Biology-Basel最新文献

{"title":"Spatial Transcriptomics Reveals Regional and Temporal Dynamics of Gene Expression in the Mouse Brain Across Development and Aging.","authors":"Benjamin Conacher, Amanda Moore, Liduo Yin, Yu Lin, Xiguang Xu, Qinwen Mao, Hehuang Xie","doi":"10.3390/biology14060717","DOIUrl":"10.3390/biology14060717","url":null,"abstract":"<p><p>Investigating transcriptomic changes during healthy development and aging provides insights into the molecular mechanisms that regulate the maturation of brain functions and drive age-related decline. Although it has been speculated that aging may represent a reversal of late-stage brain development, direct molecular comparisons between these two processes have remained limited. This study employs spatial transcriptomics to analyze the mouse brain at three key timepoints: postnatal day 21 (P21), 3 months (adult), and 28 months (aged), to identify region-specific differential gene expression dynamics. We identify widespread transcriptional changes across both brain development and aging, with all brain regions exhibiting distinct, region-specific gene expression dynamics that reflect divergent regulatory trajectories across the lifespan. During development, gene expression patterns were strongly enriched for neurogenesis, synaptic plasticity, and myelination, reflecting active circuit formation and white matter maturation. In contrast, aging was characterized by a decline in myelination-related gene expression and a pronounced increase in inflammatory and glial activation pathways, particularly within the hippocampus. While both development and aging involved changes in myelination-associated genes, the underlying mechanisms appear distinct: developmental upregulation supports circuit establishment and refinement, whereas aging-related downregulation may reflect secondary consequences of neuroinflammation and reactive gliosis. These findings underscore that, despite some overlap in affected pathways, neural maturation and age-related decline are driven by fundamentally different regulatory programs. These findings establish a novel spatial transcriptomic reference for brain development and aging, offering a valuable data resource for investigating neurodevelopmental and neurodegenerative mechanisms.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility of Multiplex Cytokine Profiling in Preterm Labor: Towards Biomarker Discovery.","authors":"Ruth Llano, Inés Ardao, José Manuel Brea, Luz Romero, María P Pata, Antón L Martínez, Manuel Macía, María Isabel Loza","doi":"10.3390/biology14060714","DOIUrl":"10.3390/biology14060714","url":null,"abstract":"<p><p>Preterm delivery affects approximately 10% of pregnancies worldwide and remains a major clinical challenge due to the lack of reliable early predictive tools. Existing strategies are often invasive, relying on blood or amniotic fluid samples and requiring complex processing. In this study, we describe a novel non-invasive approach based on the multiplex detection of inflammatory cytokines in small urine volumes from pregnant women. To account for clinical and temporal variability, we applied Generalized Additive Models for Location, Scale, and Shape (GAMLSS) to adjust for gestational age at sampling and obstetric factors. Correlation network analyses revealed cytokine interactions that distinguished preterm from term deliveries, with macrophage-derived cytokines-MIP-1α, MIP-1β, IL-15, and IL-22-emerging as central nodes. These findings highlight the involvement of the IL-1 pathway in the pathophysiology of preterm labor. Furthermore, urinary IL-5 and IL-31 levels correlated positively with pregnancy duration, whereas IL-1β and IL-1Ra in urine and TNFα in amniotic fluid showed inverse associations. Altogether, this non-invasive methodology provides insight into immune dynamics during pregnancy and offers a foundation for future studies focused on biomarker discovery and mechanistic understanding of preterm birth.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189677/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-Hydroxyacyl CoA Dehydratase 2 Is Essential for Embryonic Development and Hepatic Metabolic Function Under a Low-Fat, High-Carbohydrate Diet.","authors":"Lengyun Wei, Fengli Wang, Luoxue Hua, Qun Wang, Benfei Hu, Ziye Yang, Letao Li, Chenfeng Liu, Kezhen Wang","doi":"10.3390/biology14060712","DOIUrl":"10.3390/biology14060712","url":null,"abstract":"<p><p>The conversion of carbohydrates into fatty acids is central for energy storage and the development and functioning of organs. Our previous study revealed that <i>Hacd2</i> deficiency alleviates the fatty liver and diabetes induced by HFD. This study aimed to explore the roles of Hacd2 in organ development and metabolic homeostasis under an LFHCD, which still need to be more deeply explored. We found that the germline deletion of <i>Hacd2</i> impairs long-chain fatty acid synthesis, which caused embryonic abnormalities after 7.5 days and led to embryonic lethality, as confirmed via photograph and hematoxylin-eosin staining. We next constructed <i>Hacd2LKO</i> mice and found that <i>Hacd2LKO</i> mice were largely normal when fed a chow diet, except for reduced inguinal white adipose tissue formation and glucose metabolism. Meanwhile, under an LFHCD, <i>Hacd2</i> deletion markedly controlled body weight and white adipose tissue formation, leading to lower cholesterol and triglycerides in serum; however, it unexpectedly resulted in enlarged liver volume, hepatocyte swelling and nuclear abnormalities, and infiltration of inflammatory cells, including macrophages, neutrophils and dendritic cells. Furthermore, inhibition of Hacd2 also reduced triglyceride levels and the expression of related lipogenic genes during adipocyte differentiation, as confirmed via RNA interference analysis. These findings highlight the critical roles of Hacd2 in embryonic development and metabolic diseases, revealing its protective function in maintaining liver homeostasis under an LFHCD. Therefore, targeted interventions involving Hacd2 for metabolic diseases must take into account dietary changes and the functioning of the liver.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189038/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vegetation Analysis of Wetland Ecosystems in Southern Turkey Using the Fuzzy Means Method.","authors":"Deniz Boz","doi":"10.3390/biology14060710","DOIUrl":"10.3390/biology14060710","url":null,"abstract":"<p><p>In this study, the vegetation of the natural area of the Göksu Delta Special Environmental Protection Agency (SEPA), one of Turkey's most important wetlands, is researched. The importance of this study in terms of contributing to environmental protection and land use planning studies reveals that this natural area, where rare ecosystems are found, has started to degrade and disappear under human influence. This study was conducted because the area is not only a designated RAMSAR wetland (a wetland site designated of international importance especially for the Waterfowl Habitat under the Ramsar Convention) but also includes nearby residential developments. With this study, the vegetation of the area was studied to determine the syntaxonomic units across different habitats. The natural area of Göksu Delta is divided into three main habitat groups: aquatic, sand dune, and halophytic. In the research, the Braun-Blanquet method was used. During the research in the Göksu Delta, 279 sample areas were surveyed. The data were analysed according to the fuzzy means cluster method. During the investigation, 29 associations were identified, and 16 of them are considered a new finding for science. These 29 associations can be classified as follows: aquatic vegetation is represented with four associations (three of them belong to <i>Phragmito-Magnocaricetea</i> and one of them belongs to Potametea classes), sand dune vegetation is represented with 12 associations (belonging to Ammophiletea Br.-Bl. & Tüxen ex Westhoff, Dijk, & Passchier 1946 class), and halophytic vegetation is represented with 13 associations (six of them belong to Salicornietea fruticosae Br.-Bl. & Tüxen ex A. & O. Bolòs 1950, six of them belong to Juncetea maritimi Br.-Bl. in Br.-Bl., Roussine & Nègre 1952, and one of them belong to Molinio-Juncetea Br.-Bl. (1931) 1947 classes). Three (<i>Onopordum boissieri</i>, <i>Ambrosia maritima,</i> and <i>Chlamydophora tridentata</i>) of the endemics and rare plants that were explored during the study were recorded as new alliance characteristics.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189343/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the Defenses: A Current and Comprehensive Review of Coleoptera Carabidae Strategies.","authors":"Teresa Bonacci","doi":"10.3390/biology14060709","DOIUrl":"10.3390/biology14060709","url":null,"abstract":"<p><p>The Carabidae family, or ground beetles, is a wide and ecologically significant group within the Coleoptera order, known for its role as natural predators of agricultural pests and as bioindicators of ecosystem health. These beetles employ a variety of behavioral, morphological, and chemical defense strategies to protect themselves from predators. These mechanisms include gregariousness, stridulation, regurgitation, and chemical defenses, such as the secretion of irritating compounds from specialized glands. The defensive strategies of carabids are classified into passive and active systems, each with varying energetic costs. Chemical substances (e.g., Formic acid, Methacrylic acid, Tiglic acid, Ethacrilic acid, Isovaleric acid, Salicylaldehyde, 1,4-Benzoquinone, Toluquinone, 13-2Kt tridecan-2-one, Undecane, Tridecane, Pentadecane, M-cresol) are particularly important, as they serve to deter predators and combat pathogens like bacteria and fungi. Ground beetles utilize both polar and non-polar compounds in their defense, all contributing to their ecological success. This review explores the array of defensive mechanisms in the Carabidae family, highlighting experimental studies, field observations, and reviews published over the last five decades. The aim is to provide a comprehensive understanding of how these strategies enhance the survival and fitness of carabid beetles in their natural environments.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189720/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Physiological Effects of Whole-Body Vibration Combined with Other Exercise Modalities in Overweight and Obese Individuals: A Systematic Review.","authors":"Daniel Batouli-Santos, Ana Carolina Coelho-Oliveira, Vanessa Amaral Mendonça, Alexei Wong, Adérito Seixas, Ana Cristina Rodrigues Lacerda, Anelise Sonza, Ayman Alhammad, Mario Bernardo-Filho, Danúbia da Cunha de Sá-Caputo, Redha Taiar","doi":"10.3390/biology14060711","DOIUrl":"10.3390/biology14060711","url":null,"abstract":"<p><strong>Introduction: </strong>Emerging evidence indicates that whole-body vibration (WBV) may be a relevant adjunct in interventions targeting overweight and obese individuals. Moreover, WBV has been applied in combination with other exercise modalities and therapeutic strategies, with various physiological responses observed in this population.</p><p><strong>Objective: </strong>The current systematic review aimed to assess the physiological effects of WBV with other modalities of exercises in overweight and obese individuals.</p><p><strong>Methods: </strong>Searches in PubMed, Embase, Web of Science, Scopus, and Cochrane databases were conducted to assess physiological responses to the combination of WBV with other modalities of exercises in overweight and obese individuals. Publications were identified and the screening was performed by two reviewers, independently. Irrelevant studies were excluded based on the eligibility criteria.</p><p><strong>Results: </strong>Seven studies, analyzing different outcomes, were included, with a mean methodological quality score of 7. Four studies analyzed the acute effect and three studied the cumulative effect, with different intervention protocols. Increases in growth hormone (GH) concentrations and bioelectrical phase angles, and reductions in fat mass, blood triglycerides, and cholesterol concentrations, as well as blood pressure, heart rate, and arterial stiffness, were reported.</p><p><strong>Conclusions: </strong>WBV combined with other exercise modalities seems to promote important physiological responses in overweight and obese individuals. However, more large-scale, long-term randomized controlled trials with WBV and other modalities of exercises in overweight and obese cohorts are needed to corroborate and expand the findings of the current systematic review.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12190056/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-of-Day-Dependent Effects of Aerobic Exercise on Carotid Hemodynamics in Sedentary Adults.","authors":"Bingyi Shen, Haibin Liu, Shuying Zhang, Lihong Chen, Guangrui Yang","doi":"10.3390/biology14060713","DOIUrl":"10.3390/biology14060713","url":null,"abstract":"<p><p>Aerobic exercise (AE) modulates vascular function through hemodynamic responses, thereby influencing cardiovascular health and risk, with the circadian rhythm system playing a crucial role. This chronobiological study investigated diurnal variations in exercise-induced hemodynamic changes in the common carotid artery. In a randomized crossover trial, twenty-two sedentary adults completed eight AE interventions (one per laboratory visit day), with each session performed at one of eight evenly distributed time points (from 06:00 to 20:00). Vascular ultrasound imaging and hemodynamic parameter calculations were performed both pre- and post-exercise. Compared to other time points, AE at 06:00 and 18:00 induced a greater and more sustained increase in mean flow rate and wall shear stress (WSS). Moreover, AE at 06:00 was associated with a smaller increase in oscillatory shear index and a larger decrease in peripheral resistance compared to other time points. Exercise-induced hemodynamic responses exhibited significant temporal variations. These findings emphasize the importance of exercise timing in optimizing vascular benefits for sedentary individuals.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189158/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of cbbL Carbon-Sequestering Microorganisms to Simulated Warming in the River Source Wetland of the Wayan Mountains.","authors":"Shijia Zhou, Kelong Chen, Ni Zhang, Siyu Wang, Zhiyun Zhou, Jianqing Sun","doi":"10.3390/biology14060708","DOIUrl":"10.3390/biology14060708","url":null,"abstract":"<p><p>As a globally critical carbon reservoir, the response mechanism of wetland ecosystems to climate change on the Qinghai-Tibet Plateau (QTP) has attracted significant scientific scrutiny. This study investigated the temperature sensitivity of cbbL-harboring carbon-sequestering microbial communities and their coupling with carbon-nitrogen cycle dynamics through a simulated field warming experiment conducted in the Wayan Mountains' river source wetland in the northeastern QTP. Key findings revealed that warming markedly elevated Alpha diversity (ACE and Chao1 indices), whereas Shannon and Simpson indices remained stable, indicating that temperature increases primarily altered community composition by enhancing species richness rather than evenness. Taxonomic analysis demonstrated significant increases in the relative abundances of Cyanobacteria and Actinobacteria, while Proteobacteria retained dominance but exhibited reduced relative abundance. At the genus level, <i>Thioflexothrix</i>, <i>Ferrithrix</i>, and <i>Rhodospirillum</i> dominated the community, with <i>Thioflexothrix</i> and <i>Ferrithrix</i> showing warming-induced abundance increments. Functional predictions indicated that warming preferentially stimulated heterotrophic and photoheterotrophic functional guilds. Soil physicochemical analyses further revealed warming-driven increases in nitrate nitrogen (NN), total carbon (TC), and total nitrogen (TN), concurrent with decreased soil moisture. Redundancy analysis identified TC as the predominant determinant of microbial community structure (followed by TN > NN), while pH and ammonium nitrogen (AN) exerted comparatively limited influence. Strong positive correlations between microbial communities and carbon/nitrogen indicators suggested that enhanced carbon-nitrogen resource availability served as the central driver of community succession. These findings elucidate the temperature-responsive mechanisms of cbbL-type carbon-sequestering microorganisms in alpine wetlands, offering critical insights for the adaptive management of carbon cycling in high-altitude ecosystems and advancing strategies toward achieving carbon neutrality goals.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189711/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing LED Light Intensity and Photoperiod to Promote Growth and Rooting of Medicinal Cannabis in Photoautotrophic Micropropagation.","authors":"Juwen Liang, Fang Ji, Qing Zhou, Dongxian He","doi":"10.3390/biology14060706","DOIUrl":"10.3390/biology14060706","url":null,"abstract":"<p><p>Conventional micropropagation of cannabis struggles with excessive callus hyperhydration, slow growth, low rooting efficiency, and high contamination risk, all of which greatly restrict its feasibility for large-scale propagation. In contrast, photoautotrophic micropropagation (PAM) has emerged as an efficient and cost-effective propagation strategy that can significantly enhance plantlet growth and improve seedling quality by optimizing the LED lighting environment. This study investigated the effects of four light intensities (50, 100, 150, and 200 µmol m^-2 s^-1) and three photoperiods (16, 20, and 24 h d^-1) on the growth and rooting of two medicinal cannabis cultivars (the short-day cultivar 'Charlotte' and the day-neutral cultivar 'Auto Charlotte'). Cluster analysis revealed that plantlets grown under the photoperiod of 20 h d^-1 and light intensity of 100-150 µmol m^-2 s^-1 exhibited optimal growth performance in terms of plant height, root length, leaf number, leaf area, biomass, and root activity. Moreover, increasing the light intensity from 50 to 100-150 µmol m^-2 s^-1 significantly enhanced net CO₂ exchange rates by 41.5% and 204.9% for Charlotte and Auto Charlotte, respectively, along with corresponding increases in dry matter accumulation of 44.3% and 27.9%. However, the plantlets exhibited photooxidative damage under continuous lighting and light intensity of 200 µmol m^-2 s^-1, as evidenced by reduced photosynthetic pigment content and suppressed antioxidant enzyme activity. Therefore, PAM of medicinal cannabis is recommended under the LED lighting environment with light intensity of 100-150 µmol m^-2 s^-1 and photoperiod of 20 h d^-1 to achieve optimal growth and rooting. These findings provide essential technical support for the large-scale propagation of vigorous, disease-free female plantlets with well-developed root systems and high genetic uniformity, thereby meeting the stringent quality standards for planting materials in the commercial cultivation of cannabis for medical and pharmaceutical use.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189681/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proprioceptive Control of Muscle Activation in Aging: Implications for Balance and Fall Risk.","authors":"Łukasz Oleksy, Anna Mika, Martyna Sopa, Artur Stolarczyk, Olga Adamska, Joanna Zyznawska, Rafał Buryta, Paulina Ciepiela, Jarosław Witkowski, Renata Kielnar","doi":"10.3390/biology14060703","DOIUrl":"10.3390/biology14060703","url":null,"abstract":"<p><p>(1) Background: This study aimed to assess whether older adults exhibit greater discrepancies between intended and actual motor unit recruitment, which could affect the quality of muscle activation and potentially increase the risk of falls. (2) Methods: Forty-eight physically active older women were assessed (65 ± 6 years, 164 ± 6 cm, and 76 ± 7 kg). The bioelectrical activity (EMG) of the vastus lateralis oblique (VLO) and vastus medialis oblique (VMO) muscles were assessed during isometric testing with the knee joint bent to 75 degrees. The participants were instructed to press against a stable bar for 5 s at a specific percentage of their perceived force level (at 15%, 30%, and 60% of MVC) when the EMG activity was recorded. Balance was assessed using a stabilometric platform in a standing position. (3) Results: In all three thresholds, the bioelectrical activity of the VLO and VMO muscles significantly deviated from what was expected under the assumption of a nearly linear relationship between muscle force and bioelectrical activity. In each of the three thresholds, it did not exceed 10% MVC and significantly differed only between the 15% and 60% MVC thresholds. No significant differences were found between the dominant and non-dominant sides. A significant relationship was observed between the sway area (Area 95%) and the activity of the non-dominant limb VLO muscle. (4) Conclusions: Our results suggest that older adults experience deficits in muscle activation perception, leading to discrepancies between intended and actual muscle engagement, which may affect functional task performance and potentially increase fall risk.</p>","PeriodicalId":48624,"journal":{"name":"Biology-Basel","volume":"14 6","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189530/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144498748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}