Brain’s “steering wheel” mechanism found in mice

It goes without saying that the brain is incredibly complex, and we’re still figuring out which bits do what. Movement, and specifically walking, is one of the most fundamental actions an animal can take, and now scientists at the University of Copenhagen have found the brain’s “steering wheel” mechanism in mice.

The control center for walking is mostly in the spinal cord itself, and doesn’t require too much input from the brain. That saves us from thinking about each step directly. And while many of the circuits involved are already well known, there are still some specific functions that remain unclear.

In the new study, the researchers found a group of neurons that directly control whether mice turn left or right. Located in the brain stem, these neurons express a molecule called Chx10 to signal the spinal cord when to turn and in which direction. Basically, these neurons will activate on one side of the brain at a time, causing the animal to turn in that direction.

“The control is done by simply applying the ‘brake’ to the walking movement on the side that the mice turn to – then the muscles will contract on the same side,” says Jared Cregg, first author of the study. “In this way, the length of the steps on one side becomes short and on the other side long, making the mouse turn. Thus, the Chx10 cells constitute a motor turning system – a kind of steering wheel.”

It might sound like a pretty basic mechanism, but improving our understanding of how the brain functions is important. By knowing how things are supposed to work, it can point scientists in the right direction for finding new ways to treat problems when things go wrong. In this case, the researchers say that it opens up new potential treatment targets for things like Parkinson’s and other neurological disorders that lead to problems with walking.

The research was published in the journal Nature Neuroscience. The team describes the work in the video below.

Cells in the brain stem of mice control right and left walking

Source: University of Copenhagen

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