The image above shows neurons growing in the spinal cord of a zebrafish embryo. It was made possible by a new technique that combines two imaging technologies, allowing scientists to watch in unprecedented 3-D detail as cancer cells crawl, spinal nerve circuits wire up, and immune cells cruise through a zebrafish’s inner ear.
Physicist Eric Betzig, a group leader at the Howard Hughes Medical Institute’s Janelia Research Campus, and colleagues reported on the work in the journal Science.
For centuries, our sharpest views of living cells have come from cells isolated on glass slides, because the large groups of cells inside whole organisms scramble light like a bagful of marbles. And even when viewing individual cells, most existing microscopes create images too slowly to follow the action inside the cell in three dimension and bathe the cell in intense light that may interfere with its workings.
The new technique combines adaptive optics – the technology astronomers use to “detwinkle” stars viewed through Earth’s turbulent atmosphere – with lattice light-sheet microscopy, which sweeps a razor-thin sheet of light back and forth to collect a series of 2D image that can then be combined to form a high-resolution 3D movie of activity inside cells.