Design of neural prosthetic system for lost sensory functions using microelectrode arrays

本研究的目的是建立设计准则，开发神经假体，恢复失去的感觉功能，由于感觉细胞或通路的障碍。研究成果总结如下。首先，我们开发了一种听觉脑干植入物（ABI）的实验动物模型，该模型直接刺激脑干中的耳蜗核，以恢复听觉神经被移除的耳聋患者的听力。该模型包括一个用于记录听觉皮层的表面微电极阵列和一个用于微刺激耳蜗核的棘波微电极阵列。第二，在大鼠ABI模型上，我们证实耳蜗核微刺激可以引起听皮层的时空神经活动，并且在纯音诱发的激活之后可以进行适当的刺激，这表明刺激可以引起音高和强度感觉，从而从实质上验证了听觉皮层的听觉活动的能力。 关于我们 第三，我们提出并验证了“多门控刺激”，它可以选择性地激活位于电极之间的神经。该技术广泛地用“阴极源电极”产生动作电位，同时用“阳极门电极”阻断不必要的传播，导致电极之间的选择性传播。我们通过神经方程的模拟和大鼠脊髓刺激的在体实验证明了这种方法的可行性。第四，我们的皮层听觉诱发电位（AEP）图显示，大鼠听皮层被划分为多个听觉场，它们以各自的方式代表测试音的信息。第五，我们结合理论和实验工作，以更好地理解时空神经元激活。我们解释了相互矛盾的MLR神经发生和它们的各种形态，特别是在早期潜伏期，并最终提出它们是由三种活动的组合决定的：皮层放电活动，皮层突触活动，以及远离皮层的其他活动。少

The objective of the present study is to establish design guidelines for developing neural prosthesis that restores lost sensory functions due to disorders of sensory cells or pathways. The achievements of the study are summarized as follows. First, we developed an experimental animal model of the auditory brainstem implant (ABI) that directly stimulates the cochlear nucleus in the brainstem to restore the hearing of deaf patients who had their auditory nerves removed. The model included a surface microelectrode array for auditory cortical recording and a spike microelectrode arrray for the microstimulation in the cochlear nucleus. Second, using the ABI model of rats, we demonstrated that the cochlear nuclear microstirnulation could evoke spatio-temporal neural activity in the auditory cortex and the proper stimulation could take after the pure-tone-evoked activation, suggesting that the stimulation could induce a pitch and intensity sensation and thus substantially verifying the capab … More ility of ABI Third, we proposed and verified "the multiple gating stimulation," which can selectively activate nerves placing in between electrodes. The technique broadly generated action potentials with "the cathodic sourte electrodes," and simultaneously blocked unnecessary propagation with "the anodic gate electrodes," resulting in selective propagation in between electrodes. We demonstrated the feasibility via simulations with nerve equations and in vivo experiments of rat spinal cord stimulation Forth, our cortical auditory evoked potential (AEP) mapping demonstrated that the rat auditory cortex is divided into the multiple auditory fields, which represent the information of test tones in their respective manner. Fifth, we combined theoretical and experimental works to better understand the spatio-tempomal neuronal activation. We interpreted the contradictory MLR neurogenesis and their various morphologies particularly within early latency, and finally suggested that they were determined by combination of three activities: cortical firing activities, cortical synaptic activities, and other activities far from cortex. Less