Muscle and nerve connection brought outside of the body

Researchers at MIT have developed a method of replicating neuromuscular junctions outside the body.

The size of a quarter, the microfluidic device contains a muscle strip and a set of motor neurons that can interact with each other with a reaction to light. By shining light on the device, researchers can stimulate the cells to send signals to the muscle fibers. The muscle fibers can be stimulated at multiple frequencies, allowing researchers to study how stress on muscles affects them over time.

"The neuromuscular junction is involved in a lot of very incapacitating, sometimes brutal and fatal disorders, for which a lot has yet to be discovered," said Sebastien Uzel, who led the work as a graduate student in MIT's Department of Mechanical Engineering. "The hope is, being able to form neuromuscular junctions in vitro will help us understand how certain diseases function."

The device, after further development, may one day be able to treat neuromuscular disorders and be personalized to each patient.

"You could potentially take pluripotent cells from an ALS patient, differentiate them into muscle and nerve cells, and make the whole system for that particular patient," said Roger Kamm, a mechanical and biological engineering professor at MIT. "Then you could replicate it as many times as you want, and try different drugs or combinations of therapies to see which is most effective in improving the connection between nerves and muscles."

On the flip side, he says the device may be useful in "modeling exercise protocols." For instance, by stimulating muscle fibers at varying frequencies, scientists can study how repeated stress affects muscle performance.