BRIGHT BRAINS: Thomas Deerinck of the University of California, San Diego, captured fine anatomical details of a 400-micron sample of rat cerebellum, coloring the Purkinje neurons green, the glial cells red and the nuclei blue (2-photon microscopy).
For all the delights and horrors human vision provides, it has only one way of collecting information about life: cells in the retina register photons of light for the brain to interpret into images. When it comes to seeing structures too small for the eye to resolve, ones that reflect too few photons for the eye to detect, microscopy must lead the way. The images displayed here, honored in the 2007 Olympus BioScapes Digital Imaging Competition for both their technical merit and their aesthetics, represent the state of the art in light microscopy for biological research.
Call it a renaissance, call it a revolution; in the field of light microscopy, it is well under way. Palettes of light are diversifying as scientists develop new fluorescent markers and new genetic techniques for incorporating them into samples, throwing open doors to discovery. For example, the researchers responsible for this year’s first-prize image employed a new technique, called Brainbow, to turn each neuron in a mouse’s brain a distinct color under the microscope. The method allows them to trace individual axons through a dizzying neuronal mesh and to map the wiring of the brain in a way that was impossible using earlier imaging techniques.
The precision of the tools is changing, too. Individual proteins can be tagged to watch how a molecule walks, and the minute details of cell division and differentiation can be witnessed live. Microscopists can paint fast in broad strokes of light to capture ephemeral events or more slowly in tiny strokes of light to see a piece of life in exquisite detail. And with new innovations in microscope technology, the lacuna between imaging speed and resolution continues to narrow.
The ability to see even the smallest biological structures with a range of techniques and to manage the massive amounts of resulting data builds a powerful, intimate portfolio of life—accessible to all and deeply meaningful to those who understand and wonder at its details.
