Researchers connect neurons to computers to decipher the enigmatic code of neuronal circuits

July 12, 2011
Researchers connect neurons to computers to decipher the enigmatic code of neuronal circuits

Machine logic is based on human logic. But although a computer processor can be dissembled and dissected in logical steps, the same is not true for the way our brains process information, says Mark Shein of Tel Aviv University's School of Electrical Engineering.

Doctoral student Shein and his supervisors, Prof. Yael Hanein of the School of Electrical Engineering and Prof. Eshel Ben-Jacob of the School of Physics and Astronomy, want to understand the brain's logic. They have developed a new kind of a lab-on-a-chip platform that may help neuroscientists understand one of the deepest mysteries of our –– how communicate and work together. The chip was recently described in an issue of the journal PLoS ONE.

Within it, Shein has applied advanced mathematical and engineering techniques to connect neurons with electronics and understand how neuronal networks communicate. Hoping to answer ultimate questions about how our work, the researchers believe their tool can be also used to test new drugs. It might also advance artificial intelligence and aid scientists in rewiring artificial limbs to our brain.

Shedding light on a black box

There are relatively simple neural "firing" patterns that can be measured with sensory organs like the ears or eyes, but researchers know little about deep thought processes. Could the brain's electrical signals reveal the basis of thought itself?

"When we look at the neuronal networks operating in the ears or eyes, we have some idea about the coding schemes they utilize," explains Shein. A researcher can apply a stimulus such as a bright light, for example, and then monitor responses in the eye's neurons. But for more complex processes, like "thinking" or operating different sensory inputs and outputs together, "we are basically looking into a black box," he says.

The brain is composed of a daunting number of circuits interconnected with other countless circuits, so understanding of how they function has been close to impossible. But using engineered brain tissue in a Petri dish, Shein's device allows researchers to see what's happening to well-defined neural circuits under different conditions. The result is an active circuitry of neurons on a man-made chip. With it they can look for patterns in bigger networks of neurons, to see if there are any basic elements for information coding.

Investigating the activity of single neurons is not enough to understand how a network functions. With nanotechnological systems and tools, now researchers can explore activity patterns of many neurons simultaneously. In particular, they can investigate how several groups of neurons communicate with each other, says Shein.

The hierarchy of the brain

With these network engineering techniques, the scientists cultured different sized networks of neuronal clusters. Once they looked at these groups, they found rich and surprising behaviors which could not be predicted from what scientists know about single neurons.

The researchers were also able to measure patterns from nerve activity, at nodes where a number of nerves converged into networks. What they detected appears to show that neural networks have a hierarchical structure — large networks are composed of smaller sub-networks. This observation, and a unique setup using electrodes and living nerves, allowed them to create hierarchical networks in a dish.

The brain's circuits work like codes. They can see the patterns in the networks and simplify them, or control connectivity between cells to see how the neuronal network responds to various chemicals and conditions, the scientists report. One theory, proposed by Prof. Ben-Jacob, is that the human brain stores memories like a holograph of an image: small neural networks contain information about the whole brain, but only at a very low resolution.

So far the researchers are able to reveal that clusters of as few as 40 cells can serve as a minimal but sufficient functional network. This cluster is capable of sustaining neural network activity and communicating with other clusters. What this means exactly will be the next question.

Explore further: Brain cell networks recreated with new view of activity behind memory formation

Related Stories

Controlling brain circuits with light

May 3, 2011

F1000 Biology Reports, the open-access, peer-reviewed journal from Faculty of 1000, today published a historical account of the beginnings of the optogenetic revolution by Edward Boyden.

Recommended for you

Imaging technique maps serotonin activity in living brains

October 20, 2016

Serotonin is a neurotransmitter that's partly responsible for feelings of happiness and for mood regulation in humans. This makes it a common target for antidepressants, which block serotonin from being reabsorbed by neurons ...

ALS study reveals role of RNA-binding proteins

October 20, 2016

Although only 10 percent of amyotrophic lateral sclerosis (ALS) cases are hereditary, a significant number of them are caused by mutations that affect proteins that bind RNA, a type of genetic material. University of California ...

Overcoming egocentricity increases self-control

October 19, 2016

Neurobiological models of self-control usually focus on brain mechanisms involved in impulse control and emotion regulation. Recent research at the University of Zurich shows that the mechanism for overcoming egocentricity ...

Exercise may help ward off memory decline

October 19, 2016

Exercise may be associated with a small benefit for elderly people who already have memory and thinking problems, according to new research published in the October 19, 2016, online issue of Neurology, a medical journal of ...

Going for a run could improve cramming for exams

October 19, 2016

Ever worried that all the information you've crammed in during a study session might not stay in your memory? The answer might be going for a run, according to a new study published in Cognitive Systems Research.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jul 18, 2011
This kind of research is just amazing. I mean I love chemistry and physics but there's something crazy about creating a network of neurons, reading signals, then getting some kind of usuable information of how they are working together... How close are we to actually understanding what they are "saying"? I'd wager we are in for some big changes within the next couple decades.

Star trek and other series had some pretty "out there" ideas, but once again, it seems relality is still succeeding in just being that much more amazing.

If I don't live long enough to have a few spare brains lying around that I just plug into when I need more power, that's just gonna suck.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.