Researchers have produced a prototype polymer device capable of performing one of the functions of a living neuron, the transmission of neurotransmitter chemicals. This is a small step towards a range of technologies important to very long-term goals in repair of the brain and extension of healthy life.
The brain is distinct from other organs in that we will never be able to outright replace more than small sections of it, which limits tissue engineering as an approach to repair in that portion of the central nervous system. Even when tissue engineers are capable of reproducing brain tissue, they will still have to restore existing cells and connections in situ in order to preserve the data of the mind. Eventually a collection of technologies will be needed to achieve this end, and many of them involve some sort of artificial replacement for living neurons. In the case of early applications in this space, such as bypasses for nerve and brain damage, these artificial neurons do not have to be fully functional or even as small as the real thing, but bear in mind that technologies such as the one demonstrated here are just the first step on a long pathway:
Neurons are isolated from each other and communicate with the help of chemical signals, commonly called neurotransmitters or signal substances. Inside a neuron, these chemical signals are converted to an electrical action potential, which travels along the axon of the neuron until it reaches the end. Here at the synapse, the electrical signal is converted to the release of chemical signals, which via diffusion can relay the signal to the next nerve cell. Scientists have now created an organic bioelectronic device that is capable of receiving chemical signals, which it can then relay to human cells.
"Our artificial neuron is made of conductive polymers and it functions like a human neuron. The sensing component of the artificial neuron senses a change in chemical signals in one dish, and translates this into an electrical signal. This electrical signal is next translated into the release of the neurotransmitter acetylcholine in a second dish, whose effect on living human cells can be monitored." The research team hope that their innovation will improve treatments for neurological disorders which currently rely on traditional electrical stimulation. The new technique makes it possible to stimulate neurons based on specific chemical signals received from different parts of the body. In the future, this may help physicians to bypass damaged nerve cells and restore neural function. "Next, we would like to miniaturize this device to enable implantation into the human body."