Frontiers in Physiology最新文献

{"title":"Anesthetic-mediated cardioprotection: from molecular mechanisms to clinical translation challenges.","authors":"Tingting Fu, Xiao Jia, Can Tang, Dan Yu, Hui Zhou, Xinghe Wang, Su Liu, Kunwei Wu","doi":"10.3389/fphys.2025.1688142","DOIUrl":"10.3389/fphys.2025.1688142","url":null,"abstract":"<p><p>Anesthetics have long been recognized as essential pharmacological agents for surgical procedures, primarily valued for their ability to induce unconsciousness and provide analgesia. However, emerging research over the past 3 decades has revealed an additional and potentially transformative property of certain anesthetics: their ability to protect the heart against ischemic injury. This comprehensive review examines the cardioprotective effects of both intravenous and volatile anesthetics, with particular focus on propofol, ketamine, isoflurane, and sevoflurane. We analyze the molecular mechanisms underlying their protective actions, including modulation of mitochondrial function, reduction of oxidative stress, and regulation of key survival pathways such as PI3K/Akt/GSK3βand p53 signaling. The review evaluates preclinical evidence from cellular and animal models, as well as clinical studies investigating anesthetic-mediated cardioprotection in cardiac surgery patients. Special attention is given to the phenomenon of anesthetic preconditioning and postconditioning, their comparative efficacy, and the challenges in translating these protective strategies into clinical practice. We also discuss emerging concepts such as the role of microRNAs in mediating anesthetic-induced protection and the potential cardioprotective benefits of anesthetic combinations. Finally, we identify critical gaps in current knowledge and propose future research directions that may enhance the clinical application of anesthetic-mediated cardioprotection.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1688142"},"PeriodicalIF":3.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12484132/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Configural analysis of dry-land strength and front crawl performance in adolescents.","authors":"Tianyi Gao, Jiawen Shen, Baojie Tang, Xinyuan Wu, Yifan Shi, Bo Huang","doi":"10.3389/fphys.2025.1631224","DOIUrl":"10.3389/fphys.2025.1631224","url":null,"abstract":"<p><strong>Introduction: </strong>Dry-land strength capacities play a crucial role in competitive swimming, especially in short-distance events where explosive force and coordination are decisive. However, most research has focused on isolated variables rather than exploring how combinations of strength attributes jointly influence performance. Competitive swimming performance is influenced by multiple interacting physical attributes, yet the specific combinations of dry-land strength capacities that contribute to short-distance front crawl performance in adolescents remain unclear.</p><p><strong>Methods: </strong>To address this gap, this study employs fuzzy-set Qualitative Comparative Analysis (fsQCA) to investigate the configurational relationships between dry-land strength parameters and 50-m front crawl swimming performance among adolescent competitive swimmers. Eighty-five adolescent competitive swimmers (n = 85; age: 15.0 ± 1.5 years; weight: 61.5 ± 9.6 kg) were categorized into three groups based on competition scores and underwent seven physical assessments, including deep squats, pull-ups, grip strength tests, medicine ball throws, progressive plank, and vertical jumps.</p><p><strong>Results: </strong>Using fsQCA 3.0 software, configuration analysis revealed six significant causal configurations explaining 72.7% of high-performance cases. Configurations S1a/S1b identified core conditions in deep squats, pull-ups, and grip strength, while S2a/S2b highlighted bench press and vertical jumps for enhancing stroke efficiency and start/turn acceleration. The S3/S4 configurations demonstrated unique contributions from whole-body coordination and vertical explosiveness, respectively.</p><p><strong>Discussion: </strong>Multifactor synergy is key to improving swimming performance, and different athletes may need an individualized training focus. Coaches should develop a training plan based on the specific needs of the athletes to maximize their potential.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1631224"},"PeriodicalIF":3.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12484033/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change-induced stress in the honey bee <i>Apis mellifera</i> L.- a genetic review.","authors":"Soledad Sagastume, Giovanni Cilia, Dora Henriques, Carlos Yadró, Miguel Corona, Mariano Higes, M Alice Pinto, Antonio Nanetti, Raquel Martín-Hernández","doi":"10.3389/fphys.2025.1623705","DOIUrl":"10.3389/fphys.2025.1623705","url":null,"abstract":"<p><p>Climate change is a powerful driver of stress, as it reinforces hotter and drier environments. For bees, the most concerning aspects of these new environmental conditions are the resistance and resilience of bees to changes in temperature, humidity and ultraviolet radiation, as well as the negative effect on diversity of food resources which can lead in nutritional stress. The climatic vulnerability of various bee species and subspecies varies worldwide, as they experience varying levels of stress and display distinct behaviors, weaknesses, and lifespans. To understand these differences, it is crucial to consider both the genetics and epigenetics of bees, as these factors play a key role in their response, resistance, and adaptation to new stressors. This review provides a guide of genetic and epigenetic markers involved in the cellular response of <i>Apis mellifera</i> to most common stressors derived from climate change. Understanding how the various molecular mechanisms interact to restore homeostasis during the stress response is essential for designing future studies based on molecular markers.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1623705"},"PeriodicalIF":3.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12484183/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MAF-net: multi-receptive attention fusion network with dual-path squeeze-and-excitation enhancement module for uterine fibroid segmentation.","authors":"Yun Jiang, Qiquan Zeng, Hongmei Zhou, Xiaokang Ding","doi":"10.3389/fphys.2025.1659098","DOIUrl":"10.3389/fphys.2025.1659098","url":null,"abstract":"<p><strong>Introduction: </strong>Uterine fibroids are one of the most common benign tumors affecting the female reproductive system. In clinical practice, ultrasound imaging is widely used in the detection and monitoring of fibroids due to its accessibility and non-invasiveness. However, ultrasound images are often affected by inherent limitations, such as speckle noise, low contrast and image artifacts, which pose a substantial challenge to the precise segmentation of uterine fibroid lesions. To solve these problems, we propose a new multi-receptive attention fusion network with dual-path SE-enhancement module for uterine fibroid segmentation.</p><p><strong>Methods: </strong>Specifically, our proposed network architecture is built upon a classic encoder-decoder framework. To enrich the contextual understanding within the encoder, we incorporate the multi-receptive attention fusion module (MAFM) at the third and fourth layers. In the decoding phase, we introduce the dual-scale attention enhancement module (DAEM), which operates on image representations at two different resolutions. Additionally, we enhance the traditional skip connection mechanism by embedding a dual-path squeeze-and-excitation enhancement module (DSEEM).</p><p><strong>Results and discussion: </strong>To thoroughly assess the performance and generalization capability of MAF-Net, we conducted an extensive series of experiments on the clinical dataset of uterine fibroids from Quzhou Hospital of Traditional Chinese Medicine. Across all evaluation metrics, MAF-Net demonstrated superior performance compared to existing state-of-the-art segmentation techniques. Notably, it achieved Dice of 0.9126, Mcc of 0.9089, Jaccard of 0.8394, Accuracy of 0.9924 and Recall of 0.9016. Meanwhile, we also conducted experiments on the publicly available ISIC-2018 skin lesion segmentation dataset. Despite the domain difference, MAF-Net maintained strong performance, achieving Dice of 0.8624, Mcc of 0.8156, Jaccard of 0.7652, Accuracy of 0.9251 and Recall of 0.8304. Finally, we performed a comprehensive ablation study to quantify the individual contributions of each proposed module within the network. The results confirmed the effectiveness of the multi-receptive attention fusion module, the dual-path squeeze-and-excitation enhancement module, and the dual-scale attention enhancement module.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1659098"},"PeriodicalIF":3.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12484120/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of resistance training on physical function is associated with changes in serum albumin redox state in middle-aged and older Japanese adults: a Quasi-experimental study.","authors":"Takuya Shibasaki, Hirohiko Nakamura, Yuka Kurosaka, Shuji Sawada, Kazuhiro Miyaji, Shuichi Machida","doi":"10.3389/fphys.2025.1649300","DOIUrl":"10.3389/fphys.2025.1649300","url":null,"abstract":"<p><strong>Background: </strong>Resistance training is important for improving physical function in middle-aged and older adults. The fraction of mercaptoalbumin in total serum albumin, represented as f(HMA), is an indicator of physical function and protein nutritional status in humans. However, it is unclear whether the effects of resistance training on physical function are associated with changes in f(HMA). This study was aimed at examining the relationship between f(HMA) and the effects of resistance training in healthy middle-aged and older Japanese adults.</p><p><strong>Methods: </strong>The study included 43 healthy community dwelling middle-aged and elderly individuals (10 males and 33 females, aged 67.3 ± 8.0 years). They were engaged in a low-load, body-weight-based resistance training program using an elastic band twice a week for 12 weeks under supervision. Anthropometric data, 6-meter gait speed, blood biochemistry, and dietary macronutrient intake were collected before and after the training intervention. The relationships between serum nutritional parameters and gait speed or their rate of change were examined using multivariate linear regression analysis.</p><p><strong>Results: </strong>Before intervention, f(HMA) showed a significant positive correlation with the usual (<i>β</i> = 0.326, <i>P</i> = 0.045) and maximum (<i>β</i> = 0.331, <i>P</i> = 0.036) gait speeds. The changing rate of maximal gait speed showed a significant positive correlation with the rate of increase in f(HMA) (<i>β</i> = 0.456, <i>P</i> = 0.004).</p><p><strong>Conclusion: </strong>Serum f(HMA) increased with improvements in physical function through resistance training in middle-aged and older adults.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1649300"},"PeriodicalIF":3.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12485620/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fusion-driven multimodal learning for biomedical time series in surgical care.","authors":"Jinshan Che, Mingming Sun, Yuhong Wang, Zhendan Xu","doi":"10.3389/fphys.2025.1605406","DOIUrl":"10.3389/fphys.2025.1605406","url":null,"abstract":"<p><strong>Introduction: </strong>The integration of multimodal data has become a crucial aspect of biomedical time series prediction, offering improved accuracy and robustness in clinical decision-making. Traditional approaches often rely on unimodal learning paradigms, which fail to fully exploit the complementary information across heterogeneous data sources such as physiological signals, imaging, and electronic health records. These methods suffer from modality misalignment, suboptimal feature fusion, and lack of adaptive learning mechanisms, leading to performance degradation in complex biomedical scenarios.</p><p><strong>Methods: </strong>To address these challenges, we propose a novel multimodal Deep Learning framework that dynamically captures inter-modal dependencies and optimizes cross-modal interactions for time series prediction. Our approach introduces an Adaptive Multimodal Fusion Network (AMFN), which leverages attention-based alignment, graph-based representation learning, and a modality-adaptive fusion mechanism to enhance information integration. Furthermore, we develop a Dynamic Cross-Modal Learning Strategy (DCMLS) that optimally selects relevant features, mitigates modality-specific noise, and incorporates uncertainty-aware learning to improve model generalization.</p><p><strong>Results: </strong>Experimental evaluations on biomedical datasets demonstrate that our method outperforms state-of-the-art techniques in predictive accuracy, robustness, and interpretability.</p><p><strong>Discussion: </strong>By effectively bridging the gap between heterogeneous biomedical data sources, our framework offers a promising direction for AI-driven disease diagnosis and treatment planning.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1605406"},"PeriodicalIF":3.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12484004/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of repeated sessions of dual-site anodal tDCS on post-exercise performance and subjective recovery in recreationally active females: a randomized controlled trial.","authors":"Shima Sharifi Melahbid, Ehsan Amiri, Vahid Tadibi, Daniel Gomes da Silva Machado","doi":"10.3389/fphys.2025.1649732","DOIUrl":"10.3389/fphys.2025.1649732","url":null,"abstract":"<p><strong>Background: </strong>Previous studies have investigated the effects of transcranial direct current stimulation (tDCS) on performance enhancement, but limited research has examined its impact on post-exercise recovery. This study aimed to assess the effects of three consecutive sessions of dual-site anodal tDCS, targeting the primary motor cortex (M1) and the left dorsolateral prefrontal cortex (L-DLPFC), on both subjective and objective recovery measures in recreationally active females.</p><p><strong>Methods: </strong>Twenty-five recreationally active females were randomly assigned to either an anodal tDCS group (n = 13) or a sham group (n = 12). Performance and recovery were assessed at three time points: (1) before tDCS intervention, (2) immediately after a fatigue-inducing time-to-exhaustion test, and (3) following a 24-h recovery period. Participants completed a 3-km cycling time trial (TT) and a Sargent Jump Test (SJT) at each assessment. Additionally, after 24 h of recovery, they completed the Total Quality Recovery (TQR) scale and the Wellbeing Questionnaire (WBQ). Following baseline measurements, participants received their assigned intervention, three consecutive daily stimulation sessions (2 mA, 20 min, targeting + F3/-AF8 and +Cz/-AFz simultaneously), before the fatigue-inducing task.</p><p><strong>Results: </strong>Both groups exhibited similar physiological and perceived exertion responses during the fatigue-inducing task (all p > 0.05). While the a-tDCS group showed significant improvements in 3-km TT performance at 24 h post-recovery compared to baseline (p < 0.001, 95% CI [-36.71, -11.33]) and post-fatigue (p < 0.001, 95% CI [-28.4, -8.96]), there were no between-group differences (p > 0.05). However, the tDCS group reported higher TQR scores than the sham group at 24 h (p = 0.046, 95% CI [0.000, 2.000]). No significant between-group differences were observed in explosive performance (SJT) or WBQ scores (all p > 0.05).</p><p><strong>Conclusion: </strong>Three sessions of dual-site a-tDCS targeting M1 and L-DLPFC may enhance perceived recovery (TQR) in recreationally active females, but do not significantly influence wellbeing (WBQ) or objective performance recovery measures. The benefit appears to be subjective only, without a measurable performance advantage.</p><p><strong>Clinical trial registration: </strong>The trial was registered in the Iranian Clinical Trial Registry (www.irct.behdasht.gov.ir, IRCT ID: IRCT20230925059509N1).</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1649732"},"PeriodicalIF":3.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12479521/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A perspective on competitive freeride skiing and snowboarding.","authors":"Eric Mulder, Hans-Christer Holmberg, Matej Supej","doi":"10.3389/fphys.2025.1627889","DOIUrl":"10.3389/fphys.2025.1627889","url":null,"abstract":"<p><p>Freeride skiing and snowboarding-collectively termed <i>competitive freeriding</i>-have evolved from niche extreme sports into formally recognized disciplines under the International Ski & Snowboard Federation (FIS). Unlike traditional alpine or freestyle events, competitive freeriding emphasizes creative line selection, technical execution, fluidity, style, and aerial maneuvers on natural, ungroomed mountain terrain. Athletes descend complex slopes based solely on visual inspection, without practice runs, facing unique physical and psychological challenges. This perspective article outlines the competition format and judging system, identifies key physiological and biomechanical demands, and reviews essential equipment and safety considerations. Despite growing popularity and institutional recognition, scientific research remains limited-primarily focused on avalanche risk and injury incidence-while other dimensions, such as psychological resilience, creative expression, and environmental connectedness, remain underexplored. Physiologically, competitive freeriders require high levels of eccentric and explosive strength, core stability, reactive control, and anaerobic endurance to navigate variable terrain and absorb impact during aerial maneuvers. Lower-extremity injuries-particularly anterior cruciate ligament (ACL) ruptures-are a major concern. Technological advances in drone-based filming, athlete monitoring, and protective equipment are reshaping freeride competition and broadcasting. As the sport moves toward potential Olympic inclusion, the central challenge lies in embracing innovation without compromising the core values of freedom, improvisation, and connection to the mountain environment.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1627889"},"PeriodicalIF":3.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12479406/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Small scale electrostatically-driven aerosol deposition in <i>airway-on-chip</i> models of bronchial constriction.","authors":"Ron Bessler, Tirosh Mekler, Rami Fishler, Oshri Farhana, Sigal Dhatavkar, Tamar Daniel, Bar Kalifa, Kenichiro Koshiyama, Netanel Korin, Josué Sznitman","doi":"10.3389/fphys.2025.1621177","DOIUrl":"10.3389/fphys.2025.1621177","url":null,"abstract":"<p><p>Obstructive pulmonary diseases, including asthma and chronic obstructive pulmonary disease are widespread and represent a major global health burden. Despite their impact, effective therapeutic delivery to the small airways using inhaled aerosols remains suboptimal. In this study, we present a novel <i>in vitro</i> airway-on-chip platform that mimics both normal and constricted small bronchial geometries to quantify the deposition charged and neutral polystyrene latex aerosol particles ranging from 0.2 to 2 µm. Analytical and numerical solutions were derived from dimensionless scaling laws to further support the experiments and predict deposition location. Our experiments showcase how electrostatic forces significantly alter deposition patterns across particle sizes in these small airways. For submicron particles, we observe the enhancement of proximal airway deposition due to the coupling of electrostatic-diffusive screening effects. For larger particles, which typically deposit only in the direction of gravity, the inclusion of electrostatic forces significantly extends their deposition footprint, enabling deposition even in orientations where gravitational sedimentation is not feasible. Constricted regions consistently exhibit lower deposition across all cases, the presence of electrostatic forces enhanced overall deposition, offering a potential strategy for targeting bronchioles. Together, these findings suggest that electrostatic attraction may be strategically leveraged to enhance aerosol targeting in the small airways, providing new opportunities for optimizing inhaled drug delivery in obstructive lung diseases.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1621177"},"PeriodicalIF":3.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12482922/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive evaluation of critical-size calvarial defect in athymic rat model.","authors":"Todd M Parco, Jon D Wagner, Pratish Parbhoo, Caroline Soviak, Yuan Hu, John T Araiza, Colin O'Beirne, Sehrish Javaid, Praveen Parachuru, Matthew Lewis, Carlos A Acosta, Rajendra Prasad Settem, Toshihisa Kawai, Umadevi Kandalam","doi":"10.3389/fphys.2025.1662424","DOIUrl":"10.3389/fphys.2025.1662424","url":null,"abstract":"<p><p>The critical size defect (CSD), which defines the threshold beyond which spontaneous healing fails, serves as a foundational tool in bone regeneration research. This study investigated calvarial CSDs in an athymic rat model to refine the definition, emphasize its significance, and address inconsistencies in experimental design across existing information. A 4.5 mm diameter calvarial defect was surgically created in athymic rats. Bone regeneration was assessed using micro-computed tomography (micro-CT) at 1, 4, and 8 weeks after the surgery, compared to the baseline (day 0) post-surgery. Histological assessment was performed using a standard hematoxylin and eosin (H&E) staining protocol at 8 weeks post-surgery. Quantitative data from micro-CT analysis revealed no increase in bone volume or percentage volume from day 0 to week 1. We observed bone regeneration initiated at week 4 and progressed through week 8, with healing percentages ranging from 0.1% to a maximum of 7%. Histological examination of tissue at week 8 revealed the presence of loose collagen fibers and interspersed fibroblasts, with no mineralization as observed. These findings confirm that the 4.5 mm defect in calvarial bone qualifies as a critical-size defect in the athymic rat model. The study enhances our understanding of bone healing dynamics in CSDs and provides a validated platform for evaluating novel regenerative therapies.</p>","PeriodicalId":12477,"journal":{"name":"Frontiers in Physiology","volume":"16 ","pages":"1662424"},"PeriodicalIF":3.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12479404/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}