It seems that growing miniature brains in the lab just wasn’t good enough for neuroscientists, as a group of researchers have now constructed an artificial neuron that works like the real thing. Amazingly, the fake cell manages to capture the fundamental signal-transmitting function of neurons and can communicate with real human cells, all in the absence of any living parts.
But there is more to the idea behind this synthetic neuron than simply proving that it can be done. The team reckons that in the future, it might be possible to actually use these devices in patients to replace damaged nerves, for example, to help treat injury or disease. They may also have a place in the prosthetics industry as surgeons may be able to use them as a bridge between a person’s tissue and an artificial limb, allowing for greater control of movement. You can find out more about this fascinating invention in Biosensors and Bioelectronics.
Neurons, or nerves, are specialized cells whose role is to process and transmit information to other cells. In order to communicate, they release chemical signals, or neurotransmitters, across a small intercellular gap known as a synapse. These chemicals are then taken up by the adjoining cell and converted into an electrical signal, or action potential, that propagates along the neuron’s spindly axon. When it reaches the other end, the electrical signal is once again converted into a chemical signal that gets released across the synapse, ready to trigger the entire process again.
To mimic this, scientists at Sweden’s Karolinska Institutet used conductive molecules, or polymers, to build the neuron, connecting enzyme-based biosensors to organic bioelectronics. The sensors pick up chemical changes in their surrounding environment, induced by the researchers, which is then translated into an electrical signal by an electronic pump that functions to control the flow of charged ions, much like the channels that exist across neuronal membranes. Finally, the electrical signal is turned back into a chemical signal, involving the release of a neurotransmitter in a different dish, which can then act on human cells.
With further development and miniaturization, the researchers believe that these cells could have a place outside the laboratory, and possibly inside the human body.
“We foresee that in the future, by adding the concept of wireless communication, the biosensor could be placed in one part of the body, and trigger the release of neurotransmitters at distant locations,” lead researcher Agneta Richter-Dahlfors said in a statement. “Using such auto-regulated sensing and delivery, or possibly a remote control, new and exciting opportunities for future research and treatment for neurological disorders can be envisaged.”