The "Mini-Brain" That Helps Us Function

By Sondra Forsyth

Researchers from the Salk Institute have discovered that we unconsciously maintain our balance via a cluster of neurons that acts as a “mini-brain.”

In their study, published in the journal Cell, the scientists “map the neural circuitry of the spinal cord,” according to a news release from the institute. The investigators said that the “circuitry” allows the body to make small adjustments to foot position and balance by using touch sensors in the feet.

The work provides the first blueprint of a spinal circuit that integrates commands from the brain and sensory information from the limbs, the institute said.  The understanding could eventually help in developing therapies for spinal cord injuries and illnesses that affect motor skills and balance.

“When we stand and walk, touch sensors on the soles of our feet detect subtle changes in pressure and movement. These sensors send signals to our spinal cord and then to the brain,” said Martyn Goulding, a Salk professor and senior author on the paper. “Our study opens what was essentially a black box, as up until now we didn’t know how these signals are encoded or processed in the spinal cord. Moreover, it was unclear how this touch information was merged with other sensory information to control movement and posture.”

“How the brain creates a sensory percept and turns it into an action is one of the central questions in neuroscience,” Goulding added. “Our work is offering a really robust view of neural pathways and processes that underlie the control of movement and how the body senses its environment. We’re at the beginning of a real sea change in the field, which is tremendously exciting.”