Nanoscale volumetric fluorescence imaging via photochemical sectioning

Area of Science:

• Neuroscience
• Biophysics
• Microscopy

Background:

• Advancements in hydrogel-based tissue clearing and expansion have enabled optical nanoscopy of biological specimens.
• High-resolution fluorescence microscopes face limitations in imaging depth, hindering whole-mount specimen studies.

Purpose of the Study:

• To develop a method for imaging whole-mount specimens at nanoscale resolution without physical sectioning.
• To overcome the limited imaging depth of current high-resolution microscopes.

Main Methods:

• Development of "photochemical sectioning," a light-based sample sectioning technique.
• Combination of photochemical sectioning with volumetric lattice light-sheet imaging.
• Utilizing petabyte-scale computation for image reconstruction.

Main Results:

• Successful nanoscale imaging and reconstruction of axons and myelination sheaths across entire mouse olfactory bulbs.
• Identification of distinct patterns of axon degeneration and de-/dysmyelination in a neurodegenerative mouse model.
• Demonstration of peta- to exabyte-scale super-resolution imaging capabilities.

Conclusions:

• Photochemical sectioning, combined with advanced imaging and computation, enables nanoscale studies of large biological specimens.
• This approach provides new insights into neurodegenerative processes at the level of axons and myelin.
• The methodology holds significant potential for future large-scale, high-resolution biological investigations.