Long-term stability of intracortical recordings using perforated and arrayed Parylene sheath electrodes
Long-term stability of intracortical recordings using perforated and arrayed Parylene sheath electrodes
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DOI：
10.1088/1741-2560/13/6/066020
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发表时间：
2016-12-01
影响因子：
4
通讯作者：
Pikov, Victor
中科院分区：
文献类型：
--
作者：
Hara, Seth A.;Kim, Brian J.;Pikov, Victor
Objective.用皮质内神经探针获取可靠和稳健的神经记录是神经修复领域的一个持续挑战。我们开发了一种多电极阵列技术，以解决慢性皮质内记录的可靠性和目前在体内记录的结果。Approach. 2 x 2 Parylene鞘电极阵列（PSEA）是微加工的，仅由Parylene C和铂制成。该探针包括一种新型的三维鞘结构、穿孔和生物活性涂层，可改善组织整合并管理免疫反应。使用顺序浸涂方法施加涂层，该方法覆盖整个探头表面和护套结构的内部。尖锐的穿刺针尖锥度有助于以最小创伤插入。在植入前，通过光学和电子显微镜以及电化学测试对制造的探针进行检查。主要结果。在晶片上成功地制造了1 × 2阵列，然后将其封装在一起以产生2 × 2阵列。然后，选择具有适当电化学性质的电极位点的探针。用生物活性涂层处理阵列的子集以促进神经元生长并抑制炎症，并且将阵列的另一子集与小窝蛋白-1的病毒介导的表达结合植入。将阵列连接到定制的插入穿梭器上，以便于精确插入大鼠运动皮层。在长达12个月的植入期间获得了稳定的电生理记录。个别探针周围的皮质组织的免疫组织化学评价表明，探针的电生理性能和组织学上可观察到的神经元和树突发芽的接近之间的强相关性。意义PSEA证明了鞘电极技术的可扩展性，并提供更高的电极数量和密度，以访问更大的记录体积。本研究为在探针周围创建支持性生物环境以促进柔性探针在大脑皮层中的长期电生理性能的重要性提供了支持。特别是，我们证明了Matrigel涂层和Caveolin-1的长期表达的有益效果。此外，我们提供了支持的想法，使用人工脱细胞组织隔室作为一种方式，以抵消周围的星形胶质细胞瘢痕形成的封闭效应的探针作为一种手段，建立一个更亲密和稳定的神经接口。
Objective. Acquisition of reliable and robust neural recordings with intracortical neural probes is a persistent challenge in the field of neuroprosthetics. We developed a multielectrode array technology to address chronic intracortical recording reliability and present in vivo recording results. Approach. The 2 x 2 Parylene sheath electrode array (PSEA) was microfabricated and constructed from only Parylene C and platinum. The probe includes a novel three-dimensional sheath structure, perforations, and bioactive coatings that improve tissue integration and manage immune response. Coatings were applied using a sequential dip-coating method that provided coverage over the entire probe surface and interior of the sheath structure. A sharp probe tip taper facilitated insertion with minimal trauma. Fabricated probes were subject to examination by optical and electron microscopy and electrochemical testing prior to implantation. Main results. 1 x 2 arrays were successfully fabricated on wafer and then packaged together to produce 2 x 2 arrays. Then, probes having electrode sites with adequate electrochemical properties were selected. A subset of arrays was treated with bioactive coatings to encourage neuronal growth and suppress inflammation and another subset of arrays was implanted in conjunction with a virally mediated expression of Caveolin-1. Arrays were attached to a custom-made insertion shuttle to facilitate precise insertion into the rat motor cortex. Stable electrophysiological recordings were obtained during the period of implantation up to 12 months. Immunohistochemical evaluation of cortical tissue around individual probes indicated a strong correlation between the electrophysiological performance of the probes and histologically observable proximity of neurons and dendritic sprouting. Significance. The PSEA demonstrates the scalability of sheath electrode technology and provides higher electrode count and density to access a greater volume for recording. This study provided support for the importance of creating a supportive biological environment around the probes to promote the long-term electrophysiological performance of flexible probes in the cerebral cortex. In particular, we demonstrated beneficial effects of the Matrigel coating and the long-term expression of Caveolin-1. Furthermore, we provided support to an idea of using an artificial acellular tissue compartment as a way to counteract the walling-off effect of the astrocytic scar formation around the probes as a means of establishing a more intimate and stable neural interface.