Chronic pain is a complex condition shaped by long-standing alterations in both physiological and psychological processes. Rather than representing a simple continuation of acute nociceptive signaling, chronic pain is increasingly understood as the outcome of progressive dysregulation within distributed neural systems that govern sensation, affect, motivation, and cognitive control. Neuroimaging and electrophysiological studies indicate that this state is accompanied by extensive plastic changes in deep brain structures and large-scale networks. Beyond well-described central sensitization processes, chronic pain is characterized by disrupted oscillatory rhythms and altered connectivity within large-scale brain networks, including thalamo-cortical circuits and prefrontal-limbic-reward networks. These findings support a conceptual shift from viewing chronic pain as a focal, lesion-driven phenomenon toward recognizing it as a disorder of distributed network pathology. Pharmacological treatments remain central to clinical practice, yet their long-term efficacy is often limited and frequently accompanied by substantial side effects. The ongoing concerns about opioid-related risks and the inadequate therapeutic response in a subset of patients highlight the need for safe, non-pharmacological approaches that can address not only pain but also comorbid disturbances in mood, sleep, and social functioning. Neuromodulation provides a promising path toward mechanism-based and non-pharmacological management of chronic pain by employing physical or chemical stimulation to alter the excitability and synchrony of specific neural populations within central, peripheral, and autonomic systems. While invasive deep brain stimulation demonstrates that targeting deep brain structures can be effective, its clinical application is restricted by surgical risks and cost, highlighting the importance of non-invasive techniques capable of reaching deep targets. Current non-invasive approaches, such as transcranial electric stimulation, are constrained by limited penetration depth and insufficient spatial precision. These limitations hinder reliable engagement of deep regions implicated in pain, including the thalamus and nucleus accumbens, and tend to produce broad, non-specific modulation of cross-network oscillatory activity. Temporal interference (TI) stimulation has emerged as a means of overcoming these obstacles. By delivering interacting high-frequency currents that generate a low-frequency envelope within the head, TI enables focal stimulation of deep targets while minimizing superficial current delivery. Recent multiscale modeling and animal studies indicate that TI exploits the nonlinear rectification properties of neuronal membranes in response to high-frequency carriers, as well as their phase-locked responses to low-frequency envelopes, to generate “peak-focused” electric fields in deep regions under relatively low superficial current loads. Moreover, TI appears to exhibit potential advantages in terms of cell-type selectivity and rhythm-specific engagement, including differential responses across neuronal subtypes and distinct coupling to θ-, β-, and γ-band oscillations. These features suggest a promising avenue for correcting abnormal rhythms and network dynamics that contribute to chronic pain. This review summarizes current knowledge of the neural mechanisms underlying chronic pain and recent advances in TI research. It examines functional disturbances across key pain-related regions and networks, outlines the principles and technical characteristics of TI, and discusses potential deep-brain targets and stimulation strategies relevant to chronic pain. Evidence to date indicates that TI, with its non-invasiveness, tolerability, and capacity for precise deep brain modulation, holds great promise for the management of treatment-resistant chronic pain and may evolve into a new generation of precise and efficient non-pharmacological analgesic strategies.

Chronic pain is a complex condition shaped by long-standing alterations in both physiological and psychological processes. Rather than representing a simple continuation of acute nociceptive signaling, chronic pain is increasingly understood as the outcome of progressive dysregulation within distributed neural systems that govern sensation, affect, motivation, and cognitive control. Neuroimaging and electrophysiological studies indicate that this state is accompanied by extensive plastic changes in deep brain structures and large-scale networks. Beyond well-described central sensitization processes, chronic pain is characterized by disrupted oscillatory rhythms and altered connectivity within large-scale brain networks, including thalamo-cortical circuits and prefrontal-limbic-reward networks. These findings support a conceptual shift from viewing chronic pain as a focal, lesion-driven phenomenon toward recognizing it as a disorder of distributed network pathology. Pharmacological treatments remain central to clinical practice, yet their long-term efficacy is often limited and frequently accompanied by substantial side effects. The ongoing concerns about opioid-related risks and the inadequate therapeutic response in a subset of patients highlight the need for safe, non-pharmacological approaches that can address not only pain but also comorbid disturbances in mood, sleep, and social functioning. Neuromodulation provides a promising path toward mechanism-based and non-pharmacological management of chronic pain by employing physical or chemical stimulation to alter the excitability and synchrony of specific neural populations within central, peripheral, and autonomic systems. While invasive deep brain stimulation demonstrates that targeting deep brain structures can be effective, its clinical application is restricted by surgical risks and cost, highlighting the importance of non-invasive techniques capable of reaching deep targets. Current non-invasive approaches, such as transcranial electric stimulation, are constrained by limited penetration depth and insufficient spatial precision. These limitations hinder reliable engagement of deep regions implicated in pain, including the thalamus and nucleus accumbens, and tend to produce broad, non-specific modulation of cross-network oscillatory activity. Temporal interference (TI) stimulation has emerged as a means of overcoming these obstacles. By delivering interacting high-frequency currents that generate a low-frequency envelope within the head, TI enables focal stimulation of deep targets while minimizing superficial current delivery. Recent multiscale modeling and animal studies indicate that TI exploits the nonlinear rectification properties of neuronal membranes in response to high-frequency carriers, as well as their phase-locked responses to low-frequency envelopes, to generate “peak-focused” electric fields in deep regions under relatively low superficial current loads. Moreover, TI appears to exhibit potential advantages in terms of cell-type selectivity and rhythm-specific engagement, including differential responses across neuronal subtypes and distinct coupling to θ-, β-, and γ-band oscillations. These features suggest a promising avenue for correcting abnormal rhythms and network dynamics that contribute to chronic pain. This review summarizes current knowledge of the neural mechanisms underlying chronic pain and recent advances in TI research. It examines functional disturbances across key pain-related regions and networks, outlines the principles and technical characteristics of TI, and discusses potential deep-brain targets and stimulation strategies relevant to chronic pain. Evidence to date indicates that TI, with its non-invasiveness, tolerability, and capacity for precise deep brain modulation, holds great promise for the management of treatment-resistant chronic pain and may evolve into a new generation of precise and efficient non-pharmacological analgesic strategies.

This study aimed to investigate the effects of acupuncture on dynamic changes in Ca²⁺, Na⁺, and H₂O₂ flux following eccentric exercise-induced muscle injury. The total of 324 healthy male Wistar rats were randomly divided into 6 groups: control group (C), eccentric exercise group (E), eccentric exercise with acupuncture group (EA), EA with TRP channel blocker group (EAT), EA with NOX2 blocker group (EAN) and EA with placebo group (EAP). Gastrocnemius muscles were subject to lengthening contractions with percutaneous electrical stimulation, followed by immediate pretreatment with blocking agents. After 30 min, acupuncture needling was administered to the gastrocnemius muscle, and real-time dynamic changes of Ca²⁺, Na⁺ and H₂O₂ flux were measured with non-invasive micro-test technique during the needle retention period, immediately, 3 h, 6 h, and 24 h post-extraction respectively. Results showed that compared with the E group, acupuncture significantly increased net Ca²⁺ efflux (P < 0.05), extended the period of net Na⁺ influx, and significantly decreased net H₂O₂ efflux (P < 0.05). However, these effects were significantly attenuated in the EAT and EAN groups, where excessive net H₂O₂ efflux was observed (P < 0.001). These findings indicate that acupuncture regulates the dynamic changes of Ca²⁺, Na⁺ and H₂O₂ flux by activating the TRP channels and interacting with NOX2 activity following eccentric exercise-induced skeletal muscle injury.
Animals ; Muscle, Skeletal/metabolism* ; Rats, Wistar ; Rats ; Male ; Calcium/metabolism* ; Hydrogen Peroxide/metabolism* ; Physical Conditioning, Animal ; Sodium/metabolism* ; Acupuncture Therapy ; NADPH Oxidase 2

Researchers commonly use cyclization recombination enzyme/locus of X-over P1 (Cre/loxP) technology-based conditional gene knockouts of model mice to investigate the functional roles of genes of interest in Sertoli and Leydig cells within the testis. However, the shortcomings of these genetic tools include high costs, lengthy experimental periods, and limited accessibility for researchers. Therefore, exploring alternative gene silencing techniques is of great practical value. In this study, we employed adeno-associated virus (AAV) as a vector for gene silencing in Sertoli and Leydig cells. Our findings demonstrated that AAV serotypes 1, 8, and 9 exhibited high infection efficiency in both types of testis cells. Importantly, we discovered that all three AAV serotypes exhibited exquisite specificity in targeting Sertoli cells via tubular injection while demonstrating remarkable selectivity in targeting Leydig cells via interstitial injection. We achieved cell-specific knockouts of the steroidogenic acute regulatory ( Star ) and luteinizing hormone/human chorionic gonadotropin receptor (Lhcgr) genes in Leydig cells, but not in Sertoli cells, using AAV9-single guide RNA (sgRNA)-mediated gene editing in Rosa26-LSL-Cas9 mice. Knockdown of androgen receptor ( Ar ) gene expression in Sertoli cells of wild-type mice was achieved via tubular injection of AAV9-short hairpin RNA (shRNA)-mediated targeting. Our findings offer technical approaches for investigating gene function in Sertoli and Leydig cells through AAV9-mediated gene silencing.
Animals ; Male ; Leydig Cells/metabolism* ; Mice ; Dependovirus/genetics* ; Sertoli Cells/metabolism* ; Gene Silencing ; Genetic Vectors ; Testis/cytology*

BACKGROUND: The association of systemic inflammatory response index (SIRI) with prognosis of coronary artery disease (CAD) patients has never been investigated in a large sample with long-term follow-up. This study aimed to explore the association of SIRI with all-cause and cause-specific mortality in a nationally representative sample of CAD patients from United States. METHODS: A total of 3386 participants with CAD from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 were included in this study. Cox proportional hazards model, restricted cubic spline (RCS), and receiver operating characteristic curve (ROC) were performed to investigate the association of SIRI with all-cause and cause-specific mortality. Piece-wise linear regression and sensitivity analyses were also performed. RESULTS: During a median follow-up of 7.7 years, 1454 all-cause mortality occurred. After adjusting for confounding factors, higher lnSIRI was significantly associated with higher risk of all-cause (HR = 1.16, 95% CI: 1.09-1.23) and CVD mortality (HR = 1.17, 95% CI: 1.05-1.30) but not cancer mortality (HR = 1.17, 95% CI: 0.99-1.38). The associations of SIRI with all-cause and CVD mortality were detected as J-shaped with threshold values of 1.05935 and 1.122946 for SIRI, respectively. ROC curves showed that lnSIRI had robust predictive effect both in short and long terms. CONCLUSIONS SIRI was independently associated with all-cause and CVD mortality, and the dose-response relationship was J-shaped. SIRI might serve as a valid predictor for all-cause and CVD mortality both in the short and long terms.

Aim To study the regulatory effect of acupuncture pretreatment on ferroptosis of nerve cells in rats with ischemic stroke.Methods Sixty SD rats were randomly divided into sham middle cerebral artery occlusion(MCAO)group,MCAO group,and acupuncture+MCAO group.In the acupuncture+MCAO group,the acupuncture points of DU26,PC6,and SP6,were selected for acupuncture pretreatment,once a day for a total of 5 days.After pre-treatment,MCAO or sham MCAO models were prepared.The Zausinger sextintegral method was used to score the neuro-logical function of rats,and the infarct volume of brain tissue was calculated by TTC staining.Electron microscopy was used to observe the pathomorphological changes of brain tissue.The iron content was detected by colorimetric method,the content of malondialdehyde(MDA)and glutathione(GSH)was determined by ELISA,and the expression of glutathione peroxidase 4(GPX4)was detected by immunofluorescence.Results Compared with the sham MCAO group,the MCAO group had a decrease in neurological function scores,a significant increase in infarct volume,a decrease in the number of mitochondria under electron microscopy,a rupture and vacuolization of the inner mitochondrial cristae,an in-crease in the contents of iron and MDA in brain tissue,and a decrease in GSH content and GPX4 expression.Compared with the MCAO group,the acupuncture+MCAO group had an increase in neurological function scores,a decrease in infarct volume,a large number of mitochondria under electron microscopy,a clear structure,a decrease or disordered arrangement of some mitochondrial crest structures,a decrease in the contents of iron and MDA in brain tissue,and an increase in GSH content and GPX4 expression.Conclusion Acupuncture pretreatment can alleviate neurological damage in rats,and its mechanism may be related to regulating iron,GSH and MDA contents in brain tissue,and GPX4 expression,improving cell antioxidant capacity and inhibiting nerve cell ferroptosis.

Objective:To explore the implementation effect of the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode in the course of laboratory diagnostics under the background of automatic laboratory.Methods:The"four-step teaching of encouraging and sharing"combined anchor-based teaching mode conducted teaching in course of laboratory diagnostics through carefully designed"anchors",self-directed learning,a second"anchor"placement,and outcome sharing.A total of 224 medical students of the 2021 and 2022 grades,who majored Chinese medicine in Beijing University of Chinese Medicine and conducted their internships in the Laboratory of Dongfang Hospital,Beijing University of Chinese Medicine from April 2023 to April 2025,were selected.According to different teaching modes,the 108 medical students of 2022 grade were divided into the combined teaching group that adopted the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode to conduct teaching,and 116 medical students of 2021 grade were divided into the conventional teaching group that adopted conventional teaching mode to conduct teaching.After completed the courses,the comprehensive competency of these students of two groups during the internship were measured,and the application effect of the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode was assessed by self-made survey questionnaire.Results:The scores of theoretical knowledge test and clinical case analysis assessment of the students of combined teaching group were respectively(44.19±2.36)and(48.20±1.52),all of which were higher than(38.36±2.14)and(37.56±2.47)of conventional teaching group,and the differences of them between two groups were statistically significant(t=28.72,55.71,P<0.05),respectively.In the combined teaching group,91.67%of the students expressed a preference for the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode.Conclusion:Under the background of automatic laboratory,the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode of laboratory diagnostics can effectively enhance students'transfer ability for knowledge,and strengthen their self-directed learning awareness,and lay a solid foundation for training clinical practice abilities of medical students.

Aim To study the regulatory effect of acupuncture pretreatment on ferroptosis of nerve cells in rats with ischemic stroke.Methods Sixty SD rats were randomly divided into sham middle cerebral artery occlusion(MCAO)group,MCAO group,and acupuncture+MCAO group.In the acupuncture+MCAO group,the acupuncture points of DU26,PC6,and SP6,were selected for acupuncture pretreatment,once a day for a total of 5 days.After pre-treatment,MCAO or sham MCAO models were prepared.The Zausinger sextintegral method was used to score the neuro-logical function of rats,and the infarct volume of brain tissue was calculated by TTC staining.Electron microscopy was used to observe the pathomorphological changes of brain tissue.The iron content was detected by colorimetric method,the content of malondialdehyde(MDA)and glutathione(GSH)was determined by ELISA,and the expression of glutathione peroxidase 4(GPX4)was detected by immunofluorescence.Results Compared with the sham MCAO group,the MCAO group had a decrease in neurological function scores,a significant increase in infarct volume,a decrease in the number of mitochondria under electron microscopy,a rupture and vacuolization of the inner mitochondrial cristae,an in-crease in the contents of iron and MDA in brain tissue,and a decrease in GSH content and GPX4 expression.Compared with the MCAO group,the acupuncture+MCAO group had an increase in neurological function scores,a decrease in infarct volume,a large number of mitochondria under electron microscopy,a clear structure,a decrease or disordered arrangement of some mitochondrial crest structures,a decrease in the contents of iron and MDA in brain tissue,and an increase in GSH content and GPX4 expression.Conclusion Acupuncture pretreatment can alleviate neurological damage in rats,and its mechanism may be related to regulating iron,GSH and MDA contents in brain tissue,and GPX4 expression,improving cell antioxidant capacity and inhibiting nerve cell ferroptosis.

Objective:To explore the implementation effect of the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode in the course of laboratory diagnostics under the background of automatic laboratory.Methods:The"four-step teaching of encouraging and sharing"combined anchor-based teaching mode conducted teaching in course of laboratory diagnostics through carefully designed"anchors",self-directed learning,a second"anchor"placement,and outcome sharing.A total of 224 medical students of the 2021 and 2022 grades,who majored Chinese medicine in Beijing University of Chinese Medicine and conducted their internships in the Laboratory of Dongfang Hospital,Beijing University of Chinese Medicine from April 2023 to April 2025,were selected.According to different teaching modes,the 108 medical students of 2022 grade were divided into the combined teaching group that adopted the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode to conduct teaching,and 116 medical students of 2021 grade were divided into the conventional teaching group that adopted conventional teaching mode to conduct teaching.After completed the courses,the comprehensive competency of these students of two groups during the internship were measured,and the application effect of the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode was assessed by self-made survey questionnaire.Results:The scores of theoretical knowledge test and clinical case analysis assessment of the students of combined teaching group were respectively(44.19±2.36)and(48.20±1.52),all of which were higher than(38.36±2.14)and(37.56±2.47)of conventional teaching group,and the differences of them between two groups were statistically significant(t=28.72,55.71,P<0.05),respectively.In the combined teaching group,91.67%of the students expressed a preference for the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode.Conclusion:Under the background of automatic laboratory,the"four-step teaching of encouraging and sharing"combined anchor-based teaching mode of laboratory diagnostics can effectively enhance students'transfer ability for knowledge,and strengthen their self-directed learning awareness,and lay a solid foundation for training clinical practice abilities of medical students.

Objective To investigate the effects of sakuranetin (SK) on motor functions in the mouse model of spinal cord injury (SCI) and decipher the mechanism. Methods Fifty-four C57BL/6J mice were randomized into sham,SCI,and SK groups.The mice in the sham group underwent only laminectomy at T9,while those in the SCI and SK groups were subjected to spinal cord contusion injury at T9.Behavioral tests were conducted at different time points after surgery to evaluate the motor functions of mice in each group.The pathological changes in the tissue were observed to assess the extent of SCI in each group.The role and mechanism of SK in SCI were predicted by gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses.Reverse transcription real-time fluorescence quantitative PCR,ELISA,and immunofluorescence were employed to evaluate the inflammation and activation of microglia in SCI mice.BV2 cells in vitro were classified into control (Con),lipopolysaccharide (LPS),and LPS+SK groups.The effects of SK intervention on the release of inflammatory cytokines and the activation of BV2 cells were evaluated.Furthermore,the phosphatidylinositol-3-kinase(PI3K)/protein kinase B (AKT) signaling pathway activator insulin-like growth factor-1 (IGF-1) was used to treat the SK-induced BV2 cells in vitro (SK+IGF-1 group),and SK was used to treat the IGF-1-induced BV2 cells in vitro (IGF-1+SK group).Western blotting was conducted for molecular mechanism validation. Results Behavioral tests and histological staining results showed that compared with the SCI group,the SK group exhibited improved motor abilities and reduced area of damage in the spinal cord tissue (all P<0.001).The GO enrichment analysis predicted that SK may be involved in the inflammation following SCI.The KEGG enrichment analysis predicted that SK regulated the PI3K/Akt pathway to exert the neuroprotective effect.The results from in vitro and in vivo experiments showed that SK lowered the levels of tumor necrosis factor-α,interleukin-6,and interleukin-1β and inhibited the activation of microglia (all P<0.05).The results of Western blotting showed that SK down-regulated the phosphorylation levels of PI3K and Akt (all P<0.001) and inhibited the IGF-1-induced elevation of PI3K and Akt phosphorylation levels (all P<0.001).Conversely,IGF-1 had the opposite effects (P=0.001,P<0.001).The results of reverse transcription real-time fluorescence quantitative PCR,ELISA,and immunofluorescence showed that the SK+IGF-1 group had higher levels of inflammatory cytokines and more activated microglia than the SK group(all P<0.05). Conclusion SK may suppress the activation of the PI3K/Akt pathway to inhibit the inflammation mediated by SCI-induced activation of microglia,ameliorate the pathological damage of the spinal cord tissue,and promote the recovery of motor functions in SCI mice.
Animals ; Spinal Cord Injuries/pathology* ; Mice ; Microglia/metabolism* ; Mice, Inbred C57BL ; Neuroinflammatory Diseases/pathology* ; Signal Transduction/drug effects* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Male ; Inflammation ; Lipopolysaccharides ; Insulin-Like Growth Factor I/metabolism* ; Disease Models, Animal