Summation of NMG signals during co-activity of two isolated motor units in medical gastrocnemius muscle of the rat

• Autorzy: Kaczmarek P. , Celichowski J. , Drzymala-Celichowska H. , Kasinski A.
• Języki publikacji: EN

Abstrakty

EN

The MMG signal generated in contracting pennate muscle is due to a transversal displacement of the its surface. It was shown on the base of in vivo experiments and a computer model that the MMG signal recorded during an isolated motor unit (MU) contraction is dependent on the stimulation frequency, the position of the laser distance sensor (LDS) and MU architecture. The three different profi les of the MMG can be observed. The fi rst type denoted as N (negative) is observed for the LDS located over the proximal connection of the MU (the distance from the muscle surface decreases with contraction force increase). In class P (positive) the relationship is opposite to N and the LDS is located over the area between distal connection of the MU and tendon of insertion. Finally, for the third class denoted as M (mixed) the MMG is initially positive, and when the contraction force exceed a certain level it starts to decrease and becomes negative. The process of the MMG summation during two MUs contraction was also investigated. It was observed that for the MUs with MMG-N or MMG-M profi le the MMG summation was quasi linear. In case of twitch and unfused contractions it was equal the algebraic sum of the individual MMGs. In case of the fused contraction the resulted MMG was slightly lesser than the algebraic sum. In opposition, the contraction of two MUs MMG-P induced the MMG signal lesser than the algebraic sum and the resulted signal was nearly equal the MMG presented by stronger MU.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2009
• Tom: 69
• Numer: 3
• Opis fizyczny: p.329

Twórcy

autor

Kaczmarek P.

• Institute of Control and Information Engeenering, Poznan University of Technology, Poznan, Poland

autor

Celichowski J.

• Department of Neurobiology, University School of Physical Education in Poznan, Poznan, Poland

autor

Drzymala-Celichowska H.

• Department of Neurobiology, University School of Physical Education in Poznan, Poznan, Poland

autor

Kasinski A.

• Institute of Control and Information Engeenering, Poznan University of Technology, Poznan, Poland