An electrical device that can send and receive chemical signals from neurons could be used in brain-machine interfaces
8 August 2022
An artificial neuron that can release and receive dopamine in connection with real rat cells could be used in future human-machine interfaces.
Most brain-machine interfaces measure simple electrical signals in neurons to gain insight into brain function. But much of the information in neural networks, like the brain, is encoded in neurotransmitters like dopamine, chemicals that neurons use to send messages to each other.
“The brain’s native language is chemical, but all current brain-machine interfaces use an electrical language,” he says. Benhui Hu at Nanjing Medical University in China. “So we devised an artificial neuron to duplicate the way a real neuron communicates.”
The neuron consists of a sensor made of a graphene electrode and carbon nanotubes, which can detect when dopamine is released. If the sensor detects enough, a component called a memristor triggers the release of more dopamine at the other end through a heat-activated hydrogel.
Hu and his team showed that the neuron can send and receive dopamine in communication with rat brain cells in a dish. It could also activate a mouse muscle via the sciatic nerve and move a robotic hand.
The artificial neuron’s memristor can change the amount of dopamine that is required to trigger the release of the chemical. This is similar to how neurons in the brain change the amount of neurotransmitters that are sent between connections in response to external stimuli, a trait called plasticity that is essential for learning.
“This actually has great potential to expand to more sophisticated learning systems. You can do a lot of cool new things here,” he says. Yoeri van de Burgt at the Eindhoven University of Technology in the Netherlands.
While the device’s bulk makes it unsuitable for any current brain-machine interface application, the fact that it can chemically communicate in two ways could make it suitable for many different interfaces with the body, such as in prosthetic devices, he says.
Magazine Reference: NatureElectronics, DOI: 10.1038/s41928-022-00803-0
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