Human motor unit discharge patterns reveal differences in neuromodulatory and inhibitory drive to motoneurons across contraction levels
Jakob Škarabot, James A. Beauchamp, Gregory E. P. Pearcey
Abstract
How the structure of motor commands is modified to scale motor output is largely speculative despite its critical role in the neural control of movement. Here, we demonstrate that human motor unit discharge patterns become more linear and exhibit greater discharge rate hysteresis with greater contraction force. These experimentally observed patterns can only be replicated in silico with biophysical spinal motoneuron models by increasing neuromodulation and a shift from tonic to push-pull excitation-inhibition synaptic control.
Topics & Concepts
Inhibitory postsynaptic potentialMotor unitContraction (grammar)NeuroscienceChemistryMuscle contractionMotor unit recruitmentNeuromodulationIonotropic effectMotor neuronElectrophysiologyMotor controlBiophysicsMembrane potentialMetabotropic receptorSilent periodMuscle activation and electromyography studiesNeuroscience and Neural EngineeringMotor Control and Adaptation