"Cell" surprised to discover a neuron that controls 'walking'

Walking is the most natural movement

As one might expect, it is the brain that initiates the movement

The coordination of many of our walking muscles is handled by neurons in the spinal cord, said Mentis, associate professor of pathology and cell biology (neurology) at Columbia University Vagelos College of Physicians and Surgeons

It's a complex job: Under precise timing, these neurons must send signals that alternate the activity of the left and right legs -- left, right, left, right -- so that the flexors and extensors of each leg shrink alternately

Most scientists believe that such complex tasks can only be accomplished by complex circuits of neurons, whose contributions come from different types of neurons

But Mentis's latest research shows that within the ensemble of these circuits, only one type of neuron is entirely responsible for keeping our legs in step

Like little instructors, we'd never get anywhere without these neurons collectively commanding, "left, right, left, right

These neurons—ventral spinocerebellar tract neurons, to be precise—make contact with other spinal cord neurons and coordinate the ability of muscles to move

In the new study, Mentis and his colleagues found that in freely moving adult mice, only those cells were chemically silenced, and the animals were unable to function normally

Mentis also found that these cells are highly interconnected, a property that may help them generate the complex rhythmic patterns necessary for movement

This finding has important implications for the development of new treatments for patients with spinal cord injuries or movement disorders

"For example, in someone with a spinal cord severed, it may not be enough to just connect the brain and spinal cord," Mentis said

Control of mammalian locomotion by ventral spinocerebellar tract neurons.