Abstract
Optical methods for viewing neuronal populations and projections in the intact mammalian brain are needed, but light scattering prevents imaging deep into brain structures. We imaged fixed brain tissue using Scale, an aqueous reagent that renders biological samples optically transparent but completely preserves fluorescent signals in the clarified structures. In Scale-treated mouse brain, neurons labeled with genetically encoded fluorescent proteins were visualized at an unprecedented depth in millimeter-scale networks and at subcellular resolution. The improved depth and scale of imaging permitted comprehensive three-dimensional reconstructions of cortical, callosal and hippocampal projections whose extent was limited only by the working distance of the objective lenses. In the intact neurogenic niche of the dentate gyrus, Scale allowed the quantitation of distances of neural stem cells to blood vessels. Our findings suggest that the Scale method will be useful for light microscopy-based connectomics of cellular networks in brain and other tissues.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Newborn
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Brain / cytology*
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Brain / embryology
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Brain / growth & development
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Cell Proliferation
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Embryo, Mammalian
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Glycerol / metabolism
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Glycerol / pharmacology
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Imaging, Three-Dimensional / methods*
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Intermediate Filament Proteins / metabolism
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Luminescent Proteins / genetics
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Luminescent Proteins / metabolism
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Mice
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Mice, Transgenic
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Microscopy, Fluorescence / methods*
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Nerve Tissue Proteins / metabolism
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Nestin
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Neural Cell Adhesion Molecule L1 / metabolism
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Neural Stem Cells / physiology
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Neurons / cytology*
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Neurons / metabolism*
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Octoxynol / metabolism
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Receptors, AMPA / metabolism
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Sialic Acids / metabolism
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Synaptophysin / metabolism
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Thy-1 Antigens
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Time Factors
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Tissue Fixation / methods*
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Urea / metabolism
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Urea / pharmacology
Substances
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Intermediate Filament Proteins
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Luminescent Proteins
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Nerve Tissue Proteins
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Nes protein, mouse
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Nestin
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Neural Cell Adhesion Molecule L1
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Receptors, AMPA
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ScaleA2 solution
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Sialic Acids
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Synaptophysin
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Thy-1 Antigens
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polysialyl neural cell adhesion molecule
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Urea
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Octoxynol
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Glycerol
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glutamate receptor ionotropic, AMPA 1