Supraspinal effects on the fractal correlation in human H-reflex
Supraspinal effects on the fractal correlation in human H-reflex
复制标题
脊髓上对人类 H 反射分形相关性的影响
DOI：
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复制
发表时间：
1996
影响因子：
2
通讯作者：
Y. Yamamoto
中科院分区：
文献类型：
--
作者：
D. Nozaki;K. Nakazawa;Y. Yamamoto
摘要在我们之前的研究中，
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比目鱼肌H反射波幅变异性表现为频谱指数β显着大于零的功率谱。这一结果表明，H反射的变异性具有时间相关性，这是由于其具有分形性。此外，我们还认为这种分维特征是在脊髓水平上产生的。本研究的目的是探讨H反射变异性的分形性是否受失去脊髓上输入的影响。6名健康正常人和7名脊髓损伤患者参与本研究。每例L、S双腿同时诱发比目鱼肌H反射(刺激强度：运动阈值)，记录1050个连续的H反射波幅。对每条腿诱发的H反射序列进行“粗粒化频谱分析”，计算频谱指数β。用β值来评价时间相关性(分形相关)的程度。交叉频谱分析用于评估从双腿诱发的H反射序列之间的同步度。正常人的β(左腿0.84±0.33，右腿0.88±0.34)显著高于患者(0.31±0.18，0.32±0.14)(P<；0.001)，提示正常人的H反射序列比患者更具时间相关性。在小于0.20赫兹的频率范围内，正常人双腿的相干性(0.41±0.14)高于患者(0.20±0.12)(P<；0.005)。在此频率范围内，正常受试者的相位几乎为0rad，表明两条腿的H反射变异是同步的。这些结果表明：(1)正常人H-反射序列中观察到的较强的分形相关性与棘上输入有关；(2)这种棘上输入对双腿比目鱼肌的反射弧有同等的影响。
AbstractIn our previous study,
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-type power spectrum with the spectral exponent β significantly greater than zero was found in the variability of soleus H-reflex amplitudes. This result indicated that the H-reflex variability was time-correlated owing to fractal characteristics. Furthermore, it was also suggested that the fractal characteristics were generated at the spinal level. The purpose of the present study was to investigate whether the fractal nature of the H-reflex variability was influenced by the loss of supraspinal input. Six healthy normal subjects and seven patients with spinal cord injury participated in this study. Soleus H-reflexes were evoked every l s from both legs simultaneously (stimulation intensity: motor threshold) and 1050 successive amplitudes of the H-reflex were recorded. The H-reflex sequence evoked from each leg was analyzed by “coarse graining spectral analysis” to calculate the spectral exponent β. The value of β was used to evaluate the level of time-correlation (fractal correlation). Cross-spectral analysis was used to evaluate the degree of synchronization between the H-reflex sequences evoked from both legs. The β values for normal subjects (0.84±0.33, left leg; 0.88±0.34, right leg) were significantly greater (P<0.001) than those for patients (0.31±0.18, left leg; 0.32±0.14, right leg), suggesting that the H-reflex sequences for normal subjects were more time-correlated than for patients. In the frequency range less than 0.2 Hz, the coherence of both legs was high (0.41±0.14) for normal subjects as compared to 0.20±0.12 for patients (P<0.005). In this frequency range, the phase was almost 0 rad for normal subjects, indicating that the H-reflex variabilities of both legs were synchronized. These results suggested that (1) the strong fractal correlation observed in the H-reflex sequences for normal subjects was associated with supraspinal input, and (2) such supraspinal input had equal influence on the reflex arcs of the soleus of both legs.
DOI：
10.1016/0168-5597(93)90131-8
发表时间：
1993-06-01
期刊：
ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY
影响因子：
--
作者：
CALANCIE, B;BROTON, JG;AYYAR, DR
通讯作者：
AYYAR, DR
猫腰部运动神经元单突触反射通路的兴奋性波动。
影响因子：
2.5
作者：
Gossard,JP;Floeter,MK;Kawai,Y;Burke,RE;Chang,T;Schiff,SJ
通讯作者：
Schiff,SJ