Long-lasting effects of trans-spinal direct current stimulation on motoneuron firing properties in rats

• Autorzy: Krutki P. , Drzymala-Celichowska H. , Mrowczynski W. , Baczyk M.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: Trans-spinal direct current stimulation (tsDCS) is a neuromodulative technique used to improve motor functions in neurological disorders and to facilitate sport performance. However, despite the broad application of spinal cord polarization, the physiological mechanisms behind the observed effects remain unclear. We have recently demonstrated that anodal or cathodal tsDCS can alter motoneuron membrane properties and firing characteristics during its application and beyond. AIM(S): The aim of this study was to determine whether these alterations persist over a longer period of time. METHOD(S): The study was performed on adult male Wistar rats under general anesthesia. Anodal or cathodal tsDCS (0.1 mA, 15 min) was applied through an electrode located on the lumbar vertebra above the recording site. The intracellular recordings from L4‑L5 spinal motoneurons were performed at various periods after the offset of polarization (up to 3 hours). The animals not subjected to tsDCS formed the control group. RESULTS: Anodal tsDCS evoked a significant decrease in the voltage threshold, the rheobase, the threshold for rhythmic steady-state firing, as well as, an increase in the steady‑state firing frequencies and the slope of the frequency‑current relationship. Some of these modulatory effects were observed up to 60 minutes after the offset of polarization. Cathodal tsDCS induced only modest changes in motoneuron threshold properties, which could be observed no longer than 30 minutes after the end of polarization. CONCLUSIONS: This study for the first time provides the direct evidence that tsDCS evokes long-term alterations in the threshold and rhythmic firing properties of spinal motoneurons. Modulatory effects of anodal polarization are stronger and last longer than those of cathodal tsDCS. We suppose that both autonomous cell mechanisms and synaptic effects contribute to the occurrence and long-term persistence of the indicated changes in motoneuron properties. FINANCIAL SUPPORT: Supported by the National Science Center grant No 2017/25/B/NZ7/00373.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2019
• Tom: 79
• Numer: Suppl.1
• Opis fizyczny: p.XLIX-L

Twórcy

autor

Krutki P.

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

autor

Drzymala-Celichowska H.

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

autor

Mrowczynski W.

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

autor

Baczyk M.

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