Sinusoidal mechanical responses from single motor units of rat medial gastrocnemius muscle

• Autorzy: Drzymala-Celichowska H. , Krysciak K. , Kaczmarek P. , Orizio C. , Krutki P. , Celichowski J.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: The relationship between the output force and motor command depends on the intrinsic RESULTS: The mathematical decomposition of unfused tetanic contractions of FF and FR MUs into twitch-shape responses to consecutive stimuli was conducted. The decomposition indicated substantial changes predominantly in force and additionally in time parameters of successive twitch‑like components, responsible for a sag profile in tetanic curve. Namely, initially the force increased and the highest force was observed in a response to the 2nd–3rd stimulus for FF units, while after the 3rd–7th stimulus for FR MUs and later decreased leading to the sag. In the second series of experiments, a repeatability of the sag in tetanic contractions of the same MU in a muscle with preserved blood circulation and under ischemic conditions was tested. Sag restitution was present in muscles with the circulation preserved but it was prevented by occlusion of blood vessels, indicating that sag depends on an availability of an energy source which can be restituted under aerobic conditions. CONCLUSIONS: The study indicated that sag profile of unfused tetanic contractions is predominantly an effect of early increase in amplitudes of several initial responses followed by a decrease in their amplitudes and that these changes are stronger and longer in time scale in FR than in FF MUs. The results concerning repeatability of the phenomenon suggest that most probable source of energy for initial force increase is phosphocreatine.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.82-83

Twórcy

autor

Drzymala-Celichowska H.

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

autor

Krysciak K.

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

autor

Kaczmarek P.

• Institute of Control and Information Engineering, Faculty of Electrical Engineering, Poznan University of Technology, Poznan, Poland

autor

Orizio C.

• Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy

autor

Krutki P.

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

autor

Celichowski J.

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