OBJECTIVE The analysis of interactions among local populations of neurons in the cerebral cortex (e.g. within cortical microcolumns) requires high resolution and high channel count recordings from chronically implanted laminar microelectrode arrays. The request for high-density recordings of a large number of recording sites can presently only be accomplished by probes realized using complementary metal-oxide-semiconductor (CMOS) technology. In preparation for their use in non-human primates, we aimed for neural probe validation in a head-fixed approach analyzing the long-term recording capability. APPROACH We examined chronically implanted silicon-based laminar probes, realized using a CMOS technology in combination with micromachining, to record from the primary visual cortex (V1) of a monkey. We used a passive CMOS probe that had 128 electrodes arranged at a pitch of 22.5 µm in four columns and 32 rows on a slender shank. In order to validate the performance of a dedicated microdrive, the overall dimensions of probe and interface boards were chosen to be compatible with the final active CMOS probe comprising integrated circuitry. MAIN RESULTS Using the passive probe, we recorded simultaneously local field potentials (LFP) and spiking multiunit activity (MUA) in V1 of an awake behaving macaque monkey. We found that an insertion through the dura and subsequent readjustments of the chronically implanted neural probe was possible and allowed us to record stable LFPs for more than five months. The quality of MUA degraded within the first month but remained sufficiently high to permit mapping of receptive fields during the full recording period. SIGNIFICANCE We conclude that the passive silicon probe enables semi-chronic recordings of high quality of LFP and MUA for a time span exceeding five months. The new microdrive compatible with a commercial recording chamber successfully demonstrated the readjustment of the probe position while the implemented plug structure effectively reduced brain tissue movement relative to the probe.

中文翻译：

---

使用长期植入的128通道无源硅探针在猕猴中进行高密度电生理记录。

目的分析大脑皮层（例如皮层微柱内）局部神经元之间的相互作用需要长期植入的层状微电极阵列的高分辨率和高通道数记录。目前，只能通过使用互补金属氧化物半导体（CMOS）技术实现的探针来实现对大量记录位置进行高密度记录的要求。在准备将其用于非人类灵长类动物中时，我们旨在通过分析固定的长期记录能力的固定式神经探针进行验证。方法我们检查了采用CMOS技术结合微加工实现的长期植入的硅基层状探针，以记录猴子的主要视觉皮层（V1）。我们使用了一个无源CMOS探针，该探针在细长杆上的4列和32行中以22.5 µm的间距排列有128个电极。为了验证专用微驱动器的性能，选择了探头和接口板的总体尺寸，使其与包括集成电路的最终有源CMOS探头兼容。主要结果使用无源探针，我们同时记录了一只清醒的猕猴的V1的局部场电位（LFP）和尖峰多单位活性（MUA）。我们发现有可能通过硬脑膜插入并随后重新调整长期植入的神经探针，这使我们能够记录稳定的LFP超过五个月。MUA的质量在第一个月内下降，但仍然足够高，可以在整个记录期间映射接收场。意义我们得出的结论是，无源硅探头可以在超过五个月的时间范围内对LFP和MUA进行高质量的半同步记录。与商业记录室兼容的新型微型驱动器成功演示了探头位置的重新调整，同时所采用的插头结构有效地减少了相对于探头的脑组织运动。