Micro-electrode arrays for multi-channel motor unit EMG recording

Author(s):  
Shota Yamagiwa ◽  
Hirohito Sawahata ◽  
Makoto Ishida ◽  
Takeshi Kawano
2012 ◽  
Vol 207 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Alessandro Maccione ◽  
Matteo Garofalo ◽  
Thierry Nieus ◽  
Mariateresa Tedesco ◽  
Luca Berdondini ◽  
...  

1990 ◽  
Vol 68 (5) ◽  
pp. 1917-1926 ◽  
Author(s):  
G. C. Sieck ◽  
M. Fournier

Fatigue-related changes in the waveform and root-mean-square (rms) values of evoked motor unit electromyographic (EMG) responses were studied in the right sternocostal region of the cat diaphragm. Motor units were isolated by microdissection and stimulation of C5 ventral root filaments and then classified as fast-twitch fatigable (FF), fast-twitch fatigue intermediate (FInt), fast-twitch fatigue resistant (FR), or slow-twitch (S) based on standard physiological criteria. The evoked EMG responses of S and FR units showed very little change during the fatigue test. The evoked EMG waveform and rms values of FF and FInt units displayed variable changes during the fatigue test. When changes were observed, they typically included a prolongation of the EMG waveform, a decrease in peak amplitude, and a decrease in rms value. The changes in EMG amplitude and rms values were not correlated. In more fatigable units, the decrease in force during the fatigue test generally exceeded the decrease in EMG rms values. Changes in the evoked force and EMG responses of multiple units innervated by C5 or C6 ventral roots were also examined during the fatigue test. The decrease in diaphragm force during the fatigue test closely matched the force decline predicted by the proportionate contribution of different motor unit types. However, the observed reduction in diaphragm EMG rms values during the fatigue test exceeded that predicted based on the aggregate contribution of different motor unit types. It was concluded that changes in EMG do not reflect the extent of diaphragm fatigue.


2006 ◽  
Vol 95 (3) ◽  
pp. 1518-1526 ◽  
Author(s):  
C. K. Thomas ◽  
R. S. Johansson ◽  
B. Bigland-Ritchie

Few studies have analyzed activity-induced changes in EMG activity in individual human motor units. We studied the changes in human thenar motor unit EMG that accompany the potentiation of twitch force and fatigue of tetanic force. Single motor unit EMG and force were recorded in healthy subjects in response to selective stimulation of their motor axons within the median nerve just above the elbow. Twitches were recorded before and after a series of pulse trains delivered at frequencies that varied between 5 and 100 Hz. This stimulation induced significant increases in EMG amplitude, duration, and area. However, in relative terms, all of these EMG changes were substantially smaller than the potentiation of twitch force. Another 2 min of stimulation (13 pulses at 40 Hz each second) induced additional potentiation of EMG amplitude, duration, and area, but the tetanic force from every unit declined. Thus activity-induced changes in human thenar motor unit EMG do not indicate the alterations in force or vice versa. These data suggest that different processes underlie the changes in EMG and force that occur during human thenar motor unit activity.


2016 ◽  
Vol 214 (2) ◽  
pp. 1532347 ◽  
Author(s):  
Farnoosh Vahidpour ◽  
Lowry Curley ◽  
István Biró ◽  
Matthew McDonald ◽  
Dieter Croux ◽  
...  

2018 ◽  
Vol 4 (1) ◽  
pp. 469-472 ◽  
Author(s):  
Michael Schweigmann ◽  
Klaus Peter Koch ◽  
Fabian Auler ◽  
Frank Kirchhoff

AbstractThe quality of bioelectrical signals is essential for functional evaluation of cellular circuits. The electrical activity recorded from the cortical brain surface represents the average of many individual synaptic processes. By downsizing micro-electrode arrays, the spatial resolution of electrocortico-grams (ECoGs) can be increased. But, upon increasing electrode impedance, recorded noise from the electrode-tissue interface and the surroundings will become more prominent. Frequently, signal interpretation is improved by post-processing using filtering or pattern recognition. For a variety of applications, wavelet denoising has become an accepted tool. Here, we present how wavelet denoising affects the signal-to-noise ratio of ECoGs. The recording qualities from awake and anesthetized mice was artificially reduced by adding two noise models prior to filtering. Raw and filtered signals were compared by calculating the linear correlation coefficient.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 830
Author(s):  
Wataru Minoshima ◽  
Kyoko Masui ◽  
Tomomi Tani ◽  
Yasunori Nawa ◽  
Satoshi Fujita ◽  
...  

The excitatory synaptic transmission is mediated by glutamate (GLU) in neuronal networks of the mammalian brain. In addition to the synaptic GLU, extra-synaptic GLU is known to modulate the neuronal activity. In neuronal networks, GLU uptake is an important role of neurons and glial cells for lowering the concentration of extracellular GLU and to avoid the excitotoxicity. Monitoring the spatial distribution of intracellular GLU is important to study the uptake of GLU, but the approach has been hampered by the absence of appropriate GLU analogs that report the localization of GLU. Deuterium-labeled glutamate (GLU-D) is a promising tracer for monitoring the intracellular concentration of glutamate, but physiological properties of GLU-D have not been studied. Here we study the effects of extracellular GLU-D for the neuronal activity by using primary cultured rat hippocampal neurons that form neuronal networks on microelectrode array. The frequency of firing in the spontaneous activity of neurons increased with the increasing concentration of extracellular GLU-D. The frequency of synchronized burst activity in neurons increased similarly as we observed in the spontaneous activity. These changes of the neuronal activity with extracellular GLU-D were suppressed by antagonists of glutamate receptors. These results suggest that GLU-D can be used as an analog of GLU with equivalent effects for facilitating the neuronal activity. We anticipate GLU-D developing as a promising analog of GLU for studying the dynamics of glutamate during neuronal activity.


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