Dual GRIN lens two-photon endoscopy for high-speed volumetric and deep brain imaging.
Yu-Feng ChienJyun-Yi LinPo-Ting YehKuo-Jen HsuYu-Hsuan TsaiShih-Kuo ChenShi-Wei ChuPublished in: Biomedical optics express (2020)
Studying neural connections and activities in vivo is fundamental to understanding brain functions. Given the cm-size brain and three-dimensional neural circuit dynamics, deep-tissue, high-speed volumetric imaging is highly desirable for brain study. With sub-micrometer spatial resolution, intrinsic optical sectioning, and deep-tissue penetration capability, two-photon microscopy (2PM) has found a niche in neuroscience. However, the current 2PM typically relies on a slow axial scan for volumetric imaging, and the maximal penetration depth is only about 1 mm. Here, we demonstrate that by integrating a gradient-index (GRIN) lens and a tunable acoustic GRIN (TAG) lens into 2PM, both penetration depth and volume-imaging rate can be significantly improved. Specifically, an ∼ 1-cm long GRIN lens allows imaging relay from any target region of a mouse brain, while a TAG lens provides a sub-second volume rate via a 100 kHz ∼ 1 MHz axial scan. This technique enables the study of calcium dynamics in cm-deep brain regions with sub-cellular and sub-second spatiotemporal resolution, paving the way for interrogating deep-brain functional connectome.
Keyphrases
- high speed
- high resolution
- resting state
- white matter
- functional connectivity
- atomic force microscopy
- cerebral ischemia
- particulate matter
- single molecule
- magnetic resonance
- multiple sclerosis
- high throughput
- fluorescence imaging
- high frequency
- single cell
- subarachnoid hemorrhage
- brain injury
- high intensity
- heart rate
- water soluble