Metcalfe B W, Chew D J, Clarke C T, Donaldson N de N, Taylor J T
Department of Electronic and Electrical Engineering, University of Bath, Bath, UK.
John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK.
J Neurosci Methods. 2015 Aug 15;251:47-55. doi: 10.1016/j.jneumeth.2015.05.003. Epub 2015 May 14.
This paper describes a series of experiments designed to verify a new method of electroneurogram (ENG) recording that enables the rate of neural firing within prescribed bands of propagation velocity to be determined in real time. Velocity selective recording (VSR) has been proposed as a solution to the problem of increasing the information available from an implantable neural interface (typically with electrodes in circumferential nerve cuffs) and has been successful in transforming compound action potentials into the velocity domain.
The new method extends VSR to naturally-evoked (physiological) ENG in which the rate of neural firing at particular velocities is required in addition to a knowledge of the velocities present in the recording.
The experiments, carried out in rats required individual spikes to be distinct and non-overlapping, which could be achieved by a microchannel or small-bore cuff. In these experiments, strands of rat nerve were laid on ten hook electrodes in oil to demonstrate the principle.
The new method generates a detailed overview of the firing rates of neurons based on their conduction velocity and direction of propagation. In addition it allows real time working in contrast to existing spike sorting methods using statistical pattern processing techniques.
Results show that by isolating neural activity based purely on conduction velocity it was possible to determine the onset of direct cutaneous stimulation of the L5 dermatome.
本文描述了一系列实验，旨在验证一种新的神经电图（ENG）记录方法，该方法能够实时确定规定传播速度范围内的神经放电速率。速度选择性记录（VSR）已被提出作为解决从可植入神经接口（通常是在圆周神经袖带中使用电极）获取更多信息这一问题的方法，并且已成功地将复合动作电位转换到速度域。
该新方法将VSR扩展到自然诱发的（生理的）ENG，其中除了要知道记录中存在的速度外，还需要特定速度下的神经放电速率。
在大鼠身上进行的实验要求单个尖峰清晰且不重叠，这可以通过微通道或小口径袖带来实现。在这些实验中，将大鼠神经束放置在油中的十个钩状电极上以演示该原理。
新方法基于神经元的传导速度和传播方向生成了神经元放电速率的详细概述。此外，与使用统计模式处理技术的现有尖峰分类方法相比，它允许实时操作。
结果表明，通过仅基于传导速度分离神经活动，可以确定L5皮节直接皮肤刺激的起始。
