Research Supported by The Tow Foundation Reveals Small Part Brain That Steadies The Body
New scientific research has revealed how a small part of the brain singlehandedly steadies the body if it is thrown off balance. The study in mice found that a brain region called the lateral vestibular nucleus, or LVN, accomplishes this feat by moving muscles in a two-step, kneejerk response that first widens the animal's center of gravity, and then strengthens and stabilizes its limb muscles and joints. These findings provide powerful evidence that the LVN is the key to animals' ability to maintain balance, while also offering insight into the mechanics of how animals stay upright when unexpected changes occur beneath their feet.
"Whether it's tripping on an uneven patch of sidewalk or negotiating a wobbly balance beam, we can all recall times when we've nearly lost our balance—only to be saved by some quick reflexes," said Thomas M. Jessell, PhD, codirector of Columbia's Mortimer B. Zuckerman Mind Brain Behavior Institute and the paper's senior author. "Today's findings in mice suggest that reflexes like these may be driven by a predictable process guided by the LVN, a brain region that appears to be dedicated to one thing: keeping the body on its feet."
Decades of research has shown that multiple brain regions are involved in different aspects of balance. But which regions were involved in the reactive parts of balance—how an animal maintains its stance after experiencing a disturbance—remained unclear.
To get to the root of balance in the brain, the researchers first trained mice to walk across a balance beam, while the beam was nudged at specific intervals. After being momentarily thrown off balance, the mice almost always steadied themselves and continued on their way. Throughout this activity, researchers monitored muscle activity in the animals' limbs...