1.The Potential and Challenges of Temporal Interference Stimulation in Chronic Pain Management
Hao-Qing DUAN ; Yu-Qi GOU ; Ya-Wen LI ; Li HU ; Xue-Jing LÜ
Progress in Biochemistry and Biophysics 2026;53(2):369-387
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.
2.The Potential and Challenges of Temporal Interference Stimulation in Chronic Pain Management
Hao-Qing DUAN ; Yu-Qi GOU ; Ya-Wen LI ; Li HU ; Xue-Jing LÜ
Progress in Biochemistry and Biophysics 2026;53(2):369-387
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.
3.WANG Xixing's Clinical Experience in Treating Immune Checkpoint Inhibitor-Related Pneumonitis Based on the Theory of "Cough Attributed to the Five Zang (脏) Organs"
Xue QI ; Xi YANG ; Xinyue WANG ; Dongxin ZHANG ; Yuxing MAO ; Yuankun HAN ; Wenbo ZHAI ; Boyang LYU ; Yifang LI ;
Journal of Traditional Chinese Medicine 2026;67(5):477-481
This paper summarizes Professor WANG Xixing's clinical experience in treating immune checkpoint inhibitor-related pneumonitis (CIP) based on the theory of "cough attributed to the five zang (脏) organs". Cough is a common predominant symptom of CIP. According to the theory of "cough attributed to the five zang organs", drug toxicity triggers cancer toxin, leading to disharmony among the five zang organs, and then lung failing to diffuse and govern descent as the core pathogenesis. Therefore, treatment should focus on harmonizing the five zang organs to restore the normal function of lung qi to diffuse and govern descent. In clinical practice, CIP can be classified into four syndrome patterns, including lung yin depletion, deficiency of both the lung and the spleen with phlegm-dampness, liver fire harassing the lung, and lung-kidney yin deficiency. Correspondingly, Chaimai Jinluo Runfei Decoction (柴麦金络润肺汤) is used to nourish yin and moisten the lung; Qigui Peitu Huayin Decoction (芪桂培土化饮汤) is used to fortify the spleen and tonify the lung, resolve dampness and dispel phlegm; Chaidan Shuyu Runjin Decoction (柴丹疏郁润金汤) is used to drain liver and clear the lung; and Dimai Jinshui Xiangsheng Decoction (地脉金水相生汤) is used to nourish the kidney and moisten the lung.
4.Prokaryotic expression of Echinococcus granulosus Polo-like kinase 2 and immunoprotective efficacy of its recombinant protein
Xue WANG ; Mingzhi YAN ; Wenjing QI ; Chuanchuan WU ; Guowu ZHANG ; An GENG ; Mengxiao TIAN ; Jun LI ; Wenbao ZHANG
Chinese Journal of Schistosomiasis Control 2026;38(2):184-193
Objective To prepare the recombinant Echinococcus granulosus Polo-like kinase 2 (rEgPLK2) protein and evaluate its immunoprotective efficacy against cystic echinococcosis, so as to provide insights into research and development of novel vaccines against echinococcosis. Methods The Polo-like kinase (PLK) protein sequences were retrieved from 12 species in the NCBI protein database, including E. granulosus and E. multilocularis. Multiple sequence alignment was performed using the Clustal Omega program, and structural visualization and homology analysis were conducted using the ESPript 3.2 program. The recombinant plasmid pET-30a-EgPLK2 was transformed into BL21(DE3) competent cells. Protein expression was induced with isopropyl-β-D-thiogalactoside (IPTG), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to characterize the expression and molecular weight of the rEgPLK2 protein. The purified rEgPLK2 protein was thoroughly emulsified with Freund’s complete adjuvant at a 1 : 1 volume ratio. Two New Zealand white rabbits were immunized with multipoint subcutaneous injection on the back at a dose of 300 μg per rabbit for primary immunization. For booster immunizations, the protein was emulsified with Freund’s incomplete adjuvant at a 1 : 1 volume ratio and administered on days 14, 28, and 42 after the primary immunization at a dose of 150 μg per rabbit. Serum was sampled from the rabbit ear vein on day 7 after the final immunization to yield anti-rEgPLK2 polyclonal antibodies. Antibody titer was determined by indirect enzyme-linked immunosorbent assay (ELISA), and antibody specificity was verified by Western blotting. The tissue localization of the EgPLK2 protein was detected in E. granulosus protoscoleces and adult worms using immunofluorescence assay (IFA). Eighteen 6- to 8-week-old female SPF-grade BALB/c mice were randomly divided into three groups, including the blank control group, rEgPLK2-ISA immunization group, and PBS-ISA adjuvant control group, of 6 mice each group. Mice in the rEgPLK2-ISA immunization group and PBSISA group received three primary immunizations via intramuscular injection, and animals in the rEgPLK2-ISA immunization group was inoculated with immunogens prepared by emulsifying rEgPLK2 protein with ISA 201 adjuvant at a 1 : 1 volume ratio (6 μg per mouse), while mice in the PBS-ISA adjuvant control group received an equal volume of PBS emulsified with ISA adjuvant at a 1 : 1 volume ratio. A fourth booster immunization was administered via intraperitoneal injection. Mice in the rEgPLK2-ISA immunization group received a booster immunization with 8 μg of rEgPLK2 protein per mouse, and animals in the PBS-ISA group received an equal volume of PBS, with immunizations given at 2-week intervals. Mice in the blank control group were given no treatment, and housed under standard conditions. Tail vein blood was collected from all mice 7 days after the final immunization, and levels of specific anti-rEgPLK2 IgG antibody and its subclasses (IgG1, IgG2a, IgG2b, IgG3) were measured by indirect ELISA. E. granulosus infection was modelled in mice through injection with 1 000 E. granulosus protoscoleces via intrahepatic portal vein in the rEgPLK2-ISA immunization group and PBS-ISA adjuvant control group 2 weeks after the last immunization. All mice were sacrificed and dissected. The number of cysts was counted in mouse livers, and the cyst reduction rate was calculated. Liver tissues were processed for paraffin sectioning and stained with hematoxylin and eosin (HE), and histopathological changes were examined under a light microscope. Results Sequence analysis revealed that EgPLK2 shared a high amino acid sequence homology with E. multilocularis PLK2 (EmPLK2) and contained the typical domains of the Polo-like kinase family, including the serine/threonine protein kinase catalytic domain (STKc) and Polo-box. The IPTG-induced rEgPLK2 protein was mainly expressed in the form of inclusion bodies, and the purified rEgPLK2 protein showed a relative molecular mass of approximately 70 kDa. The prepared rabbit anti-rEgPLK2 polyclonal antibody had a titer of 1 : 256 000, and Western blotting assay showed that this anti-body specifically recognized the rEgPLK2 protein with a relative molecular mass of approximately 70 kDa. Immunofluorescence assay showed that the EgPLK2 protein was localized in the excretory bladder and rostellum of E. granulosus protoscoleces, as well as the tegument, suckers, and inter-proglottid junctions of adult worms. Immunoprotective assay showed that the serum levels of specific anti-rEgPLK2 IgG, IgG1, IgG2a, and IgG2b antibodies were 2.92 ± 0.49, 0.33 ± 0.10, 0.31 (0.36), and 3.12 (1.73) in mice in the rEgPLK2-ISA immunization group, which were all significantly higher than those in the PBS-ISA adjuvant control group (0.14 ± 0.04, 0.07 ± 0.01, 0.12 ± 0.04, and 0.11 ± 0.04, respectively) (t = 19.28 and 8.46, Z = 3.75 and 4.15; all P values < 0.001); however, there was no significant difference in the serum anti-IgG3 antibody level between the rEgPLK2-ISA immunization group and the PBS-ISA adjuvant control group [0.07 (0.01) vs. 0.073 (0.07); Z = 0.69, P > 0.05)]. In the mouse model of E. granulosus infections, the area of hepatic lesions was reduced and the inflammatory infiltration was alleviated in the rEgPLK2-ISA immunization group than in the PBS-ISA adjuvant control group, and the number of hepatic cysts was higher in the PBS-ISA adjuvant control group than in the rEgPLK2-ISA immunization group [8.00 (2.00) vs. 1.00 (0.75); Z = −2.93, P < 0.01], with a cyst reduction rate of 80.40%. Indirect ELISA assay measured higher serum levels of specific anti-rEgPLK2 IgG (3.28 ± 0.48 vs. 0.11 ± 0.04; t = 15.86, P < 0.01), IgG1 (0.29 ± 0.02 vs. 0.09 ± 0.01; t = 15.67, P < 0.01), IgG2a [3.71 (1.09) vs. 0.08 (0.03); Z = 2.88, P < 0.01], and IgG2b antibodies [3.34 (1.01) vs. 0.08 (0.03); Z = 2.88, P < 0.01] in the rEgPLK2-ISA immunization group than in the PBS-ISA adjuvant control group, and there was no significant difference in the serum level of the specific anti-rEgPLK2 IgG3 antibody between the rEgPLK2-ISA immunization group and the PBS-ISA adjuvant control group (0.07 ± 0.01 vs. 0.07 ± 0.01; t = 1.29, P > 0.05). Conclusions The prokaryotic expression system has been successfully constructed for the EgPLK2 gene and the anti-rEgPLK2 polyclonal antibody has been obtained. The rEgPLK2 protein exhibits a high immunogenicity, and is effective to protect against E. granulosus infection, and inhibits cyst development, which is a promising candidate vaccine target against cystic echinococcosis.
5.Research progress on the pathogenesis of central retinal vein occlusion
Qi HAN ; Xue HAN ; Xingchen GUO ; Yuanhui YANG ; Yuanmin LI ; Yufang TENG
International Eye Science 2025;25(8):1261-1266
Central retinal vein occlusion(CRVO)is a retinal vascular disorder that significantly impairs vision, with its underlying mechanisms involving complex interactions across multiple biological systems. This article provides a systematic review of the pathological mechanisms associated with CRVO, emphasizing critical factors such as endothelial dysfunction, arteriosclerosis, thrombophilia, inflammation, and oxidative stress. The pathological mechanisms of CRVO are characterized by arteriosclerosis, which obstructs venous return through a dual mechanism involving mechanical compression and endothelin-1-mediated contraction; endothelial dysfunction, which exacerbates disturbances in blood flow; genetic and acquired coagulation abnormalities that disrupt hemostatic balance and promote thrombosis; and the synergistic effects of inflammation and oxidative stress that activate cytokines, thereby aggravating ischemia and vascular leakage. Innovatively, this review explores emerging mechanisms such as miRNA-mediated vascular regulation via exosomes, gut microbiota-retina crosstalk through the “gut-eye axis,” and systemic metabolic interactions that link local retinal lesions to broader dysregulation of CRVO. These insights underscore the importance of integrated eye-system interventions and provide a theoretical foundation for advancing early biomarker discovery, multitarget therapeutics, and personalized treatment paradigms. By bridging localized pathology and systemic mechanisms, this work promotes a transformative shift toward an integrative medicine model in the diagnosis and management of CRVO.
6.Influencing factors of bladder management practices in patients with spinal cord injury
Zhirong LUO ; Xuyan GUO ; Qi XUE ; Xiao TAN ; Yunhua JI ; Fuxun ZHANG ; Yong JIAO ; Bo ZHANG
Journal of Modern Urology 2025;30(4):284-289
Objective: To explore the key factors affecting the selection and effectiveness of bladder management modalities in patients with spinal cord injury,so as to provide reference for the optimization of individualized bladder management strategies. Methods: The clinical and follow-up data of 78 patients with spinal cord injury treated in our hospital during Jan.1,2013 and Dec.31,2022 were retrospectively analyzed.The distribution of bladder management modalities among different grades of injuries was analyzed. Bowker symmetry test was used to evaluate the difference between bladder management modalities at discharge and at the end of follow-up. Multiple linear regression was used to explore the influencing factors of bladder management effects. Plotting Kaplan-Meier survival curves were adopted to calculate the median time of changes in bladder management. Results: At discharge,there were 9 cases of self-catheterization,19 cases of intermittent catheterization,22 cases of reflexive voiding,26 cases of long-term catheterization,and 2 cases using urinary collector.At the end of follow-up,there were 15 cases of self-catheterization,8 cases of intermittent catheterization,34 cases of reflexive voiding,14 cases of long-term catheterization,and 7 cases using urinary collector.There was a significant difference between the modalities of bladder management at discharge and at the end of follow-up (χ
=21.43,P=0.018).Multiple linear regression showed a significant decrease of 8.60 in the total neurogenic bladder symptom score (NBSS) for grade D injuries compared with grade A injuries (P=0.026). The median time to bladder management change was 7.93 months (95%CI:5.44-9.44), with approximately 50% of patients experiencing a change in bladder management within 8 months after discharge. Conclusion: The modalities of bladder management changed significantly after discharge.The grade of injury was a key factor affecting the effectiveness of bladder management.Higher grade was associated with worse effectiveness of bladder management.
7.Analysis of the causal relationship between gut microbiota and bladder cancer with Mendelian randomization
Xuyan GUO ; Zhirong LUO ; Qi XUE ; Yunhua JI ; Xiao TAN ; Yong JIAO
Journal of Modern Urology 2025;30(5):400-407
Objective: Previous observational studies have confirmed the correlation between gut microbiota and bladder cancer,but the causal relationship is still unclear.This study aimed to explore the causal relationship between them with Mendelian randomization. Methods: Genetic variation summary data of 211 gut microbiota and bladder cancer genome-wide association studies (GWAS) were obtained from the MiBioGen Consortium and Finngen database.Single nucleotide polymorphisms (SNPs) closely related to these studies were screened as instrumental variables.The causal relationship between gut microbiota and bladder cancer were analyzed with inverse variance weighting (IVW),MR-Egger,weighted median,maximum likelihood,robust adjustment feature score and MR-PRESSO,with IVW as the primary analysis method.Additionally,sensitivity analysis was used to test the heterogeneity (Cochran Q) and horizontal pleiotropy (MR-Egger intercept term and global test from MR-PRESSO estimator) to ensure the robustness of the results. Results: The IVW results indicated that Lachnospiraceae UCG004 (OR:1.42),Desulfovibrionales (Order) (OR:1.48),Eubacterium ruminantium group (OR:1.33),Olsenella (OR:1.24),Ruminococcaceae UCG002 (OR:1.39),Ruminococcaceae UCG005 (OR:1.42) and Ruminococcaceae UCG013 (OR:1.64) significantly increased the risk of bladder cancer.Conversely,Bacteroidetes (Phylum) (OR:0.61),Eubacterium brachy group (OR:0.80),Ruminococcaceae UCG004 (OR:0.73),Rikenellaceae (Family) (OR:0.67),Lachnospiraceae ND3007 group (OR:0.47), Adlercreutzia (OR:0.73) and an unknow genus (OR:0.75) were associated with a reduced risk of bladder cancer.Sensitivity analyses did not reveal any heterogeneity or horizontal pleiotropy. Conclusion: This study reveals the causal role of 14 gut microbiota in the pathogenesis of bladder cancer,among which Lachnospiraceae UCG004,Desulfovibrionales (Order),Eubacterium ruminantium group,Olsenella,Ruminococcaceae UCG002,Ruminococcaceae UCG005 and Ruminococcaceae UCG013 are risk factors for bladder cancer,while Bacteroidetes (Phylum),Eubacterium brachy group,Ruminococcaceae UCG004,Rikenellaceae (Family),Lachnospiraceae ND3007 group,Adlercreutzia and an unknown genus are the protective factors.
8.Immunotherapy for Lung Cancer
Pei-Yang LI ; Feng-Qi LI ; Xiao-Jun HOU ; Xue-Ren LI ; Xin MU ; Hui-Min LIU ; Shou-Chun PENG
Progress in Biochemistry and Biophysics 2025;52(8):1998-2017
Lung cancer is the most common malignant tumor worldwide, ranking first in both incidence and mortality rates. According to the latest statistics from the International Agency for Research on Cancer (IARC), approximately 2.5 million new cases and around 1.8 million deaths from lung cancer occurred in 2022, placing a tremendous burden on global healthcare systems. The high mortality rate of lung cancer is closely linked to its subtle early symptoms, which often lead to diagnosis at advanced stages. This not only complicates treatment but also results in substantial economic losses. Current treatment options for lung cancer include surgery, radiotherapy, chemotherapy, targeted drug therapy, and immunotherapy. Among these, immunotherapy has emerged as the most groundbreaking advancement in recent years, owing to its unique antitumor mechanisms and impressive clinical benefits. Unlike traditional therapies such as radiotherapy and chemotherapy, immunotherapy activates or enhances the patient’s immune system to recognize and eliminate tumor cells. It offers advantages such as more durable therapeutic effects and relatively fewer toxic side effects. The main approaches to lung cancer immunotherapy include immune checkpoint inhibitors, tumor-specific antigen-targeted therapies, adoptive cell therapies, cancer vaccines, and oncolytic virus therapies. Among these, immune checkpoint inhibitors and tumor-specific antigen-targeted therapies have received approval from the U.S. Food and Drug Administration (FDA) for clinical use in lung cancer, significantly improving outcomes for patients with advanced non-small cell lung cancer. Although other immunotherapy strategies are still in clinical trials, they show great potential in improving treatment precision and efficacy. This article systematically reviews the latest research progress in lung cancer immunotherapy, including the development of novel immune checkpoint molecules, optimization of treatment strategies, identification of predictive biomarkers, and findings from recent clinical trials. It also discusses the current challenges in the field and outlines future directions, such as the development of next-generation immunotherapeutic agents, exploration of more effective combination regimens, and the establishment of precise efficacy prediction systems. The aim is to provide a valuable reference for the continued advancement of lung cancer immunotherapy.
9.Evaluation progress of the application of staplers in thoracoscopic lung surgery
Shenghui LI ; Yijiu REN ; Hang SU ; Minglei YANG ; Guofang ZHAO ; Yongxiang SONG ; Xuefei HU ; Deping ZHAO ; Qi XUE ; Chang CHEN
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(05):709-713
Compared to traditional suturing, lung stapling using automatic staplers offers advantages such as smaller trauma, faster wound healing, ease of operation, and lower complication rates, making it widely used in clinical practice. However, there are significant differences in bronchial tissue thickness at different anatomical locations, and the market is flooded with various types of staplers. Currently, there is a lack of recommended stapling schemes for bronchial staplers at different anatomical locations. This article reviews the development and application of automatic staplers and summarizes some types of staplers that are currently used in clinical practice, with the aim of promoting the formation of individualized stapler selection protocols for minimally invasive thoracic surgery based on the Chinese population.
10.Effects of Non-invasive Light Flicker on Functional Properties of Primary Visual Cortex in Adult Mice
Xue-Qi LI ; Yi-Feng ZHOU ; Guang-Wei XU
Progress in Biochemistry and Biophysics 2025;52(9):2360-2375
ObjectiveAs the central hub of the classical visual pathway, the primary visual cortex not only encodes and processes visual information but also establishes dense neural circuit connections with higher-order cognitive brain regions. Numerous studies have shown that 40 Hz flicker stimulation can induce γ oscillations in the brain and significantly improve learning and cognitive impairments in patients with neurodegenerative diseases. Moreover, flickering light phenomena naturally occur in daily environments. Given that the primary visual cortex serves as the brain’s first cortical hub for receiving visual input, it is essential to comprehensively understand how non-invasive light flicker stimulation modulates its information processing mechanisms. This study systematically investigates the effects of non-invasive light flicker stimulation at different frequencies on the functional properties of neurons in the primary visual cortex of adult mice, aiming to uncover how such stimulation modulates this region and, consequently, affects overall brain function. MethodsThree groups of adult mice (approximately 12 weeks old) were exposed to light flicker stimulation at frequencies of 20 Hz, 40 Hz, and 60 Hz, respectively, for a duration of two months. A control group was exposed to the same light intensity without flickering. Following the stimulation period, in vivo multi-channel electrophysiological recordings were conducted. During these recordings, anesthetized mice were presented with various types of moving sinusoidal light gratings to assess the effects of different flicker frequencies on the functional properties of neurons in the primary visual cortex. ResultsThe experimental results demonstrate that two months of light flicker stimulation at 20 Hz, 40 Hz, and 60 Hz enhances the orientation tuning capabilities of neurons in the primary visual cortex. Specifically, 40 Hz and 60 Hz stimulation improved contrast sensitivity, whereas 20 Hz had no significant effect. Further analysis revealed that all three frequencies reduced neuronal response variability (as measured by the Fano factor), increased the signal-to-noise ratio, and decreased noise correlation (rsc) between neurons. ConclusionNon-invasive light flicker stimulation enhances orientation tuning (e.g., orientation bias index) and contrast sensitivity (e.g., contrast threshold and C50) in neurons of the primary visual cortex. This enhancement is likely due to improved information processing efficiency, characterized by reduced neuronal variability and increased signal-to-noise ratio. These findings suggest that the primary visual cortex can achieve precise and efficient information encoding in complex lighting environments by selectively adapting to different flicker frequencies and optimizing receptive field properties. This study provides new experimental evidence on how various types of light flicker influence visual perception and offers insights into the mechanisms through which specific frequencies enhance brain function.

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