Computational Miniature Mesoscope for Cortex-wide, Cellular resolution Ca2+ Imaging in Freely Behaving Mice

摘要 感知和认知产生于跨越不同大脑的大型神经元网络的协调活动 区域。了解它们的紧急行为需要在内部和跨区域进行大规模的活动测量 区域，理想情况下为单个单元格分辨率。对大脑动力学的综合理解需要细胞尺度 超过一厘米的感觉、运动和执行区域的数据。此外，功能 大脑区域之间的相互作用随着动机状态和行为目标的不同而不同，从自由生成数据 动物的移动尤为关键。因此，一个关键目标是能够测量整个范围内的活动 当动物参与复杂的认知要求的行为时，大脑皮层处于细胞分辨率。然而， 传统的荧光显微技术不能满足视场、分辨率和分辨率的联合要求 小型化。在这里，我们提出了一种计算微型介镜(CM2)，它将使皮质- 自由行为小鼠的宽细胞分辨率钙离子成像。前提是计算成像 利用高级算法克服传统光学技术的局限性，显著扩展成像范围 能力。在我们的原理验证系统中，我们演示了在8x7mm2的视野中进行单次拍摄的3D成像 和7微米分辨率的散射模体(Sci.Adv.2020)，并实现了组织学上的单细胞分辨 横断面。我们的可穿戴原型现在已经展示了感官驱动的神经活动的可视化 头部固定和自由活动小鼠的主嗅球均为4x4mm2。在这个项目中，我们将：(目标1) 先进的CM2硬件，以实现大脑皮层范围的细胞分辨率成像。我们将对硬件进行验证 改进了模特儿和活体实验。(目标2)开发基于分散信息的深度学习 神经信号的快速而稳健的恢复。我们将在活体实验和基准测试中验证该算法 对照桌面上的1P和2P测量。(目标3)社交活动中的大脑皮层、细胞分辨率的钙离子成像 在行为自由的小鼠中的识别。我们将使用CM2调查跨区域、网络规模的活动 引导熟悉伴侣之间的社交互动的动态--最具综合性、多感官、 以及认知上要求苛刻的神经处理形式。对公众健康的影响：这项工作将建立 强大的支持技术，极大地扩展了行为中可能进行的活动测量的规模 动物，提供了关于分布式皮质功能的广泛问题的途径。作为一个专注的 应用，我们将测试社会行为过程中个体识别的神经特征。我们预料到 我们的方法可以扩展到更广泛的生物学问题，如导航，短的和长的- 术语记忆存储，并可能潜在地导致表征神经中断的新策略 发生在精神疾病和神经退行性疾病中的功能。

ABSTRACT Perception and cognition arise from the coordinated activity of large networks of neurons spanning diverse brain areas. Understanding their emergent behavior requires large-scale activity measurements both within and across regions, ideally at single cell resolution. An integrative understanding of brain dynamics requires cellular-scale data across sensory, motor, and executive areas spanning more than a centimeter. In addition, functional interactions between brain areas vary with motivational state and behavioral goals, making data from freely moving animals particularly critical. Thus, a key goal is the ability to measure activity across the full extent of cortex at cellular resolution as animals engage in complex, cognitively demanding behaviors. However, conventional fluorescence microscopy techniques cannot meet the joint requirements of FOV, resolution, and miniaturization. Here, we propose a Computational Miniature Mesoscope (CM2) that will enable cortex- wide, cellular resolution Ca2+ imaging in freely behaving mice. The premise is that computational imaging leverages advanced algorithms to overcome limitations of conventional optics and significantly expand imaging capabilities. In our proof-of-principle system, we demonstrated single-shot 3D imaging across an 8x7mm2 FOV and 7µm resolution in scattering phantoms (Sci. Adv. 2020), and achieved single-cell resolution on histological sections. Our wearable prototype has now demonstrated visualization of sensory-driven neural activity across the 4x4mm2 main olfactory bulb in both head-fixed and freely moving mice. In this project we will: (Aim 1) advance CM2 hardware to achieve cortex-wide cellular resolution imaging. We will validate the hardware improvement on both phantoms and in vivo experiments. (Aim 2) Develop scattering-informed deep learning for fast and robust recovery of neural signals. We will validate the algorithm on in vivo experiments and benchmark against tabletop 1P and 2P measurements. (Aim 3) Cortex-wide, cellular-resolution Ca2+ imaging during social recognition in freely behaving mice. We will use CM2 to investigate the cross-area, network-scale activity dynamics that guide social interactions between familiar partners - one of the most integrative, multi-sensory, and cognitively demanding forms of neural processing. IMPACT ON PUBLIC HEALTH: This work will establish powerful enabling technology that greatly expands the scale of activity measurements possible in behaving animals, providing access to a wide range of questions about distributed cortical function. As a focused application, we will test the neural signatures of individual recognition during social behavior. We anticipate that our approach can be extended to a broader range of biological questions such as navigation, short- and long- term memory storage, and can potentially lead to new strategies for characterizing the disruptions in neural function that occur in psychiatric disease and neurodegenerative disorders.