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Effects Of Jaw Clenching And Mental Stress On Persistent Inward Currents Estimated By Two Different Methods, Ricardo N. O. Mesquita, Janet L. Taylor, Gabriel S. Trajano, Aleš Holobar, Basílio A. M. Gonçalves, Anthony J. Blazevich

Research outputs 2022 to 2026

Spinal motoneuron firing depends greatly on persistent inward currents (PICs), which in turn are facilitated by the neuromodulators serotonin and noradrenaline. The aim of this study was to determine whether jaw clenching (JC) and mental stress (MS), which may increase neuromodulator release, facilitate PICs in human motoneurons. The paired motor unit (MU) technique was used to estimate PIC contribution to motoneuron firing. Surface electromyograms were collected using a 32-channel matrix on gastrocnemius medialis (GM) during voluntary, ramp, plantar flexor contractions. MU discharges were identified, and delta frequency ( F), a measure of recruitment–derecruitment hysteresis, was calculated. Additionally, another technique was …