Vogelstein R Jacob, Etienne-Cummings Ralph, Thakor Nitish V, Cohen Avis H
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA.
IEEE Trans Neural Syst Rehabil Eng. 2006 Sep;14(3):257-65. doi: 10.1109/TNSRE.2006.881586.
This paper examines how electrical stimulation of the spinal cord can modulate the output of the central pattern generator (CPG) for locomotion. Application of discrete current pulses to a single spinal segment was shown to affect multiple parameters of an ongoing locomotor pattern in an in vitro spinal cord. For any given stimulus, the effects on frequency, duration, and symmetry of locomotor output were strongly dependent on the phase at which stimulation was applied within the CPG cycle. Additionally, most stimuli had an immediate impact and evinced no effects on subsequent cycles. The most dramatic changes were seen when stimulation was applied during motor bursting: stimuli applied to the ipsilateral spinal hemicord increased the burst length, while stimuli applied to the contralateral spinal hemicord decreased the burst length. Smaller changes were observed when stimulating during delays between motor bursts. Thus, phasic stimulation was shown to influence the behavior of the CPG and spinal locomotion circuits on a cycle-by-cycle basis. This work represents the first step toward our ultimate goal of developing a neuroprosthetic device to restore locomotion after a severe spinal cord injury.
本文研究了脊髓电刺激如何调节用于运动的中枢模式发生器（CPG）的输出。在体外脊髓中，向单个脊髓节段施加离散电流脉冲被证明会影响正在进行的运动模式的多个参数。对于任何给定的刺激，对运动输出的频率、持续时间和对称性的影响在很大程度上取决于在CPG周期内施加刺激的相位。此外，大多数刺激具有即时影响，并且对后续周期没有影响。当在运动爆发期间施加刺激时，会出现最显著的变化：施加到同侧脊髓半侧的刺激会增加爆发长度，而施加到对侧脊髓半侧的刺激会减少爆发长度。在运动爆发之间的延迟期间进行刺激时，观察到的变化较小。因此，已证明相位刺激会逐周期影响CPG和脊髓运动回路的行为。这项工作是我们开发神经假体装置以在严重脊髓损伤后恢复运动这一最终目标的第一步。
