Untethering Electrophysiology in Vivo: An Optical Nanoscale Semiconductor Array f

描述（由申请人提供）：神经系统中信息处理的大规模并行性质要求同时和在体内对许多神经元的电活动进行准确的感知和记录。到目前为止，这在哺乳动物身上都是可能的，在有限的程度上，也有可能是不拴绳的，但在昆虫身上却不行。基本的限制是神经探针的大小和重量。我们的建议是开发基于光子晶体（PC）纳米腔激光器的纳米级神经探针，可用于无系留神经传感和体内记录。这些探测器将由光驱动，能够以预先指定的波长传输测量信号。一组这样的探测器在数百到数千个不同的波长上工作，将使人们能够并行地、实时地记录和分析大量的神经活动。探针将包括一个电场传感器，该传感器可以调制光泵浦PC纳米腔激光器的输出功率或中心波长。传感器和纳米腔激光器都将集成到III-V族化合物半导体膜中，该膜将以现代纳米制造工艺制造。这一过程将使数以万计的新型器件的低成本生产成为可能。作为我们的实验平台，我们将使用果蝇的早期嗅觉系统。当探针被插入果蝇触角上的一个感受器底部时，它将接收到由2-4个嗅觉感觉神经元将它们的树突投射到该感受器上所产生的局部场电位。这个局部场势将被编码成探针上的纳米腔激光器发射的光波。最后，利用光学数据采集系统捕获光波并解码局部场势。结合已经开发的精确气味传递和测量系统以及神经系统识别的理论进展，一系列这样的不受束缚的探针将使我们非常详细地了解气味是如何在时间和空间上由嗅觉感觉神经元代表的，并将有助于更深入地了解高级大脑中心的气味信号处理。此外，我们计划在自然环境中监测自由运动的嗅觉感觉神经元的神经活动。一个由20到30个纳米探针组成的阵列将被插入天线中，并在自由光线下进行监测。鉴于纳米半导体探针的体积和重量非常小，功能灵活，成本低，我们还设想它们可用于无系绳神经传感和记录，在各种脊椎动物和无脊椎动物的感觉和运动系统中。

DESCRIPTION (provided by applicant): The massively parallel nature of information processing in neural systems calls for an accurate sensing and recording of the electrical activity of many neurons simultaneously and in-vivo. Until now, this has been possible with both tethered and, to a limited extent, untethered solutions in mammals, but not in insects. The fundamental limitations were size and weight of neural probes. Our proposal calls for the development of nanoscale neural probes based on photonic crystal (PC) nanocavity lasers that can be used for untethered neural sensing and recording in-vivo. The probes will be optically powered and capable of transmitting measured signals at pre-specied wavelengths. An array of such probes operating at hundreds to thousands of dierent wavelengths will allow one to record and analyze massive amounts of neural activity in parallel and in real-time. The probes will include an electric field sensor that modulates either the output power or the center wavelength of an optically pumped PC nanocavity laser. Both the sensor and the nanocavity laser will be integrated into a III-V group compound semiconductor membrane that will be fabricated in a modern nanofabrication process. This process will enable a low-cost production of tens of thousands of novel devices in parallel. As our testbed, we will use the early olfactory system of the fruit fly Drosophila Melanogaster. When inserted at the base of a sensillum on the fly's antenna, the probe will pick up the local eld potential generated by 2-4 olfactory sensory neurons projecting their dendrites into that sensillum. This local field potential will then be encoded into a lightwave emitted by the nanocavity laser on the probe. Finally, an optical data acquisition system will be used to capture the lightwave and decode the local field potential. Combined with an already-developed system for precise odorant delivery and measurement as well as theoretical advances in neural system identication, an array of such untethered probes will give us an exceptionally detailed insight into how odorants are represented by olfactory sensory neurons both in time and space and will aid in developing a deeper understanding of odor signal processing in higher brain centers. Furthermore, we plan to monitor the neural activity of olfactory sensory neurons in freely moving ies in a natural environment. An array consisting of 20 to 30 nanoprobes will be inserted into the antennae and monitored in free ight. Given the extraordinarily small size and weight, flexible functionality and low cost of nanofabricated semiconductor probes, we also envision them being used for untethered neural sensing and recording in a wide variety of sensory and motor systems of both vertebrates and invertebrates. PUBLIC HEALTH RELEVANCE: We propose to build nanoscale photonic devices that would enable an untethered recording of neural activity in the early olfactory system of fruit flies. These devices will make it possible to record a y's neural activity in response to odorants in free ight and will aid in developing a deeper understanding of odor signal processing both in the periphery and in higher brain centers. This in turn will help us understand the neural basis of conditions such as anosmia, the inability to perceive odors.