Microstimulation of primary afferent neurons in the L7 dorsal root ganglia using multielectrode arrays in anesthetized cats: thresholds and recruitment properties
Microstimulation of primary afferent neurons in the L7 dorsal root ganglia using multielectrode arrays in anesthetized cats: thresholds and recruitment properties
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DOI：
10.1088/1741-2560/6/5/055009
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发表时间：
2009-10-01
影响因子：
4
通讯作者：
Weber, D. J.
中科院分区：
文献类型：
--
作者：
Gaunt, R. A.;Hokanson, J. A.;Weber, D. J.
Current research in motor neural prosthetics has focused primarily on issues related to the extraction of motor command signals from the brain (e. g. brain-machine interfaces) to direct the motion of prosthetic limbs. Patients using these types of systems could benefit from a somatosensory neural interface that conveys natural tactile and kinesthetic sensations for the prosthesis.背根神经节（DRG）内的电微刺激已被提议作为实现这一目标的一种方法，但人们对电微刺激在激活该结构中的神经纤维时的募集特性知之甚少。 Current-controlled microstimulation pulses in the range of 1-15 mu A (200 mu s, leading cathodic pulse) were delivered to the L7 DRG in four anesthetized cats using penetrating microelectrode arrays. Evoked responses and their corresponding conduction velocities (CVs) were measured in the sciatic nerve with a 5-pole nerve cuff electrode arranged as two adjacent tripoles. It was found that in 76% of the 69 electrodes tested, the stimulus threshold was less than or equal to 3 mu A, with the lowest recorded threshold being 1.1 mu A. The CVs of afferents recruited at threshold had a bimodal distribution with peaks at 70 m s(-1) and 85 m s(-1). In 53% of cases, the CV of the response at threshold was slower (i.e. smaller diameter fiber) than the CVs of responses observed at increasing stimulation amplitudes. In summary, we found that microstimulation applied through penetrating microelectrodes in the DRG provides selective recruitment of afferent fibers from a range of sensory modalities (as identified by CVs) at very low stimulation intensities.我们的结论是，DRG 可能是一个有吸引力的位置，可以将替代体感反馈引入神经系统。
Current research in motor neural prosthetics has focused primarily on issues related to the extraction of motor command signals from the brain (e. g. brain-machine interfaces) to direct the motion of prosthetic limbs. Patients using these types of systems could benefit from a somatosensory neural interface that conveys natural tactile and kinesthetic sensations for the prosthesis. Electrical microstimulation within the dorsal root ganglia (DRG) has been proposed as one method to accomplish this, yet little is known about the recruitment properties of electrical microstimulation in activating nerve fibers in this structure. Current-controlled microstimulation pulses in the range of 1-15 mu A (200 mu s, leading cathodic pulse) were delivered to the L7 DRG in four anesthetized cats using penetrating microelectrode arrays. Evoked responses and their corresponding conduction velocities (CVs) were measured in the sciatic nerve with a 5-pole nerve cuff electrode arranged as two adjacent tripoles. It was found that in 76% of the 69 electrodes tested, the stimulus threshold was less than or equal to 3 mu A, with the lowest recorded threshold being 1.1 mu A. The CVs of afferents recruited at threshold had a bimodal distribution with peaks at 70 m s(-1) and 85 m s(-1). In 53% of cases, the CV of the response at threshold was slower (i.e. smaller diameter fiber) than the CVs of responses observed at increasing stimulation amplitudes. In summary, we found that microstimulation applied through penetrating microelectrodes in the DRG provides selective recruitment of afferent fibers from a range of sensory modalities (as identified by CVs) at very low stimulation intensities. We conclude that the DRG may serve as an attractive location from which to introduce surrogate somatosensory feedback into the nervous system.