A multi-foci objective lens for large scale brain activity recording

用于大规模大脑活动记录的多焦点物镜

基本信息

批准号：
10731905
负责人：
CHRIS XU
金额：
$ 32.8万
依托单位：
CORNELL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2025-08-31
项目状态：
未结题

项目摘要

Abstract The goal of this project is to develop a novel bifocal catadioptric objective that will allow large-scale recording of neural circuits in vivo. The objective will enable faster volumetric imaging of large brain regions by simultaneous two-photon (2P) imaging of shallow layers and three-photon (3P) imaging of deep layers of brain tissues with improved collection efficiency. Although three-photon microscopy (3PM) allows imaging at depths inaccessible by two photon microscopy (2PM), 2P excitation generates larger fluorescence signal with lower excitation pulse energy when imaging at shallow tissue layers. Therefore, for fast imaging across a large depth, the optimum approach is to use 2PM for the superficial layers and 3PM for the deeper regions simultaneously. Implementation of this approach inevitably requires the objective lens to generate two focal planes that are separated by a large axial distance while still maintaining high spatial resolution and large field of view. Simultaneous 2PM and 3PM will not only allow for utilization of the advantages of both modalities but also for faster volumetric imaging of large brain columns. We will develop a bifocal catadioptric (i.e., both refractive and reflective) lens based on the idea of separation the optical paths of the excitation light with different wavelengths. The lens will feature two focal planes separated axially by ~ 600 µm for the 2P (< 1100 nm) and 3P (>1200 nm) excitation wavelengths. The design approach also separates the excitation path and the collection path and allows independent optimization for efficient collection of the emitted fluorescence. The bifocal objective will collect fluorescence back through non-imaging pathways, which enables the proposed catadioptric objective to have a large collection numerical aperture and a large collection field of view. The collection efficiency is approximately 5x higher than the commercially available objective lenses when imaging deep (>1 mm) into the mouse brain. Improving the signal collection efficiency will immediately increase the frame rate without increasing the excitation power, enabling high-resolution, high-speed imaging at these depths. We will design, fabricate and validate the novel objective lens and will combine it with focus-tunable lenses to enable faster volumetric imaging of mouse brains. The successful completion of this program will immediately enable simultaneous 2P and 3P imaging across a large range of depth (~ 1.2 mm), such as recording population of neurons across different layers of mouse brains. The technology developed within this program will have potential impacts in a large number of biomedical fields such as neuroscience, immunology, and cancer biology.

抽象的该项目的目标是开发一种新型双焦折反射物镜，可以大规模记录该目标将能够通过同时对大脑区域进行更快的体积成像。脑组织浅层双光子（2P）成像和深层脑组织三光子（3P）成像尽管三光子显微镜 (3PM) 可以在难以到达的深度进行成像。通过双光子显微镜 (2PM)，2P 激发以较低的激发脉冲产生更大的荧光信号因此，对于大深度的快速成像，这是最佳选择。方法是对浅层使用 2PM，对深层区域同时使用 3PM。这种方法不可避免地需要物镜产生两个相距很大的焦平面轴向距离，同时仍保持高空间分辨率和大视场同时 2PM 和 3PM。不仅可以利用两种模式的优点，还可以更快地进行体积成像我们将开发一种基于大脑柱的双焦点折折射（即折射和反射）镜片。分离不同波长激发光的光路的想法该透镜将具有两个特征。对于 2P (< 1100 nm) 和 3P (>1200 nm) 激发波长，焦平面轴向间隔约 600 µm。该设计方法还将激励路径和收集路径分开，并允许独立优化有效收集发射的荧光双焦点物镜将收集荧光。通过非成像路径返回，这使得所提出的折反射物镜能够拥有大量的集合数值孔径和大收集视场，收集效率大约高出 5 倍。改善小鼠大脑深处（>1毫米）成像时的市售物镜。信号采集效率会立即提高帧率，而无需增加激励功率，我们将设计、制造和验证这种新颖的技术，以实现在这些深度的高分辨率、高速成像。物镜并将其与可调焦镜头结合起来，以实现更快的小鼠大脑体积成像。该计划的成功完成将立即实现跨区域同时 2P 和 3P 成像大范围的深度（~ 1.2 mm），例如记录小鼠大脑不同层的神经元数量。该计划开发的技术将对许多生物医学领域产生潜在影响例如神经科学、免疫学和癌症生物学。