Tissue clearing and its applications in neuroscience
authors: Hiroki R. Ueda, Ali Ertürk, Kwanghun Chung, Viviana Gradinaru, Alain Chédotal, Pavel Tomancak, Philipp J. Keller
doi: 10.1038/s41583-019-0250-1
CITATION
Ueda, H. R., Ertürk, A., Chung, K., Gradinaru, V., Chédotal, A., Tomancak, P., & Keller, P. J. (2020). Tissue clearing and its applications in neuroscience. Nature Reviews Neuroscience, 21(2), 61–79. https://doi.org/10.1038/s41583-019-0250-1
ABSTRACT
State-of-the-art tissue-clearing methods provide subcellular-level optical access to intact tissues from individual organs and even to some entire mammals. When combined with light-sheet microscopy and automated approaches to image analysis, existing tissue-clearing methods can speed up and may reduce the cost of conventional histology by several orders of magnitude. In addition, tissue-clearing chemistry allows whole-organ antibody labelling, which can be applied even to thick human tissues. By combining the most powerful labelling, clearing, imaging and data-analysis tools, scientists are extracting structural and functional cellular and subcellular information on complex mammalian bodies and large human specimens at an accelerated pace. The rapid generation of terabyte-scale imaging data furthermore creates a high demand for efficient computational approaches that tackle challenges in large-scale data analysis and management. In this Review, we discuss how tissue-clearing methods could provide an unbiased, system-level view of mammalian bodies and human specimens and discuss future opportunities for the use of these methods in human neuroscience.
There are 3 main methods for tissue clearing - hydrophobic, hydrophilic and hydrogel methods. each have their pros and cons but the goal is to remove lipids, pigments and decalcify to make the specimen as clear as possible
light sheet microscopy allows for fast 3d imaging of the entire brain. its higher signal to noise and higher resolution than 2p imaging.
hydrophobic tissue clearing is fast and simple. it shrinks the brain a lot for easier imaging. the solvents use also preserve the specimen well.
hydrophilic tissue clearing is good because there are high levels of biosafety and compatibility and protein functions are preserved, so you can keep fluorescent proteins intact for example.
hydrogel based tissue clearing remove all lipids from the tissue but preserved structural integrity and minimizes loss of biomolecules
tissue clearing is really useful for tracing long range projections