Brain’s Cerebellum Could Help Direct Prosthetic Limbs

Tapping the power of the small brain region called the cerebellum could improve patients’ ability to move cutting-edge robotic limbs, a new study suggests.

The cerebellum is an ancient structure located under the brain, just above where the spinal cord connects to the brain.

This structure has largely been overlooked by prosthetics researchers in favor of the cerebral cortex, which is the outermost layer of tissue covering the brain, researchers noted.

But lab studies with rats show that the cerebellum can play a key role in controlling the movement of objects using brain waves.

“The cerebellum has a well-known role in movement but has been ignored in neuroprosthetic research,” said researcher Tanuj Gulati, an assistant professor of biomedical sciences and neurology at the Cedars-Sinai Center for Neural Science and Medicine, in Los Angeles.

“We are the first to record what is happening in the cerebellum as the brain learns to manipulate these devices, and we found that its involvement is essential for device use,” Gulati added in a Cedars-Sinai news release.

Currently, experimental robot devices are controlled with brain waves through electrodes permanently implanted in regions of the cerebral cortex known to help manage movement of the human body.

This technique has allowed patients to control robot limbs, motorized wheelchairs and computer keyboards, researchers noted.

To see how the cerebellum contributes to motor control, researchers trained lab rats to move a robotic water tube using electrodes planted in their motor cortex and their cerebellum.

“We found that activity of the neurons in the cerebellum was coordinated with the motor cortex, and that activity in the cerebellum was critical for neuroprosthetic task performance,” said lead researcher Aamir Abbasi, a postdoctoral scientist in Gulati’s lab.

When researchers silenced neurons in the outer layer of the cerebellum – where the cerebellum receives input from the rest of the brain — the lab rats had a tough time getting the pipe to move and deliver water to them, the study says.

And when researchers silenced neurons deep in the cerebellum — which are responsible for communicating out to the rest of the brain — the rats had trouble maintaining accurate control of the pipe.

The findings were published April 12 in the journal Science Advances.

“These results could help make neuroprosthetics an option for patients with damage to the motor cortex due to brain injury, stroke or diseases such as Parkinson’s or multiple sclerosis,” said researcher Dr. Nancy Sicotte, chair of neurology at Cedars-Sinai. “It’s possible that, eventually, implants in the cerebellar region could be used to help these patients manipulate external devices.”

Including input from the cerebellum also could help iron out continuing problems with existing brain-controlled devices, added David Underhill, chair of biomedical sciences at Cedars Sinai.

“This study suggests that some of those [problems] could be resolved by involving the cerebellum as well as the motor cortex to help patients gain use of neuroprosthetic devices more quickly and improve their ability to control them accurately,” Underhill said.

More information

The Cleveland Clinic has more about the cerebellum.

SOURCE: Cedars-Sinai Medical Center, news release, April 12, 2024