Minimal tonic firing rates of human lateral pterygoid single motor units
| Autor: | K. Wanigaratne, Terry Whittle, Greg M. Murray, I. Phanachet |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Adult
Male Movement Biology Lateral pterygoid muscle stomatognathic system Physiology (medical) Humans Electrodes Motor Neurons Muscle Cells Continuous Firing Jaw movement Motor control Body movement Pterygoid Muscles Anatomy Sensory Systems Motor unit Electrophysiology Incisor Neurology Jaw Tonic firing Female Neurology (clinical) |
| Zdroj: | Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 115(1) |
| ISSN: | 1388-2457 |
| Popis: | Objective : The minimal tonic firing rates (the lowest firing rates at which motor units fire regularly; MTFR) of single motor units (SMUs) within the lateral pterygoid muscle have not been widely investigated. The aims of this study were (a) to identify MTFR of SMUs within the inferior head (IHLP) and superior head (SHLP) of the lateral pterygoid muscle during horizontal jaw movements, and (b) to determine whether these MTFR vary with movement direction. Methods : Twenty subjects moved the jaw to maintain SMU firing at the lowest continuous firing rate. SMU activity was recorded from computer-tomography-verified sites within the IHLP or SHLP. Results : In the IHLP, the mean (±SD) MTFR for contralateral movement (15.6±2.3 imp/s; n =22 SMUs) were not significantly different from those during protrusion (16.3±3.4 imp/s; n =19). In the SHLP, the mean (±SD) MTFR for contralateral, ipsilateral movement, and protrusion were 14.7±2.5 imp/s ( n =10), 13.2±2.1 imp/s ( n =8), and 16.2±3.7 imp/s ( n =2), respectively. Conclusions : Lateral pterygoid SMUs have greater MTFR than previously reported in the masseter and IHLP, namely 5–8 and 8–10 imp/s, respectively. The MTFR did not vary with the task within each muscle head. Significance : Some physiological properties of lateral pterygoid SMUs may be different from those in other jaw muscles. |
| Databáze: | OpenAIRE |
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