Changes in electrophysiological properties of rat motoneurons evoked by A5-week sterngth training

• Autorzy: Mrowczynski W. , Lochynski D. , Kaczmarek D. , Baczyk M. , Celichowski J. , Krutki P.
• Języki publikacji: EN

Abstrakty

EN

BACKGROUND AND AIMS: Different forms of chronic physical activity evoke adaptive changes in the neuromuscular system. Long-lasting strength training, with repeated short-term and highintensity exercises, is responsible for an increase of muscle mass and generation of larger forces. However, adaptations in properties of motoneurons innervating muscles subjected to such training have been unknown so far. The aim of this study in the rat was to determine whether the strength training induces changes of passive and threshold membrane properties, and rhythmic firing of motoneurons. METHODS: The study was performed on eight adult Wistar rats, randomly assigned to the training or the control groups. Animals from the training group were nutritionally conditioned in order to make weightlifting put on their shoulders in a special apparatus with progressively increasing load, for 5 weeks. Acute electrophysiological experiments were performed on deeply anesthetized animals from both groups, using microelectrode intracellular recordings from motoneurons innervating hind limb muscles. RESULTS: It was demonstrated that 5-week strength training evoked adaptive changes in both fast and slow types of motoneurons: a shortening of the rise time of action potentials, an increase of the maximum frequencies of rhythmic firing, and an increase in the slope of the frequency-current relationship. CONCLUSIONS: Obtained data suggest higher susceptibility of motoneurons to an increased or decreased intensity of stimulation. Moreover, a decrease in rheobase currents, and a decrease in the minimum currents required to evoke rhythmic firing was observed in fast-type motoneurons only, suggesting their higher excitability. Supported by the National Science Center grant No. 2013/11/B/ NZ7/01518.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S71-S72

Twórcy

autor

Mrowczynski W.

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

autor

Lochynski D.

• Department of Motor Rehabilitation, Department of Neurobiology, University School of Physical Education, Poznan, Poland

autor

Kaczmarek D.

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

autor

Baczyk M.

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

autor

Celichowski J.

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

autor

Krutki P.

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