In motor control studies, the F-wave (a recurrent discharge evoked by an axonal antidromic volley) widely used for obtaining information on motoneuron pool behavior. However, such F-wave using is a matter of discussion and still has been not validated experimentally. The aim of the present study was investigation of F-wave properties of single firing motor units (MUs) in healthy humans, the properties, which could give evidence for F-wave origin in motoneuron soma and, therefore, could be used for estimation of a relation between MU firing and motoneuron firing behavior. In total, 91 MUs in five muscles of six healthy subjects, during gentle voluntary contractions, were studied. Peri-stimulus time histograms of single MUs were plotted. None of them revealed statistically significant increasing in MU firing probability at the F-wave latency. Analysis of relationships between characteristics of motoneuron firing behavior (mean firing frequency and target interspike interval duration) and properties of F-waves showed their independence. At the same time, it was found that F-waves were recorded in MUs, whose axons possessed the marked supernormal period in excitability recovery cycle after a discharge. Thus, the present results are in contrast to that which should be expected if the F-wave originated in the motoneuronal soma and could provide evidence for motoneuron firing behavior.
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http://dx.doi.org/10.1016/j.jelekin.2022.102641 | DOI Listing |
The opioid epidemic is a pervasive health issue and continues to have a drastic impact on the United States. This is primarily because opioids cause respiratory suppression and the leading cause of death in opioid overdose is respiratory failure ( , opioid-induced respiratory depression, OIRD). Opioid administration can affect the frequency and magnitude of inspiratory motor drive by activating µ-opioid receptors that are located throughout the respiratory control network in the brainstem.
View Article and Find Full Text PDFNeuroscience
January 2025
Department of Neurology, Binzhou Medical University Hospital, 256603 Binzhou, Shandong, PR China. Electronic address:
Astragaloside Ⅳ (AS-Ⅳ) improved the motor behavior of PD mouse but the alteration of imaging in the PD mice brain was unclear. PD models were established by unilateral injection of ROT into the substantia nigra pars compacta (SNc) of mice. AS-Ⅳ (4 mg/kg) was intraperitoneally injected once a day for 14 days.
View Article and Find Full Text PDFNeuroimage
January 2025
School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, Shandong, China. Electronic address:
The monosynaptic cortico-motoneuronal connections suggest the possibility of individual motor units (MUs) receiving independent commands from motor cortex. However, previous studies that used corticomuscular coherence (CMC) between electroencephalogram (EEG) signals and electromyogram (EMG) signals have not directly explored the corticospinal functionality at the single motoneuron level. The objective of this study is to find out whether synchronous activities exist between the motor cortex and individual MUs.
View Article and Find Full Text PDFCogn Neurodyn
December 2025
Exercise Physiology and Neurobiology Lab, College of Physical Education and Sports, Beijing Normal University, No. 19, Xinjiekou Street, Beijing, 100875 China.
Fatigue, a complex and multifaceted symptom, profoundly influences quality of life, particularly among individuals suffering from chronic medical conditions or neurological disorders. This symptom not only exacerbates existing conditions but also hinders daily functioning, thereby perpetuating a vicious cycle of worsening symptoms and reduced physical activity. Given the pivotal role of the motor cortex (M1) in coordinating and executing voluntary movements, understanding how the cortex regulates fatigue is crucial.
View Article and Find Full Text PDFFront Behav Neurosci
December 2024
Department of Biology, Miami University, Oxford, OH, United States.
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