocked down CKLF-like MARVEL transmembrane domain containing 6(CMTM6)expression using a CMTM6-specific small interfering RNA(siRNA).Healthy Sprague-Dawley rats were used to prepare normal rat serum and low-(0.55 g/kg),medium-(1.1 g/kg),and high-(2.2 g/kg)BJJP-containing.Huh7 cells were cultured with normal fetal bovine serum(BC),normal rat serum(NC),and low-,medium-,and high-dose BJJP serum(LBJJP,MBJJP,and HBJJP,respectively).BJJP-containing serum and si-CMTM6 were applied to Huh7 cancer cells,and the proliferation,migration,and invasion abilities were evaluated by CCK-8 and Transwell assays,respectively.Protein expression levels of proliferating cell nuclear antigen(PCNA),epithelial-mesenchymal transition(EMT)markers,and CMTM6 were detected by Western blot.Results CMTM6 knockdown significantly reduced the mRNA and protein expression level of CMTM6 in Huh7 cells(P＜0.05).There were no significant differences between the BC and NC groups in terms of cell proliferation,migration,invasion,expression levels of PCNA,EMT markers,and CMTM6(all P＞0.05).BJJP-containing serum markedly inhibited Huh7 cell proliferation,migration,and invasion(P＜0.05),downregulated PCNA,CMTM6,N-cadherin,and Vimentin expression,and upregulated E-cadherin compared with the NC group(all P＜0.05).CMTM6 knockdown suppressed malignant behaviors,with reduced PCNA,Vimentin,and N-cadherin and elevated E-cadherin expression(all P＜0.05).Conclusions BJJP-containing serum can significantly inhibit Huh7 cell growth,invasion,migration,and EMT progression,potentially mediated via CMTM6 suppression.

Objective To develop and validate a transgenic mouse model enabling specific and inducible optogenetic activation of oligodendrocyte precursor cells(OPCs).Methods A conditional allele for the photosensitive opsin chicken opsin 5(cOpn5)(Rosa26-LSL-cOpn5)was generated using CRISPR/Cas9 technology.These mice were subsequently crossed with NG2-CreERT transgenic mice to produce NG2-CreERT;cOpn5 animals.In this model,tamoxifen administration induces Cre-mediated recombination,leading to specific expression of cOpn5 in NG2-positive OPCs.The specificity and efficiency of cOpn5 expression in OPCs were confirmed by immunofluorescent staining.Functional validation of light-induced OPC activation was performed by using calcium imaging in acute brain slices after stimulation with 470 nm blue light.Results Immunofluorescence analysis confirmed robust and specific expression of cOpn5 within NG2-positive OPCs in the brains of tamoxifen-treated NG2-CreERT;cOpn5 mice.Crucially,calcium imaging of acute brain slices from these mice demonstrated a significant increase in intracellular calcium levels in cOpn5-expressing OPCs upon stimulation with 470 nm blue light,indicating successful optogenetic activation.Conclusion We have successfully generated and validated a novel transgenic mouse model(NG2-CreERT;cOpn5)that permits specific and inducible optogenetic activation of OPCs.This model provides a novel tool for subsequent in vivo studies of the role and regulating mechanisms of OPCs in the central nervous system.