Fluorescent Nerves

NERVE MARKER Injecting mice with a nerve-specific fluorescent probe makes the nerves glow under two wavelengths of light (middle, and top right). A tumor-specific probe highlights the tissue to be removed (bottom right).
Credit: Michael A. Whitney Et Al/Nature Biotechnology

A new way to make nerves glow could protect them during surgery

Source: “Fluorescent Peptides Highlight Peripheral Nerves During Surgery In Mice”

Quyen T. Nguyen et al.

Nature Biotechnology online, February 6, 2011

Results: Researchers from the university of California, San Diego, developed a fluorescent peptide that binds specifically to nerve tissue. Two hours after it was injected into mice, all the animal’s peripheral nerves glowed when illuminated with a specific wavelength of light. The effect lasted for several hours. Researchers showed that the marker also identifies nerves in human tissue.

Why it matters: An easy way to visualize nerves should help surgeons avoid damaging them during delicate procedures. Nerve damage during surgery can lead to chronic pain and paralysis and, in the case of prostate operations, incontinence or erectile dysfunction. Existing methods of identifying nerves label only a single tract of nerves and can take days to do so.

Methods: To create nerve-specific probes, researchers first created a library of viruses that infect only bacteria and display different peptides, short chains of amino acids, on their coats. They then exposed nerve tissue to the viruses, looking for the peptide that bound most specifically to peripheral nerves. Attaching a fluorescent molecule to the target peptide created a glowing marker easily detectable under certain wavelengths of light.

Next steps: Additional animal testing will be needed before the marker is ready to be tested in people. The technology has been licensed by Avelas Biosciences, a biotech startup, which is currently looking for private or industrial partnerships to develop it.