<aside> ⛈️ 成像基本概念

• **组成：**光学放大系统（目镜与物镜）+ 照明系统（光源和聚光镜）+ 镜架及调节系统
• 光：电磁波（粒子 + 波）；可见光【non-invasive, high resolution, can image and manipulate, can not penetrate deep】

• resolution (seeing smaller and smaller things)：NA, 透光率, 畸变矫正, 景深

  • 分辨率是如何产生的 —— Airy disc
  • 数值孔径（Numerical Aperture，NA）：
  • 光学系统的设计和质量：

• contrast (seeing what you want to see)

  Principle: Light is transmitted through the sample and absorbed by it.

  Application: Very little contrast in unstained specimens. Only useful for specimens that can be contrasted via dyes. With a bright background, the human eye requires local intensity fluctuations of at least 10 to 20% to be able to recognize objects

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  Polarization, birefringence o Fluorescence lifetime o Fluorescence transfer

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What to image in neuroscience

• Molecular composition: Super-resolution imaging (Sparse labeling & sequential imaging, Tissue expansion)
• Structure & connectivity: Two photon microscope for deep tissue imaging; (Trend: Fixed cell/Tissue → Living cell/tissue → Behaving animals; Local structures → Global connectivity)
• Functional dynamics: Imaging deeper, Imaging faster, Imaging freely moving animal
• Integrative dissection:

光学显微镜 (light microscope)

<aside> 🌵 电子显微镜 electron microscopy

透射电子显微镜：观察细胞的超微结构

扫描隧道电子显微镜：观察生物样品表面的立体结构

冷冻电镜：解析生物大分子的结构

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<aside> 🌵 扫描探针显微技术

原子力电子显微镜（AFM）：对单个分子进行操控

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