MOTES: Micro-scale Opto-electronically Transduced Electrode Sites

摘要 我们在这个项目中的目标是开发一种新型的电子记录设备，它可以补充和填充- 对尖端成像技术的支持。鉴于多电记录提供了详细的 神经活动的测量具有很高的时间精度，它还具有侵入性，提供相对较低的空间 分辨率，并且几乎没有提供有关所测量神经元的身份的信息。光学成像技术， 相反，提供了非常精细的空间分辨率，简化了神经识别，但代价是显著 较差的时间分辨率，以及化学(通过荧光染料)或遗传的要求 对组织进行修饰。为了更好地连接这两种模式，我们设想开发不受限制的 微尺度光电传感电极(MOTES)将光电子元件组合在一起 电源和与定制CMOS电路的通信，以实现低噪声放大和编码 信号。每个Mote将由光学刺激的微型光伏电池供电，并将使用产生的 1-2微瓦的电功率用于测量、放大和编码电生理信号，上行链路 通过驱动LED以光学方式传输信息。Motes将避免许多与标准 线材和刀柄为主的电极，其中植入的电极体积最大，所以大多数 它造成的组织损伤，源于连接电极位置和外部电子设备的长而坚硬的小腿。 最有用的是，Motes的光伏电池将被设计成从相同的光刺激中获取电力 在成像神经活动时，用于激发荧光的波长和强度。同样， 用于上行链路的LED将被设计为发射波长和强度与 可被荧光成像系统检测到的。这些选择将允许光纤下行链路和上行链路 现有成像系统只需最小修改即可处理信号。通过使用脉冲 刺激(如在多光子系统中使用的)以及适当地编码和定时上行链接的LED脉冲， 荧光和尘埃排放可以被分到相邻的亚微秒时间箱中。这 光学兼容性和时间多路复用的组合将允许同时成像和电学 从相同体积的神经组织记录神经活动，使用相同的光学成像和 录音系统。这种同步的、不同种类的测量能力将实现更大的范围 神经活动的实验和研究比目前可能的更多。

Summary Our goal in this project is to develop a new class of electrical recording device that complements and piggy- backs on cutting edge imaging technologies. Whereas multi-electrical recording has provided detailed measurements of neural activity with high temporal precision, it is also invasive, provides relatively low spatial resolution, and provides little information about the identity of measured neurons. Optical imaging techniques, conversely, provide very fine spatial resolution, easing neural identification, but at the cost of significantly worse temporal resolution, and with the requirement of either chemical (through fluorescent dyes) or genetic modification of the tissue. In order to better bridge these two modalities, we envision developing untethered Microscale Optoelectronically Transduced Electrodes (MOTEs) which combine optoelectronic elements for power and communication with custom CMOS circuits for low-noise amplification and encoding of electrical signals. Each MOTE will be powered by optically stimulated micro-photovoltaic cells and will use the resulting 1-2µW of electrical power to measure, amplify, and encode electrophysiological signals, up-linking this information optically by driving an LED. MOTEs will avoid many of the problems associated with standard wire- and shank-based electrodes, where most of the volume of the implanted electrode, and so most of the tissue damage it does, stems from the long rigid shank that connects electrode sites to external electronics. To be most useful, MOTEs' photovoltaics will be designed to harvest power from optical stimuli of the same wavelengths and intensities as are used in stimulating fluorescence when imaging neural activity. Similarly, the LED used for uplink will be designed to emit light at wavelengths and intensities consistent with those detectable by a fluorescent imaging system. These choices will allow the both down- and up-link of optical signals to be handled by existing imaging systems with minimal modification. By employing a pulsed stimulation (as is used in multi-photon systems) and appropriately encoding and timing up-linked LED pulses, fluorescent and MOTE emissions can be segregated into adjacent sub-microsecond time bins. This combination of optical compatibility and temporal multiplexing will allow simultaneous imaging and electrical recording of neural activity from the same volume of neural tissue, using the same optical imaging and recording systems. This simultaneous, heterogeneous measurement capability will enable a much wider range of experiments and studies of neural activity than are presently possible.