Current neuroprosthetics rely on stable, high quality recordings from chronically implanted microelectrode arrays (MEAs) in neural tissue. While chronic electrophysiological recordings and electrode failure modes have been reported from rodent and larger non-human primate (NHP) models, chronic recordings from the marmoset model have not been previously described. The common marmoset is a New World primate that is easier to breed and handle compared to larger NHPs and has a similarly organized brain, making it a potentially useful smaller NHP model for neuroscience studies. This study reports recording stability and signal quality of MEAs chronically implanted in behaving marmosets. Six adult male marmosets, trained for reaching tasks, were implanted with either a 16-channel tungsten microwire array (five animals) or a Pt-Ir floating MEA (one animal) in the hand-arm region of the primary motor cortex (M1) and another MEA in the striatum targeting the nucleus accumbens (NAcc). Signal stability and quality was quantified as a function of array yield (active electrodes that recorded action potentials), neuronal yield (isolated single units during a recording session), and signal-to-noise ratio (SNR). Out of 11 implanted MEAs, nine provided functional recordings for at least three months, with two arrays functional for 10 months. In general, implants had high yield, which remained stable for up to several months. However, mechanical failure attributed to MEA connector was the most common failure mode. In the longest implants, signal degradation occurred, which was characterized by gradual decline in array yield, reduced number of isolated single units, and changes in waveform shape of action potentials. This work demonstrates the feasibility of longterm recordings from MEAs implanted in cortical and deep brain structures in the marmoset model. The ability to chronically record cortical signals for neural prosthetics applications in the common marmoset extends the potential of this model in neural interface research.

中文翻译：

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植入普通狨猴运动皮层和纹状体的微线阵列神经信号的长期稳定性

当前的神经修复术依赖于神经组织中长期植入的微电极阵列 (MEA) 的稳定、高质量记录。虽然啮齿动物和大型非人类灵长类动物 (NHP) 模型已报告了慢性电生理记录和电极故障模式，但狨猴模型的慢性记录以前尚未描述过。普通狨猴是一种新世界灵长类动物，与较大的 NHP 相比，它更容易繁殖和处理，并且具有相似的大脑组织，使其成为神经科学研究中潜在有用的小型 NHP 模型。这项研究记录了长期植入狨猴体内的 MEA 的稳定性和信号质量。六只成年雄性狨猴，接受过伸手任务训练，在初级运动皮层 (M1) 的手臂区域植入 16 通道钨微丝阵列（五只动物）或 Pt-Ir 浮动 MEA（一只动物）以及纹状体中针对伏隔核 (NAcc) 的另一个 MEA。信号稳定性和质量被量化为阵列产量（记录动作电位的有源电极）、神经元产量（记录过程中孤立的单个单元）和信噪比（SNR）的函数。在 11 个植入的 MEA 中，有 9 个提供了至少三个月的功能记录，其中两个阵列提供了 10 个月的功能。一般来说，种植体的产量很高，可以在长达几个月的时间内保持稳定。然而，MEA 连接器造成的机械故障是最常见的故障模式。在最长的植入中，出现了信号衰减，其特征是阵列产量逐渐下降、孤立的单个单元的数量减少以及动作电位波形形状的变化。这项工作证明了在狨猴模型中植入皮层和深部大脑结构的 MEA 进行长期记录的可行性。在普通狨猴中长期记录皮质信号以用于神经修复应用的能力扩展了该模型在神经接口研究中的潜力。