Patients with Parkinson's disease are unable to adjust the firing rate of motor units that initiate contraction from zero to higher rates; the frequency modulation of motor units is not normal, but motor units recruit normally as effort is increased. Treatment with levodopa makes these motor units accessible to activation and frequency control. Elderly subjects also have difficulty in the activation of minimal contraction and in the maintenance of firing but to a significantly lesser degree than do parkinsonian patients. In this respect, the elderly patient and the parkinsonian patient are qualitatively similar.
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http://dx.doi.org/10.1212/wnl.25.9.866 | DOI Listing |
J Appl Physiol (1985)
January 2025
Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland.
Disruption of the blood supply to a limb in conjunction with active movement boosts muscle growth, aids in rehabilitation, and allows controlled exploration of the sensorimotor system. Yet, the underlying neuromechanical changes have not been observed in great detail. This study aims to report the acute neuromuscular effects of temporary blood flow restriction (BFR) through behavioral changes at the level of motor units (MUs) using high-density surface electromyography on the abductor digiti minimi muscle during 20 trapezoidal and sinusoidal isometric force tracking tasks (5 pre-BFR, 5 during BFR, and 10 post-BFR).
View Article and Find Full Text PDFJ Neurol
January 2025
Western Institute of Neuroscience, Western University, London, Canada.
Background: Repeat neurological assessment is standard in cases of severe acute brain injury. However, conventional measures rely on overt behavior. Unfortunately, behavioral responses may be difficult or impossible for some patients.
View Article and Find Full Text PDFCurr Res Physiol
December 2024
Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
Aging is accompanied by a decline in muscle mass, strength, and physical function, a condition known as sarcopenia. Muscle disuse attributed to decreased physical activity, hospitalization, or illness (e.g.
View Article and Find Full Text PDFBMJ Open
December 2024
Clinical Sciences, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.
Introduction: Infants born very preterm (VPT, <32 weeks' gestation) are at increased risk for neurodevelopmental impairments including motor, cognitive and behavioural delay. Parents of infants born VPT also have poorer mental health outcomes compared with parents of infants born at term.We have developed an intervention programme called TEDI-Prem (Telehealth for Early Developmental Intervention in babies born very preterm) based on previous research.
View Article and Find Full Text PDFCogn Neurodyn
December 2025
School of Systems Science, Beijing Normal University, Beijing, 100875 China.
Hippocampus in the mammalian brain supports navigation by building a cognitive map of the environment. However, only a few studies have investigated cognitive maps in large-scale arenas. To reveal the computational mechanisms underlying the formation of cognitive maps in large-scale environments, we propose a neural network model of the entorhinal-hippocampal neural circuit that integrates both spatial and non-spatial information.
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