Adaptive optical microscopy for high-accuracy recording of neural activity in vivo

项目总结 为了理解大脑中的计算，我们需要高精度地监测神经回路的活动， 这就需要具有高空间和时间分辨率的方法。非侵入性，有能力解决 亚细胞结构、光学显微镜已广泛应用于神经科学领域，具有多种 开发的方法用于在高速、大深度和/或大空间尺度上对神经活动进行成像。为 例如，发展了自由空间角啁啾增强延迟双光子荧光显微镜来记录 活体脑组织中khz帧频率的膜电压。三光子荧光显微镜--一种新兴的 使用比双光子荧光显微镜更长波长的激发光的方法，具有很大的 该仪器具有穿透深度，能够对小鼠大脑中超过1毫米深的结构进行成像。一种替代 点扫描多光子荧光显微镜、单光子宽场荧光显微镜 也被应用于活体监测大脑活动。最常见的情况是，整个样本都被照亮 以及由物镜收集并用相机成像的发出的荧光，这使得快速活动成为可能 浅层结构的成像，有时横向超过毫米。为了获得准确的 然而，对活体神经活动的测量，必须与 当这些显微镜方法应用于脑组织时。生物的光学不均匀性 组织本身会扭曲成像光，并阻止所有显微镜模式实现其设计 活体内的表现。当应用于活动成像时，这种退化可能会导致错误的结论。这里, 我们建议优化和应用冀中星实验室开发的自适应光学方法，以选择尖端的高性能 用于高精度神经测量的快速、大深度和大范围活动记录方式 活体内活动。

PROJECT SUMMARY To understand the computations in the brain, we need to monitor the activity of neural circuits at high accuracy, which requires methodologies with high spatial and temporal resolution. Non-invasive and capable of resolving subcellular structures, optical microscopy has been extensively applied in the field of neuroscience, with a variety of methods developed to image neural activity at high speed, large depths, and/or over large spatial scales. For example, free-space angular-chirp-enhanced delay two-photon fluorescence microscopy was developed to record membrane voltage at kHz frame rate in the brain in vivo. Three-photon fluorescence microscopy, an emerging method that uses excitation light of longer wavelengths than two-photon fluorescence microscopy, has large penetration depths and is capable of imaging structures over 1-mm deep in the mouse brain. An alternative to the point-scanning multiphoton fluorescence microscopy above, single-photon widefield fluorescence microscopy has also been applied to in vivo monitoring of brain activity. Most commonly, the entire sample is illuminated and the emitted fluorescence collected by an objective lens and imaged with a camera, which enables fast activity imaging of superficial structures, sometimes over millimeters in lateral dimension. To obtain accurate measurements of neural activity in vivo, however, one has to combat the degradation of the resolving power of these microscopy methods when they are applied to brain tissue. The optical inhomogeneity of the biological tissue itself distorts the image-forming light and prevents all microscopy modalities from achieving their designed performance in vivo. When applied to activity imaging, such degradation can lead to erroneous conclusions. Here, we propose to optimize and apply adaptive optics methods developed in the Ji lab to select cutting-edge high- speed, large-depth, and large-scale activity recording modalities for high-accuracy measurements of neural activity in vivo.