High density chronic optogenetic interface for primate brains

项目总结 了解非人灵长类(NHP)大脑皮层神经回路的功能，该模型 最接近人类的系统，对于理解正常的皮质功能和人类的电路水平基础至关重要 大脑紊乱。光遗传学已成为研究神经回路功能的有力工具，但也面临着挑战 仍然适用于国家卫生计划。在大型NHP大脑中，大体积操作是必不可少的，以便 观察可测量的电生理或行为效应，并了解信息的编码 多个脑区。在之前的NIH大脑计划资助下，一个由 犹他州大学已经开发并在体内测试了犹他州光电极阵列(UOA)。这是一个10x10的阵列 穿透式透明光导，结合到µLED阵列，用于大体积、时空图案化 大型大脑中神经回路的光遗传调制。NHP视皮层尿酸的活体检测 证明该装置允许选择性地激活深层皮质，以及病灶和 通过简单地改变同时激活的µLED的数量和/或它们的光来实现大规模光刺激 辐照度这些结果使UOA成为研究局部和大容量靶向的有力工具 大型大脑中的神经元群。在BlackRock Neurotech的领导下，这项STTR的目标是将UOA 通过结合其目前‘LED STIM’光遗传表面的最佳特征而变成可商业化的设备 使用UOA的刺激阵列。因此，第一阶段的目标是设计这种新设备的第一次迭代， 目标1：集成蓝色刺激阵列，其中重新设计， 两级刺激装置的制造和集成将使用独立的10×10和 9×9蓝色微米LED阵列，分别用于深层和表面刺激。目标2：设备封装和 包装，其中强大的封装工艺将被开发和测试，适合急性活体使用。 目标3：开发矩阵驱动程序，其中将开发新的驱动程序和固件，以便 独立控制深度和表面刺激阵列，进行空间多路复用操作。该项目 包括Go-NoGo到阶段II范例，它要求&gt；90%的刺激点保持活动&gt；2.8 MW/mm2经过急性浸泡测试，在10%的占空比下50%同时运行，无伪影。阶段 II将包括四个目标：目标4：针对多色刺激的器件优化，其中有源µLED 组件将进行修改，以便于将µLED放置和硬封装到 设备，允许在每个深部/表面部位进行多色刺激。单色和双色设备都将 在第二阶段生产。目标5：设备封装和打包，将建立在目标2工作的基础上，以包括 对器件的有源成分进行硬封装，以增加器件在体内的可靠性。流程 将被开发和测试，适合在体内长期使用。目标6：开发双色矩阵驱动器，在 该矩阵驱动器将被更新为双极驱动信号，以实现对每个微米LED的多路复用控制 刺激部位。目标7：NHP的活体测试，其中OA2设备的急性和慢性测试将 在猕猴中表演长达6个月的时间。

PROJECT SUMMARY Understanding the function of neural circuits in the cerebral cortex of the non-human primate (NHP), the model system closest to human, is crucial to understanding normal cortical function and the circuit-level basis of human brain disorders. Optogenetics has become a powerful tool for studying neural circuit function, but challenges remain in its application to NHPs. Large volume manipulations are essential in the large NHP brain in order to observe measurable electrophysiological or behavioral effects and understand the encoding of information across multiple brain areas. Under previous NIH BRAIN Initiative funding, an interdisciplinary team led by the University of Utah has developed and tested in vivo the Utah Optrode Array (UOA). This is a 10x10 array of penetrating transparent light guides, bonded to a µLED array, for large-volume, spatiotemporally patterned optogenetic modulation of neural circuits in large brains. In vivo testing of the UOA in NHP visual cortex demonstrated that the device allows for selective activation of deep cortical layers, as well as for both focal and large-scale photostimulation by simply varying the number of simultaneously activated µLEDs and/or their light irradiance These results establish the UOA as a powerful tool for studying local and large-volume targeted neuronal populations in large brains. Led by Blackrock Neurotech, the goal of this STTR is to transition the UOA into a commercializable device by combing the best features of its current ‘LED Stim’ optogenetic surface stimulation array with the UOA. Thus, the goal of Phase I is to engineer the first iteration of this new device, termed ‘OA2’ for development purposes: Aim 1: Integration of blue stimulation array, in which redesign, fabrication, and integration of the two-level stimulation device will be performed using independent 10×10 and 9×9 arrays of blue µLEDs for deep-layer and surface stimulation, respectively. Aim 2: Device encapsulation and packaging, in which robust encapsulation processes will be developed and tested, suitable for acute in vivo use. Aim 3: Development of matrix driver, in which a new driver and firmware will be developed in order to independently control the deep and surface stimulation arrays for spatially-multiplexed operation. The project includes a Go-NoGo to phase II paradigm which requires >90% of the stimulation sites to remain active >2.8 mW/mm2 following acute soak testing with 50% simultaneous operation at 10% duty cycle, artifact-free. Phase II will consist of four Aims: Aim 4: Device optimization for multi-color stimulation, in which the active µLED component will be modified to facilitate placement and hard encapsulation of µLEDs onto the topside of the device, allowing multi-color stimulation at each deep/surface site. Both single and two-color devices will be produced in Phase II. Aim 5: Device encapsulation and packaging, will build upon the work of Aim 2 to include hard encapsulation of the active components of the device in order to increase device in vivo reliability. Processes will be developed and tested suitable for chronic in vivo use. Aim 6: Development of dual-color matrix driver, in which the matrix driver will be updated to bipolar drive signals to enable multiplexed control of two µLEDs per stimulation site. Aim 7: In vivo testing in NHP, in which both acute and chronic testing of the OA2 device will be performed in macaque for periods up to 6 months.