A mouse was blind, but now it sees

Only science, it seems, can make us daydream about the “what ifs” of life in the fashion a study today does.

What if blind people could see again?

A group of scientists announced in an article in a science journal they’ve been able to restore sight to blind mice.

Time.com says Andrew Huberman, an associate professor of neurobiology at Stanford University, found that a combination of visual stimulation of the optic nerve, helped along by chemical, can regrow nerve extensions, called axons, and coax them to stretch out again and find their way back to make connections to the parts of the brain that allows us to see.

About three weeks after the optic nerves in the mice were damaged, the researchers saw evidence of axons extending back into the brain from the eye, something that previous efforts to regenerate eye nerves haven’t done with much reliability. The combination of keeping the damaged but remaining axons stimulated, by exposing the mice to bars on a screen that are moving in different directions, and the nerve growth factors lead to a 500-fold increase in axon regrowth. Granted, not all of the axons managed to sprout again, but those that did were able to do so with impressive speed and distance to reach the brain.

When the researchers conducted four different tests to verify how much of the regrowth contributed to actual restoration of vision in the animals, the animals passed two of the tests that detected large objects and movement.

“For the longest time people in the field wondered if neurons could regenerate and form the correct patterns to connect to the brain, and we found that they did,” says Huberman.

The most compelling finding is that the study suggest that once nerves are coaxed to grow again, they retain the instructions to find their proper connections in the brain’s visual center. If nerves growing toward the brain are like visitors to New York’s Grand Central Station, these nerves are like well-equipped travelers with maps and specific instructions for finding their destination. “It means that neurons remember the way home; they never forget,” says Huberman.

Animal rights supporters aren’t going to like this one bit. To do the experiments, researchers first had to crush the optic nerve in mice.