Review
Neurosciences
Jonathan Lezmy, Julia J. Harris, David Attwell
Summary: Neural information processing in electronic computation is energetically expensive due to the coding of information in membrane voltage changes, primarily generated by passive ion movements and reversed by active ATP-dependent ion pumping. This article focuses on the energetic cost of brain activity related to glutamatergic synapses, addressing the optimization of synapse function through evolution by adjusting presynaptic release probability and postsynaptic glutamate receptor numbers.
Article
Chemistry, Multidisciplinary
Xiaofan Guo, Bowen Han, Wenhan Qiu, Peiran Deng, Songsen Fu, Jianxi Ying, Yufen Zhao
Summary: Traditionally, enzymatic assays require additional labels or reagents. This study presents a versatile method using P-31 NMR spectroscopy to directly evaluate phosphatase and kinase activities without the need for tags or additional reagents. The method's utility for inhibitor identification is also demonstrated.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Craig K. Docherty, Anastasiya Strembitska, Christa P. Baker, Fiona F. Schmidt, Kieran Reay, John R. Mercer
Summary: This study reveals the important role of the antiageing protein Klotho in atherosclerotic plaques, improving vascular smooth muscle cell phenotype and mediating energetic switching, which delays the consequences of plaque rupture and enhances cell survival.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Review
Biochemistry & Molecular Biology
Chiara Castellini, Settimio D'Andrea, Giuliana Cordeschi, Maria Totaro, Antonio Parisi, Giovanna Di Emidio, Carla Tatone, Sandro Francavilla, Arcangelo Barbonetti
Summary: Recent studies suggest that glycolysis plays an important role in mammalian spermatozoa, challenging the dogma that mitochondria are the main source of energy supporting sperm motility. Dysfunctional mitochondria in human sperm are believed to be the main site of reactive oxygen species (ROS) generation, which can negatively impact sperm integrity and function through a complex relationship with oxidative stress. Despite the presence of antioxidant factors, human sperm are particularly sensitive to oxidative stress, contributing significantly to male factor infertility.
Article
Medicine, General & Internal
Maria de Cassia Macedo, Matheus Almeida Souza, Kariny Realino Ferreira, Laura Oliveira Campos, Igor Sergio Oliveira Souza, Michelle Almeida Barbosa, Ciro Jose Brito, Leonardo Intelangelo, Alexandre Carvalho Barbosa
Summary: The study aimed to assess the validity and reliability of a low-cost hand-held push dynamometer in measuring compressive forces in different ranges. The results showed that the dynamometer had excellent consistency and agreement, as well as high correlation and determination coefficients. The device was found to be a valid method for assessing knee isometric strength, with portability, cost-effectiveness, and user-friendly interface.
Review
Medicine, General & Internal
Vasiliki Tsampasian, Donnie Cameron, Rashed Sobhan, George Bazoukis, Vassilios S. Vassiliou
Summary: The heart relies on efficient energy substrate utilization for normal function, and abnormalities in myocardial energetics can lead to heart failure symptoms. Phosphorus magnetic resonance spectroscopy (P-31 MRS) is the only non-invasive method available to evaluate myocardial metabolic state in vivo. This review summarizes the importance of myocardial energetics and provides a systematic review of studies utilizing P-31 MRS in various cardiac pathologies.
MEDICINA-LITHUANIA
(2023)
Article
Biochemistry & Molecular Biology
Xiao-Hong Zhu, Byeong-Yeul Lee, Paul Tuite, Lisa Coles, Abhishek G. Sathe, Chi Chen, Jim Cloyd, Walter C. Low, Clifford J. Steer, Wei Chen
Summary: Advanced MR-based metabolic imaging techniques were utilized to quantitatively assess metabolic and bioenergetic parameters in the brains of Parkinson's disease patients, revealing subtle defects in energy metabolism and mitochondrial function before neurological deficits or pathogenesis occur in these patients. This provides an exciting opportunity to better understand neurodegenerative diseases, their progression, and response to treatment.
Article
Geriatrics & Gerontology
Francesca V. Lopez, Andrew O'Shea, Jens T. Rosenberg, Christiaan Leeuwenburgh, Stephen Anton, Dawn Bowers, Adam J. Woods
Summary: Aging is associated with declines in mitochondrial efficiency and energy production which directly impacts the availability of ATP, crucial for cellular functions. This study found that higher frontal ATP levels, but not posterior ATP levels, were associated with better cognitive performance in healthy older adults. The findings suggest that cognition is related to ATP in the frontal cortex and have implications for understanding mitochondrial function and its impact on cognition.
FRONTIERS IN AGING NEUROSCIENCE
(2023)
Article
Geriatrics & Gerontology
Samrat Sheoran, Wouter A. J. Vints, Kristina Valatkeviciene, Simona Kusleikiene, Rymante Gleizniene, Vida J. J. Cesnaitiene, Uwe Himmelreich, Oron Levin, Nerijus Masiulis
Summary: Resistance training for 12 weeks in older adults improves brain metabolism and muscle functional characteristics.
Article
Microbiology
Boris Taillefer, Julien F. Giraud, Eric Cascales
Summary: Polymicrobial communities are influenced by interactions between different species, including the competition mediated by the type VI secretion system (T6SS). This study shows that the synthesis, assembly, contraction, and disassembly of T6SS do not result in a significant growth cost for enteroaggregative Escherichia coli.
JOURNAL OF BACTERIOLOGY
(2023)
Article
Chemistry, Physical
Dong-Hoon Yang, Young-Kyun Kim, Sun-Hong Park, Kee-Ahn Lee
Summary: This study investigated the enhancement of mechanical and thermal properties of a Cu-Ni-Sn-P alloy manufactured with selective laser melting (SLM) through aging treatment. The results showed that aging treatment significantly increased the mechanical properties and thermal conductivity of the alloy, with the sample undergoing a 2-hour aging treatment showing the most improvement.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Review
Geriatrics & Gerontology
Steven Jett, Camila Boneu, Camila Zarate, Caroline Carlton, Vibha Kodancha, Matilde Nerattini, Michael Battista, Silky Pahlajani, Schantel Williams, Jonathan P. Dyke, Lisa Mosconi
Summary: Evidence suggests that mitochondria play a central role in aging-related neurodegenerative diseases, including Alzheimer's disease. Dysfunction in mitochondrial function, energy metabolism, and oxidative damage are early events in the pathophysiology of AD and may occur before the formation of amyloid beta plaques. Current imaging methods, such as FDG PET, are limited in assessing oxidative phosphorylation, which is responsible for a majority of the brain's energy production. Therefore, there is a crucial need for non-invasive imaging tools, such as P-31-MRS, to measure mitochondrial processes and assess AD risk in the human brain.
FRONTIERS IN AGING NEUROSCIENCE
(2023)
Article
Urology & Nephrology
Dulcegleika Vilas Boas Sartori, Paulo Roberto Kawano, Hamilto Akihissa Yamamoto, Rodrigo Guerra, Pedro Rochetti Pajolli, Joao Luiz Amaro
Summary: As women age, the frequency of sexual activity and orgasm may decrease, but a relationship between sexual activity and PFMS remains apparent. Women who are sexually active and achieve orgasms show better PFM endurance.
INVESTIGATIVE AND CLINICAL UROLOGY
(2021)
Article
Chemistry, Physical
Ahmed H. Awad, Hassan A. El-Hofy, Akihiko Chiba, Mohamed Abdel-Hady Gepreel
Summary: This study investigated the effects of zirconium content and thermomechanical treatment on the properties of low-cost Ti-14Mn-(x)Zr alloys. It was found that appropriate zirconium content, hot forging, and aging improved the hardness, strength, and ductility of the alloys. The formation of a dual-phase structure in the alloy resulted in higher compressive yield stress and malleability, surpassing the performance of commercial alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Health Care Sciences & Services
Natalia Romero-Franco, Pedro Jimenez-Reyes, Juan C. Fernandez-Dominguez
Summary: This study aimed to evaluate the concurrent validity and reliability of a low-cost digital dynamometer for assessing maximal isometric strength in neck movements. The results showed nearly perfect correlation between the digital dynamometer and the isokinetic dynamometer, with high intertester and intratester reliability. In conclusion, the low-cost digital dynamometer demonstrated valid and reliable measurements of maximal isometric strength in neck movements.
JOURNAL OF MANIPULATIVE AND PHYSIOLOGICAL THERAPEUTICS
(2021)
Article
Cardiac & Cardiovascular Systems
J. C. Weavil, T. S. Thurston, T. J. Hureau, J. R. Gifford, P. A. Kithas, R. M. Broxterman, A. D. Bledsoe, J. N. Nativi, R. S. Richardson, M. Amann
Summary: HFpEF patients show similar central and peripheral fatigue development as healthy controls during exercise not limited by cardiac output at the same relative intensity. However, HFpEF patients exhibit a greater susceptibility to neuromuscular fatigue during exercise at a given absolute intensity, which impairs functional capacity. The compromised leg blood flow response likely contributes to the attenuated fatigue resistance in HFpEF patients.
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
(2021)
Article
Physiology
Thomas J. Hureau, Joshua C. Weavil, Simranjit K. Sidhu, Taylor S. Thurston, Van R. Reese, Jia Zhao, Ashley D. Nelson, Nathaniel M. Birgenheier, Russell S. Richardson, Markus Amann
Summary: The study demonstrated that intravenous vitamin C administration can enhance antioxidant capacity and reduce muscle fatigue in COPD patients, but it does not improve exertional dyspnea and exercise tolerance. This suggests that compromised redox balance plays a crucial role in fatigue development in COPD, while exertional dyspnea remains a significant limiting factor for exercise tolerance in these patients.
JOURNAL OF APPLIED PHYSIOLOGY
(2021)
Article
Physiology
Joshua C. Weavil, Taylor S. Thurston, Thomas J. Hureau, Jayson R. Gifford, Soheil Aminizadeh, Hsuan-Yu Wan, Robert H. Jenkinson, Markus Amann
Summary: This study examined the impact of aging on the elastic and resistive components of the work of breathing during locomotor exercise. The findings suggest that while aging exaggerates the total work of breathing at a given metabolic rate or ventilatory rate, this difference is abolished when exercise is conducted at a given operating lung volume.
JOURNAL OF APPLIED PHYSIOLOGY
(2022)
Article
Physiology
Joshua C. Weavil, Oh Sung Kwon, Ronald W. Hughen, Jie Zhang, Alan R. Light, Markus Amann
Summary: The exercise pressor reflex (EPR), a neurocirculatory control mechanism, is exaggerated in hypertensive humans and rats. Diseaserelated abnormalities within the afferent arm of the reflex loop, including mechano- and metabosensitive receptors located at the terminal end of group III/IV muscle afferents, may contribute to the dysfunctional EPR in hypertension. Using control (WKY) and spontaneous hypertensive (SHR) rats, we examined dorsal root ganglion (DRG) gene and protein expression of molecular receptors recognized as significant determinants of the EPR. The results indicate that there is higher protein expression of certain receptors in SHR, while mRNA levels are not different between the two groups. This suggests that posttranscriptional regulation of sensory receptor protein expression might be impaired in hypertension.
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
(2022)
Article
Neurosciences
Massimo Venturelli, Matthew J. Rossman, Stephen J. Ives, Joshua C. Weavil, Markus Amann, D. Walter Wray, Russell S. Richardson
Summary: This study aimed to investigate the effects of exercise-induced muscle sympathetic nerve activity (MSNA) on passive leg movement (PLM)-induced vasodilation, predominantly mediated by nitric oxide (NO). The results showed that exercise-induced sympathetic excitation significantly attenuated PLM-induced vasodilation, highlighting the dominant role of sympathetic nerve activity in regulating skeletal muscle vascular conductance.
AUTONOMIC NEUROSCIENCE-BASIC & CLINICAL
(2022)
Article
Neurosciences
Thomas J. Hureau, Ryan M. Broxterman, Joshua C. Weavil, Matthew T. Lewis, Gwenael Layec, Markus Amann
Summary: This study investigated the relationship between intramuscular metabolites and neuromuscular function during exercise. The results suggest that intramuscular inorganic phosphate is the primary cause of peripheral fatigue, and muscle acidosis contributes to central fatigue.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Sport Sciences
Fabio Giuseppe Laginestra, Alessandro Cavicchia, Jennifer E. Vanegas-Lopez, Chiara Barbi, Camilla Martignon, Gaia Giuriato, Anna Pedrinolla, Markus Amann, Thomas J. Hureau, Massimo Venturelli
Summary: This study aimed to investigate the impact of central motor drive during fatiguing exercise on subsequent endurance task performance and neuromuscular fatigue development. The results suggest that central motor drive has a negligible effect on endurance performance, with peripheral fatigue being the primary determinant.
MEDICINE & SCIENCE IN SPORTS & EXERCISE
(2022)
Article
Neurosciences
Hsuan-Yu Wan, Joshua C. Weavil, Taylor S. Thurston, Vincent P. Georgescu, Candice K. Morrissey, Markus Amann
Summary: There are differences in cardiovascular responses between men and women in response to muscle mechanorellex (MMR) and chemorellex (CR) activation. The interaction between these reflexes and its hemodynamic consequences vary between the sexes. The activation of MMR and CR by passive leg movement and exposure to hypoxia or hypercapnia showed additive effects in men and hyper-additive effects in women. The interaction of MMR and CR has significant influence on autonomic cardiovascular control, with responses differing between men and women.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Review
Neurosciences
Markus Amann, Simranjit K. Sidhu, Chris J. McNeil, Simon C. Gandevia
Summary: This review summarizes the changes in the corticomotoneuronal pathway during different types of exercise and discusses their relevance to the development of central fatigue, as well as the potential of non-invasive brain stimulation to enhance exercise performance.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Letter
Neurosciences
Markus Amann, Simranjit Sidhu, Chris McNeil, Simon Gandevia
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Review
Cardiac & Cardiovascular Systems
Hsuan-Yu Wan, Kanokwan Bunsawat, Markus Amann
Summary: The cardiovascular response to exercise is regulated by neurocirculatory control mechanisms, including central command, baroreflex, exercise pressor reflex, and arterial chemoreflex. These mechanisms modulate autonomic nervous system activity, influencing cardiac output and vascular resistance to ensure adequate blood flow to active muscles and organs. The interaction of these mechanisms has recently gained recognition for its impact on circulation, especially in unique environments such as high altitude.
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
(2023)
Editorial Material
Neurosciences
Markus Amann, Simranjit K. Sidhu, Chris J. McNeil, Simon C. Gandevia
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Neurosciences
Taylor S. Thurston, Joshua C. Weavil, Vincent P. Georgescu, Hsuan-Yu Wan, Nathaniel M. Birgenheier, Candice K. Morrissey, Jacob E. Jessop, Markus Amann
Summary: This study investigated the role of the exercise pressor reflex (EPR) in regulating the cardiovascular response to locomotor exercise. The results showed that the EPR plays a critical role in the autonomic control of the heart, vasculature, and arterial pressure during exercise. However, it does not have a significant effect on leg blood flow in healthy, young individuals during exercise.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)