Brain on a chip
Growing brain cells in a laboratory may lead to a better understanding of how neurons form computing circuits and process information. Kate Prestt reports.
Researchers at ANU are conducting an amazing experiment in their quest for a major breakthrough in neuroscience.
Perhaps we could find ways to repair brain damage or disorders without the need for a neuroprosthetic.
They wanted to observe how cells, isolated from the brains of rodents, grow and whether they form predictable circuits.
They began by making tiny wires that were shaped into a scaffold, to guide the growth of the brain cells.
These nanowires were mounted on a semiconductor wafer or microchip, as a platform for the experiment.
Observing how brain cells grow, establish connections with neighbouring neurons and eventually form circuits, should provide a greater understanding of the inner workings of the brain.
Lead researcher Dr Vini Gautam says studying how cells connect with each other could one day also help researchers repair damaged parts of the brain.
“The project will provide new insights into the development of neuroprosthetics which can help the brain recover after damage due to an accident, stroke or degenerative neurological diseases,” she says.
Neuroprosthetics are devices that use electrodes to interface with the nervous system, and aim to restore function that has been lost. Cochlear implants are the best known example of such devices.
The ANU study is the first to show that neuronal circuits grown on the nanowire scaffolds were functional and highly interconnected, opening the potential to apply this design to neuroprosthetics.
Gautam’s postdoctoral fellowship brings together the research expertise of Dr Vincent Daria from The John Curtin School of Medical Research (JCSMR), Professor Chennupati Jagadish from the Research School of Physics and Engineering and Dr David Nisbet from the Research School of Engineering.
Daria, the project group leader, says the brain-on-a-chip project may lead to a better understanding of how neurons form computing circuits and eventually process information in the brain.“Neurons need to connect synaptically, which forms the basis of information processing in the brain during sensory input, cognition, learning and memory,” he says.
We are still scratching the surface on what we know about the brain and how we think and form ideas.
“By understanding the brain from a very simple circuit, perhaps we could find ways to repair brain damage or disorders without the need for a neuroprosthetic.
“We are still scratching the surface on what we know about the brain and how we think and form ideas.
“Going to the neuronal or cellular level may give us a much better insight to understand the big picture of how the brain works.
“There is a lot that you can’t prove within a living brain so if we can use an artificial environment where neurons grow similar to that of the brain, we can look at the neurons in high resolution under a microscope. We can stimulate them and watch them grow and form circuits.”
Using a particular nanowire geometry, the team has shown that the neurons are highly interconnected and form predictable functional circuits.
“We were able to make predictive connections between the neurons and demonstrate them to be functional, with neurons firing synchronously,” Daria says.
As a trained physicist, Gautam has always had an interest in biology. During her PhD in India, she used materials used in solar cells to stimulate retinal neurons for applications in bionic vision.
When she moved to Australia to join her husband in Canberra, she got in touch with Professor Jagadish, who is a pioneer in nanotechnology, to explore if he had any roles open in his team. He didn’t have a position available at the time and suggested other options.
Weeks later when Gautam found no job openings, she again got in touch with Jagadish. He said he had been thinking about using the nanowires to engineer neurons.
“But I didn’t know the first thing about neurons so I suggested Vini speak to Vincent Daria at JCSMR who works on neurons,” he says.
“Luck had it that Vincent had a casual research assistant leaving the next week.”
Gautam says she enjoys her project as it uses physics, engineering and neuroscience principles, making it both challenging and exciting.
“Working across disciplines requires communication in different languages, with people from diverse backgrounds,” she says.
“This is challenging but it’s improving my ability to talk about my research.
“This work could open up a new research model that builds up a stronger connection between materials nanotechnology with neuroscience.”
Associate Professor David Nisbet who works with biomaterials at the ANU Research School of Engineering is Gautam’s current Postdoctoral Fellowship supervisor.
“This research project has wide-reaching applications, from understanding fundamental biological processes that occur during brain development, through to the development of technologies for neural prosthetics,” he says.
“We need to continue to mentor Dr Gautam so she secures funding to continue her research and develop an independent research team."
The nanowire scaffolds were fabricated by the group led by Professor Jagadish at the Research School of Physics and Engineering.
“Our research continues to build on the technology that has already been developed for other applications including lasers and solar cells and we are now able to use that for an entirely different application,” he says.
“Without Dr Gautam we would talk about working on this project but nothing would have happened. Her work has shown that we can not only engineer neurons using nanotechnology but see them talk to each other.”
He says many young researchers like Gautam face the challenge of being on a short-term contract. “It is really hard for them to plan out experiments and wrap up things in one year,” he says.
He says bringing together the expertise of people from different disciplines makes bigger things happen, with more impact.