Effects of age on excitability properties in human motor axons
Effects of age on excitability properties in human motor axons
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DOI：
10.1016/j.clinph.2008.07.005
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发表时间：
2008-10-01
影响因子：
4.7
通讯作者：
Kuwabara, Satoshi
中科院分区：
文献类型：
--
作者：
Bae, Jong Seok;Sawai, Setsu;Kuwabara, Satoshi
目的：阈值跟踪技术是一种无创评估人体轴突膜生物物理特性的新方法。本研究的目的是评估年龄和性别对人类运动轴突兴奋性特性的影响。方法：采用计算机阈值跟踪法测量93例正常人（男性50例，年龄20 ~ 86岁）运动轴突中位兴奋性指数。结果：回归分析显示，年龄越大，强度-持续时间常数越长（p = 0.03），去极化阈值电张力阈值变化越小（p = 0.02），超正态性越小（p = 0.01），超极化电流阈值关系斜率越陡（p < 0.001）。在流变基数、阈值电张力、异常、晚期亚正常和电流阈斜率方面存在轻微的性别差异，尽管它们仅在年龄亚组中具有显著性
Objective: The threshold tracking technique is a new approach to non-invasively assess biophysical properties of axonal membrane in human subjects. The aim of this study was to evaluate the effects of age and gender on excitability properties of human motor axons.Methods: Computerized threshold tracking was used to measure multiple excitability indices in median motor axons of 93 normal subjects (50 men; age, 20-86 years).Results: Regression analyses showed that the higher age was associated with longer strength-duration time constant (p = 0.03), smaller threshold changes in depolarizing threshold electrotonus (p = 0.02), smaller super-normality (p = 0.01), and steeper slope of the current-threshold relationship for hyperpolarizing currents (p < 0.001). There were slight sex differences in rheobase, threshold electrotonus, supernormality, late subnormality, and current-threshold slope, though they were significant only in the subgroup with age