Scientists at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have created a special device to be able to stimulate and record signals from and to peripheral nerve fibers on a specialty chip. The device can be used to repeatedly stimulate and record the returning electric activity with high resolution, potentially helping to develop future neuroprosthetic implants that can help restore physical ability and sensory perception in people with a variety of disabilities.
Neuroprosthetics are implantable devices that have electrode arrays that can mimic some of the electrical activity of nerves. For example, spinal cord stimulation can help to restore walking and maybe even bring a sense of touch to prosthetic arms and hands.
Fine tuning of neuroprosthetic devices is currently challenging due to the small number of electrodes that can be currently simultaneously used in real patients. To overcome this, the EPFL team has developed a system that can stimulate and read nerve fibers explanted from the body as though they’re still inside.
The system has tiny microchannels within which electrodes and nerve fibers mimic the functionality of nerve tissues. It was used to stimulate and inhibit neural activity within explanted nerve fibers harvested from the spinal cords of rats. Various techniques were tried to achieve the best results that should be expected if the same would be tried within living animals.
“In vitro tests are usually carried out on neuron cultures in dishes. But these cultures don’t replicate the diversity of neurons, like their different types and diameters, that you would find in vivo. Resulting nerve cells’ properties are changed. What’s more, the extracellular microelectrode arrays that some scientists use generally can’t record all the activity of a single nerve cell in a culture,” said Sandra Gribi, a researcher involved in the project.
Study in Nature Communications: A microfabricated nerve-on-a-chip platform for rapid assessment of neural conduction in explanted peripheral nerve fibers…