Motor neurons (green) form connections with receptor proteins (red) that cluster on muscle fibers (blue) throughout the body. Reguatory proteins guide this wiring. (Credit: Darnell Lab, The Rockefeller University)
Animals, including humans, are in constant motion from subtle grimaces involving only the face to the highly choreographed sequences of steps ballet dancers makes pirouetting across a stage. At its most basic, movement, or action, is the way we influence with the world around us, and the networks of brain cells involved are well-conserved across species. As a result, understanding how networks of neurons guide movement may lead to an understand of the general principles behind how the brain works.
So how does the brain guide our movements and achieve such precision? How are they planned and how does this essential brain function break down in movement disorders such as amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s Disease? How is the motor system, connecting the brain to our muscles, wired and how are these connections honed by experience, such as practicing the piano or swinging a bat? New brain research tools are helping scientists explore these questions. Remarkably, they are also leading to improved prosthetic devices that restore movement and are controlled by thought – by a person’s intention to move.
Eiman Azim, Columbia University's Kavli Institute for Brain Science, discusses recent findings about excitatory neurons needed to make accurate and precise movements, and a second group is inhibitory neurons necessary for achieving smooth movement of the limbs.
Scientists and engineers are improving how social robots are able to help patients undergoing physical rehabilitation, act as teaching aides, work in nursing homes, and be used for other dynamic purposes.
Whether engaged in a chess game or something less obvious, the brain is constantly thinking. Daniel Wolpert, a professor of engineering at the University of Cambridge, admits that a game of chess is an excellent demonstration of the brain at work.