MOTES: Micro-scale Opto-electronically Transduced Electrode Sites

总结 我们在这个项目中的目标是开发一种新的电子记录设备，补充和猪- 最先进的成像技术。而多电子记录提供了详细的 虽然以高时间精度测量神经活动，但它也是侵入性的，提供相对低的空间分辨率， 分辨率，并提供了很少的信息的身份测量神经元。光学成像技术， 相反，提供非常精细的空间分辨率，便于神经识别，但代价是 更差的时间分辨率，并且需要化学（通过荧光染料）或遗传 组织的改变。为了更好地连接这两种模式，我们设想开发不受约束的 微型光电转换电极（MOTE），其结合联合收割机光电元件， 采用定制CMOS电路实现低噪声放大和电信号编码， 信号.每个MOTE将由光激励微光伏电池供电，并将使用由此产生的 1-2µW的电功率，用于测量、放大和编码电生理信号， 通过驱动LED以光学方式显示信息。MOTE将避免许多与标准 基于线和杆的电极，其中植入电极的大部分体积，因此大部分的 它所造成的组织损伤，源于将电极部位连接到外部电子设备的长的刚性柄。 最有用的是，MOTE的光电转换器将被设计成从相同的光刺激中获取能量。 当成像神经活动时，用于刺激荧光的波长和强度。同样地， 用于上行链路的LED将被设计成以与那些波长和强度一致的波长和强度发射光 可被荧光成像系统检测到。这些选择将允许光通信的下行链路和上行链路 信号由现有的成像系统以最小的修改来处理。通过采用脉冲 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MOTE发射可以被分离到相邻的亚微秒时间仓中。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通信。 使用相同的光学成像，从相同体积的神经组织记录神经活动， 记录系统。这种同时、异构的测量能力将使测量范围更广， 神经活动的实验和研究比目前可能的。

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.