Implant allows rats with brain damage to rapidly recover motor skills


Scientists at the University of Kansas School of Medicine and Case Western Reserve University have developed a lightweight, battery-powered device that appears capable of repairing damaged pathways in the brain. The technology holds promise helping individuals who suffer from the damage left by stroke or head injuries.

The research was published in the Proceedings of the National Academy of Sciences.

Randolph J Nudo, professor of molecular and integrative physiology and director of the Landon Center on Aging at the University of Kansas Medical Center, USA and senior author of the study, says the project represents an important step toward developing devices that can be implanted in the brains of stroke patients, soldiers with traumatic brain injuries and others with abnormal brain function.

Nudo worked on the design of a brain prosthesis with Pedram Mohseni, an associate professor of electrical engineering and computer science at Case Western Reserve University in Cleveland, USA. The idea behind the prosthesis, or microdevice, is similar to defibrillators implanted into heart patients. But instead of monitoring the heart, the microdevice monitors neurons firing in the brain. The aim is to restore communication patterns that have become disrupted by injury or disease.

“We are basically trying to reproduce the process that the brain uses during development, and that it tries to accomplish after injury, but with electronic components that will artificially bridge these areas,” Nudo says.

In order to test the idea, the components were scaled to fit a rat-sized brain. Powered by a simple watch battery, the microdevice was implanted into rats with damaged frontal cortexes. The microdevice was designed to record signals in one part of the brain and then translate them into electrical impulses that stimulate another part of the brain. Nudo and his colleagues wanted to see if the artificial communication could help the brain-injured rats recover their motor skills.

To determine if recovery had taken place, the rats were tested on their ability to reach for a food pellet. The task required some skill as the rats had to reach through an opening in a Plexiglas chamber. 

Without help from the device, rats with brain injuries struggled to reach for and grasp the pellets. When the device was switched on, they were able to perform the task with ease. In fact, after two weeks of microdevice-delivered brain stimulation, the rats were performing approximately at pre-injury levels.

The next step is to design and build a device for testing on primates, with the eventual goal of taking into clinical trials with humans. If successful, the microdevice could augment — and in some cases replace — rehabilitation therapy.

Nudo and Mohseni presented a commercialisation plan for the technology at the American Society for Artificial Internal Organs conference in 2012. The plan won first prize at the conference’s first annual Medical Device Entrepreneur’s Forum. 

The research was funded by the Department of Defense Traumatic Brain Injury-Investigator-Initiated Research Award Program under Awards W81XWH-10-1-0741/0742 and the American Heart Association under Award 09BGIA2280495. The Advanced Platform Technology Center, a Veterans Affairs Research Center of Excellence affiliated with Case Western Reserve University, supported the fabrication costs for the chip in the microdevice.