Trainable biohybrid neurons
In 2017, researchers from Stanford University presented a new device made of organic materials that simulates an effective learning process of the nervous system with low energy consumption. It was an artificial version of the synapse, the space through which neurotransmitters move to communicate between neurons. In 2019, researchers assembled nine artificial synapses into a matrix, showing that they can be simultaneously programmed to simulate parallel brain activity.
In their new study, a team from Stanford University, in collaboration with researchers from the Italian Institute of Technology and the Eindhoven University of Technology in the Netherlands, tested the first biohybrid version of an artificial synapse and demonstrated that it can bind to living cells. Future technologies based on the operation of the new device will be able to function by reacting directly to chemical signals of the brain.
Many devices are being developed in different laboratories that can be integrated into brain tissue. And if other devices require an electrical signal to detect and process brain messages, the connection between the Stanford artificial synapse and living cells occurs through electrochemical reactions – as if it were another neuron receiving messages from its neighbor.
How neurons learn
A biohybrid artificial synapse consists of two soft polymer electrodes separated by a trough that is filled with an electrolyte solution, like a synaptic cleft separating communicating neurons in the brain. If living cells are placed on top of one electrode, the neurotransmitters they secrete can react with it to form ions. The ions then pass through the gap to the second electrode and modulate it into a conducting state. Some of these changes are preserved by simulating the learning process taking place in nature, which is very effective from the point of view of energy, because calculations and storage in memory occur in one action. In traditional computer systems, data is first processed and then moved to storage.
To test their invention, the researchers used rat neuroendocrine cells that release dopamine. This neurotransmitter interacted with the device and caused a permanent change in the electrodes after the first reaction.
The first step
The biohybrid design is at an early stage, so the main task of the current study was simply to make it work.
Now that the researchers have successfully tested their device, they are looking for options for future research, which may include working with brain-based computers, brain-computer interfaces, medical devices or new research tools in the field of neuroscience. Already, the authors are working to make the device function in more complex biological conditions that contain different types of cells and several neurotransmitters.
Article by S.T.Keene et al. A biohybrid synapse with neurotransmitter-mediated plasticity is published in the journal Nature Materials.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on Stanford News Service: Stanford researchers develop artificial synapse that works with living cells.