In this paper, the researchers mapped out the neural circuitry and found that the key to integrating sensory information with the necessary corresponding motor function is a group of sensory neurons on the spinal cord that connect with the RORα neurons that bridge to the brain’s motor region. Together, it serves as a “mini-brain” that facilitates balance under difficult circumstances.

"We think these neurons are responsible for combining all of this information to tell the feet how to move," lead author Steeve Bourane added. "If you stand on a slippery surface for a long time, you'll notice your calf muscles get stiff, but you may not have noticed you were using them. Your body is on autopilot, constantly making subtle corrections while freeing you to attend to other higher-level tasks.”

Disabling this circuitry in mice revealed that while they could still walk under normal conditions, when the terrain got more difficult, they were incapable of making the small foot adjustments in order to maintain balance and walk smoothly. Getting a better understanding of this pathway and other mechanisms the brain uses to process sensory information could lead to improved therapies for those affected by spinal cord disease or trauma.

http://www.cell.com/cell/abstract/S0092-8674(15)00012-4 http://www.cell.com/cell/abstract/S0092-8674(15)00012-4