Strength-duration properties and excitability of motor and sensory axons across different target thresholds
| العنوان: | Strength-duration properties and excitability of motor and sensory axons across different target thresholds |
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| المؤلفون: | Yoshimitsu Shimatani, Cindy Shin-Yi Lin, José Manuel Matamala, Matthew C. Kiernan |
| المصدر: | Journal of Neurophysiology. |
| بيانات النشر: | American Physiological Society, 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Physiology, General Neuroscience |
| الوصف: | The present series of studies aimed to investigate the biophysical basis underlying differences in behaviour between motor and sensory axons at different target response levels. In 24 healthy individuals, axonal excitability protocols measured strength-duration properties and latent addition across several axonal populations, with target amplitudes set at 10%, 20%, 40%, 60%. Strength-duration time constants (SDTCs) were typically longer at lower target levels for both motor and sensory axons. Threshold change at 0.2 ms during assessment of latent addition, representing a persistent Na+ current (Nap), was higher in sensory axons. Passive membrane properties were not different across target levels. Significant relationships were evident between the threshold change at 0.2 ms and SDTC across all target levels for motor and sensory axons. These differences were explored using mathematical modelling of excitability data. With decreasing target size, as the internodal leak conductance increased in sensory axons, the Barrett-Barrett conductance decreased, while the hyperpolarization-activated cation current ( Ih) channels became more depolarized. A similar pattern was observed in motor axons. As such, it was concluded that Nap was not responsible for the differences observed in SDTC between different target levels, although within specific target levels, Nap changes contributed to the variability of SDTC. This study provides a comprehensive assessment of Nap current, SDTC, and outlines key factors operating at different target levels in motor and sensory axons. Findings from the present study may point to the contributing factors of symptom development in human neuropathy. |
| تدمد: | 1522-1598 0022-3077 |
| DOI: | 10.1152/jn.00456.2022 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::e4c5102e2ca2b9de3d952cfbb2aa33be https://doi.org/10.1152/jn.00456.2022 |
| رقم الانضمام: | edsair.doi...........e4c5102e2ca2b9de3d952cfbb2aa33be |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15221598 00223077 |
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| DOI: | 10.1152/jn.00456.2022 |