Persistent inward currents in tibialis anterior motoneurons can be reliably estimated within the same session

Authors

Thomas Lapole
Ricardo N.O. Mesquita, Edith Cowan UniversityFollow
Stéphane Baudry
Robin Souron
Eleanor K. O'Brien, Edith Cowan UniversityFollow
Callum G. Brownstein
Vianney Rozand

Document Type

Journal Article

Publication Title

Journal of Electromyography and Kinesiology

Volume

78

Publisher

Elsevier

School

Centre for Precision Health / School of Medical and Health Sciences

RAS ID

70383

Funders

Jean Monnet University

Comments

Lapole, T., Mesquita, R. N., Baudry, S., Souron, R., O’Brien, E. K., Brownstein, C. G., & Rozand, V. (2024). Persistent inward currents in tibialis anterior motoneurons can be reliably estimated within the same session. Journal of Electromyography and Kinesiology, 102911. https://doi.org/10.1016/j.jelekin.2024.102911

Abstract

The response of spinal motoneurons to synaptic input greatly depends on the activation of persistent inward currents (PICs), the contribution of which can be estimated through the paired motor unit technique. Yet, the intra-session test–retest reliability of this measurement remains to be fully established. Twenty males performed isometric triangular dorsiflexion contractions to 20 and 50 % of maximal torque at baseline and after a 15-min resting period. High-density electromyographic signals (HD-EMG) of the tibialis anterior were recorded with a 64-electrode matrix. HD-EMG signals were decomposed, and motor units tracked across time points to estimate the contribution of PICs to motoneuron firing through quantification of motor unit recruitment-derecruitment hysteresis (ΔF). A good intraclass correlation coefficient (ICC = 0.75 [0.63, 0.83]) and a large repeated measures correlation coefficient (rrm = 0.65 [0.49, 0.77]; p < 0.001) were found between ΔF values obtained at both time points for 20 % MVC ramps. For 50 % MVC ramps, a good ICC (0.77 [0.65, 0.85]) and a very large repeated measures correlation coefficient (rrm = 0.73 [0.63, 0.80]; p < 0.001) were observed. Our data suggest that ΔF scores can be reliably investigated in tibialis anterior motor units during both low- and moderate-intensity contractions within a single experimental session.

DOI

10.1016/j.jelekin.2024.102911

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