What gives humans the dexterity for everything from brain surgery to texting?
Research led by Columbia neuroscientist Thomas M. Jessell, Claire Tow Professor of Motor Neuron Disorders and Co-Director of the Mortimer B. Zuckerman Mind Brain Behavior Institute, has identified a unique genetic signature in the nerve cells that drive the muscles of hands and feet, offering new insight into the origins of fine motor control. Everything from tool-making and writing to drawing and throwing a fastball depends on this type of dexterity.
Jessell and his colleagues focused on the genes that switch on and off in an embryo, wiring up the hands and toes to the central nervous system. Once this system is online, motor neurons that extend from the spinal cord convey signals to the fingers and toes to control fine movements.
When hands, feet, and digits emerged about 400 million years ago, it was a major turning point in evolution, helping the first land animals use fine motor skills like grasping. Jessell’s research uncovers the genetic programs that originated this neural circuitry in tandem with the advent of the extremities.
This discovery may provide insight into diseases like ALS that often begin with muscle weakness in the hands and feet. Now researchers will know how to generate the motor neurons that guide movement in fingers and toes, helping them develop new treatments. Learn more.