NIH Director Features “Unique Method” Used by UM Neuroscientist
“Fasten your seat belts! We’re going to fly through the brain of a mouse,” wrote NIH Director Francis S. Collins, M.D., Ph.D., in an article highlighting the work of Xue-Ting Luo, Ph.D., post-doctoral research fellow at The Miami Project to Cure Paralysis, and his mentor Kevin Park, Ph.D., assistant professor of neurological surgery.
Collins is clearly impressed by a unique method used by Luo and Park to visualize neurons in an intact brain, which was among the winners of the Federation of American Societies for Experimental Biology’s 2013 BioArt competition. A video posted along with the article gives viewers a rare close-up of the retinal ganglion cells that carry information from the eye to the brain, where light signals are decoded and translated.
“This acknowledgement from Dr. Collins is incredible, but the credit belongs to Ting, the post-doc in my lab who has done the hard work to harness the technology in our model system,” Park said.
To make the movie, Luo injected a fluorescent dye into the mouse eye, which was taken up by the retinal cells and traced out the nerve pathways from the optic nerve into the brain.
The cinematic tour begins just behind the eyeball and follows the optic nerve past the suprachiasmatic nucleus, which Collins notes is critical for circadian rhythms, to the target destination – the superior colliculus. In what looks like “a large bright oval” in the video, the region helps coordinate head and eye movement.
Calling the movie a “tour de force,” Collins says, “As cool as this video is in its own right, it also provides a cutting edge tool to study connections inside the brain – without cutting it into thin slices.”
Luo and Park developed the tool to study diseases that affect the optic nerve. In severe glaucoma, for example, these connections can be lost, leading to blindness. But the Park lab is testing new therapies that may have the potential to regrow the retinal ganglion cells that make up this nerve and reform connections between them. To watch the neurons regrow and to see whether they make it to their target destination, Luo uses fluorescence microscopy to check whether the therapy was successful.
“Recently, Park and his team found that, while some nerve fibers do regrow and find their targets, most seem to be lost and simply meander,” Collins said. “So, his next challenge will be to develop strategies for improving path-finding. The ultimate test will be to see whether these connections actually restore sight.”