Artificial Neuron


Scientists Have Built Artificial Neurons That Fully Mimic Human Brain Cells

https://www.sciencealert.com/scientists-build-an-artificial-neuron-that-fully-mimics-a-human-brain-cell

FIONA MACDONALD
29 JUN 2015

Researchers have built the world’s first artificial neuron that’s capable of mimicking the function of an organic brain cell - including the ability to translate chemical signals into electrical impulses, and communicate with other human cells.

These artificial neurons are the size of a fingertip and contain no ‘living’ parts, but the team is working on shrinking them down so they can be implanted into humans. This could allow us to effectively replace damaged nerve cells and develop new treatments for neurological disorders, such as spinal cord injuries and Parkinson’s disease.

"Our artificial neuron is made of conductive polymers and it functions like a human neuron," lead researcher Agneta Richter-Dahlfors from the Karolinska Institutet in Sweden said in a press release.

Until now, scientists have only been able to stimulate brain cells using electrical impulses, which is how they transmit information within the cells. But in our bodies they're stimulated by chemical signals, and this is how they communicate with other neurons.

By connecting enzyme-based biosensors to organic electronic ion pumps, Richter-Dahlfors and her team have now managed to create an artificial neuron that can mimic this function, and they've shown that it can communicate chemically with organic brain cells even over large distances.



This means that artificial neurons could theoretically be integrated into complex biological systems, such as our bodies, and could allow scientists to replace or bypass damaged nerve cells. So imagine being able to use the device to restore function to paralysed patients, or heal brain damage.

"Next, we would like to miniaturise this device to enable implantation into the human body," said Richer-Dahlfors.“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 release of neurotransmitters at distant locations."

"Using such auto-regulated sensing and delivery, or possibly a remote control, new and exciting opportunities for future research and treatment of neurological disorders can be envisaged," she added.

The results of lab trials have been published in the journal Biosensors and Bioelectronics.

We're really looking forward to seeing where this research goes. While the potential for treating neurological disorders are incredibly exciting, the artificial neurons could one day also help us to supplement our mental abilities and add extra memory storage or offer faster processing, and that opens up some pretty awesome possibilities.




ARTIFICIAL NEURONS FOR REPLACING DAMAGED NERVE CELLS



https://europe.medtronic.com/xd-en/transforming-healthcare/EUreka/innovation-articles/artificial-neurons-for-replacing-damaged-nerve-cells.html

Dr Agneta Richter-Dahlfors

Marie Gethins
October 2016


Opening a score of exciting possibilities, Swedish researchers have built the world’s first artificial neuron to mimic organic brain cell function. Importantly, the artificial neuron can translate chemical signals into electrical impulses, opening the potential for communication with other human cells. This remarkable research offers interesting potential for future treatments to help paralyzed and Parkinson’s Disease patients, among others.

Doctor Agneta Richter-Dahlfors and her team at the Karolinska Institutet’s Department of Neuroscience in Sweden have created artificial neurons by connecting enzyme-based biosensors to organic electronic ion pumps. With an infectious diseases background, Richter-Dahlfors explains that initially the team developed the device to induce calcium fluxes with specific frequencies as this happens within the host during infection. They tested various chemicals for transportation. She says, "We tried acetylcholine just for fun because it always has a positive charge and it worked like boom! It super efficiently transported."

Previous brain cell stimulation research had been limited by only being able to stimulate the cells by electrical impulses, while in the human body they are stimulated by chemical signals, enabling them to communicate with other neurons. "At the end of the axon there is a synapsis and it’s not the electrical signal that moves across to the next cell, it’s the chemical substances. The electrical signal along the axon is translated to chemical output. You have chemical input translated to an electronic signal that is translated to a chemical output", explains Richter-Dahlfors.

The team’s artificial neuron mimics the body’s organic electronic pumps function and have demonstrated that not only can it communicate effectively with organic brain cells, but communication can be over long distances. This means that in theory the artificial neurons eventually could be implanted in humans to bypass or even replace damaged nerve cells. Made of conductive polymers, they function like organic human neurons. Electronic control of delivery also means that there is the potential to send signals anywhere in the body through wireless communication. She notes that because there is an electronic on/off control, only the right number of molecules that are required would be delivered each time. However, more research is needed to learn what number of molecules is needed in each situation.

With both electronic and medical innovations accelerating in parallel, Richter-Dahlfors predicts the research could merge into very exciting applications. She suggests, "You can think of having a sensory function in one place, say the brain, and your delivery device at a muscle some distance away, say a muscle in the leg." This offers clear potential for paralyzed patients, including those with spinal cord injuries, as well as patients with other muscle control disorders including Parkinson’s Disease. Auto-regulated sensing and delivery or via a remote control device could facilitate rehabilitation and long-term treatments for many patients suffering from neurological disorders.

Another area that offers interesting potential for the artificial neurons is ph regulation by proton transport. Richter-Dahlfors also highlights regulation of micro environments, such as infection site research in vitro. "We had a paper where we used these conducting polymers to modulate the local micro environment when we used a sensor for the C-reactive protein for effective binding to the C-reactive protein receptor to see what conditions you need to get that binding. It could show what is happening at the local tissue site during infection. There are very few methods today where you can make these dynamic studies," she says.

Finger-tip sized, dimension is one challenge for artificial neuron development, but the team is working on miniaturization. Richter-Dahlfors explains, "If you think of the deep brain stimulation electrodes that exist, that’s the size it needs to be at a later stage when clinicians begin to work on this. The miniaturization will depend on where it is delivered."

REFERENCES

1 Joakim Isaksson, Peter Kjäll, David Nilsson, Nathaniel Robinson, Magnus Berggren, Agneta Richter-Dahlfors, "Electronic control of Ca2+ signalling in neuronal cells using an organic electronic ion pump" In Nature Materials (2007) Available here: http://www.nature.com/nmat/journal/v6/n9/abs/nmat1963.html

2 Daniel T. Simon, Sindhulakshmi Kurup, Karin C. Larsson, Ryusuke Hori, Klas Tybrandt, Michel Goiny, Edwin W. H. Jager, Magnus Berggren, Barbara Canlon, Agneta Richter-Dahlfors, "Organic electronics for precise delivery of neurotransmitters to modulate mammalian sensory function" In Nature Materials (2009) Available here: http://www.nature.com/nmat/journal/v8/n9/abs/nmat2494.html

3 Daniel T. Simon, Karin C. Larsson, David Nilsson, Gustav Burström, Dagmar Galter, Magnus Berggren, Agneta Richter-Dahlfors, "An organic electronic biomimetic neuron enables auto-regulated neuromodulation" In Biosensors and Bioelectronics (2015) Available here: http://www.sciencedirect.com/science/article/pii/S0956566315300610

4 S. Löffler, A. Richter-Dahlfors, "Phase angle spectroscopy on transparent conducting polymer electrodes for real-time measurement of epithelial barrier integrity" In J. Mater. Chem. B (2015) Available here: http://pubs.rsc.org/is/content/articlehtml/2015/tb/c5tb00381d

5 T. Goda, P. Kjall, K. Ishihara, A. Richter-Dahlfors, Y Miyahara, "Biomimetic interfaces reveal activation dynamics of C-reactive protein in local microenvironments" In Advanced Healthcare Materials (2014) Available here: http://www.ncbi.nlm.nih.gov/pubmed/24700816

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