Selective microstimulation of central nervous system neurons
Selective microstimulation of central nervous system neurons
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DOI：
10.1114/1.262
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发表时间：
2000-03-01
影响因子：
3.8
通讯作者：
Grill, WM
中科院分区：
文献类型：
--
作者：
McIntyre, CC;Grill, WM
本研究的目的是确定可有效选择性刺激中枢神经系统 (CNS) 内目标神经元群的刺激参数和电极几何形状。神经元电缆模型包括轴突、初始节段、胞体和分支树突树，其几何形状和膜动力学源自哺乳动物运动神经元，用于研究细胞外电极的激发。这些模型再现了各种实验记录的激励模式，包括电流-距离和强度-持续时间关系。使用随机定位在细胞外电极周围的五十个细胞和五十个通道纤维的群体来进行不同刺激范例的评估。单相阴极或阳极刺激分别能够选择性刺激纤维相对于细胞或细胞相对于纤维。然而，当加入对称电荷平衡刺激相时，选择性大大降低。第一阳极、第二阴极不对称双相刺激能够选择性刺激纤维，而第一阴极、第二阳极不对称双相刺激能够选择性刺激细胞。这些新颖的波形提供了增强的选择性，同时保持电荷平衡，以最大限度地减少电极腐蚀和组织损伤的风险。此外，本研究开发的模型可以预测电极几何形状和刺激参数对特定神经元群体选择性激活的有效性，反过来又代表了设计中枢神经系统神经假体装置中使用的电极和刺激波形的有用工具。 (C) 2000 年生物医学工程学会。 [S0090-6964(00)00X03-1]。
The goal of this study was to identify stimulus parameters and electrode geometries that were effective in selectively stimulating targeted neuronal populations within the central nervous system (CNS). Cable models of neurons that included an axon, initial segment, soma, and branching dendritic tree, with geometries and membrane dynamics derived from mammalian motoneurons, were used to study excitation with extracellular electrodes. The models reproduced a wide range of experimentally documented excitation patterns including current-distance and strength-duration relationships. Evaluation of different stimulus paradigms was performed using populations of fifty cells and fifty fibers of passage randomly positioned about an extracellular electrode(s). Monophasic cathodic or anodic stimuli enabled selective stimulation of fibers over cells or cells over fibers, respectively. However, when a symmetrical charge-balancing stimulus phase was incorporated, selectivity was greatly diminished. An anodic first, cathodic second asymmetrical biphasic stimulus enabled selective stimulation of fibers, while a cathodic first, anodic second asymmetrical biphasic stimulus enabled selective stimulation of cells. These novel waveforms provided enhanced selectivity while preserving charge balancing as is required to minimize the risk of electrode corrosion and tissue injury. Furthermore, the models developed in this study can predict the effectiveness of electrode geometries and stimulus parameters for selective activation of specific neuronal populations, and in turn represent useful tools for the design of electrodes and stimulus waveforms for use in CNS neural prosthetic devices. (C) 2000 Biomedical Engineering Society. [S0090-6964(00)00X03-1].