Neuroscientists from Emory University are collaborating with engineers from Georgia Tech to develop a device that will record the electrical signals of muscles used by animals to perform complex skills. They hope to use the device to gain insights into neurological disorders that affect motor control.
The neuroscientists, led by assistant professor Samuel Sober, have developed a prototype that records the electrical activity of neurons as animals learn and repeat skilled movements. They used the device to study a breathing muscle used by Bengalese finches to sing.
However, the prototype device is quite basic. Its 16 electrodes can only record activity from a single muscle. “We can record the electrical activity of a single neuron and large groups of neurons,” says Sober. “What’s missing is the technology to precisely record the electrical signals of the muscles that ultimately control that movement.”
Sober and his team need a much more sophisticated device—and they are collaborating with the engineering lab of Muhannad Bakir, professor at Georgia Tech, to create one. The teams are working to create a sensor array that would contain over 1,000 electrodes to record data from single cells across 10 or more muscles.
It’s no easy task. The array needs to be flexible enough to fit the shape of small muscles used in fine motor skills and to change shape as the muscles move. And the device needs to be small enough to not interfere with the movement of a small animal. In addition, the device needs to be able to record data from a muscle without damaging it (prior approaches relied on wires that could damage muscles when inserted).
Bakir’s team will create a flexible substrate that can support high-density electrodes while being able to adjust to muscle movement. They will then create a 3D integrated circuit of vertically stacked electrodes—“a miniature skyscraper of electrical circuits,” said Bakir. The vertical design will allow the researchers to minimize the device’s size.
“To our knowledge, no one has done what we are trying to do in this project,” Bakir said. “That makes it more difficult, but also exciting because we are entering new space.”
Sober’s team will use the new device to expand its songbird vocalization studies and explore how a mouse’s nervous system controls forelimb muscles used to perform skilled movements.
An early version of the technology will be tested by Sober’s collaborators in three different universities, while also gathering data across more species.
“We know so little about how the brain organizes skilled behaviors,” Sober says. “Once we perfect this technology, we will make it available to researchers in this field around the world, to advance knowledge as rapidly as possible.”
Read more about how engineers are helping with developments in neuroscience at Researchers Create Artificial Nerve System.