Cybernetics

Public release date: 16-Oct-2002 Back to Eurekalert

Contact: Claire Bowles
claire.bowles@rbi.co.uk
44-207-331-2751
New Scientist

Brain on a chip
ZOMBIE brains could soon become a powerful tool for drug developers. A biotech company has developed a way to keep slices of living brain tissue alive for weeks, allowing researchers to study the effect of chemicals on entire neural networks, not just individual cells.
"We are building stripped-down mini-brains, if you will, directly on a chip," says Miro Pastrnak, business development director of Tensor Biosciences of Irvine, California. He says the "brain-on-a-chip" could help drugs developers find better treatments for a host of neurological and psychiatric disorders, from Alzheimer's disease to schizophrenia. Tensor may already have found a more effective treatment for anxiety this way.

"Behaviour is the result of the electrical activity of billions of brain cells connected in complex circuits, not the activity of a cell or a receptor acting in isolation," says Pastrnak. And psychoactive drugs alter behaviour at this level, often affecting many different types of neural receptors, cell types and synapses. Yet at the moment, candidate drugs are only tested on individual nerve cells, because it's proved difficult to keep larger pieces of brain tissue alive for more than a few hours.

The mini-brain, however, survives for weeks at a time. "We can even co-culture tissues from different parts of the brain on the same chip to examine the communication between them," says Pastrnak.

It consists of a glass chip containing tens of thousands of interconnected living brain cells, taken from rats or mice and suspended in a solution of artificial cerebral fluid. An array of 64 electrodes on the chip's surface monitors the overall electrical activity of the brain tissue, just like an electroencephalogram (EEG), to show the effect that drugs have on the tissue.

Tensor's electrodes maintain continuous contact with the cells but do not damage them. This is vital when repeating experiments, because you have to be sure you are always getting readings from the same groups of neurons.

Neurophysicist Peter Fromherz of the Max Planck Institute for Biochemistry in Martinsried, Germany, who has developed techniques to grow neurons on silicon, says the chips would be even more useful if they could record the activity of individual neurons. "The problem is that these electrodes are widely spaced, so you get little information about the neural circuits," he says.

But the 64 electrodes are enough to get useful EEG readings even if you can't tap into the electrical activity of single neurons, Fromherz says. And Tensor has also developed a way to produce the natural EEG rhythms, or brainwaves, in its chip. The rhythms continue even after the chemical that induces them has been washed off. Fromherz thinks that the chip will indeed provide a powerful new tool for testing the effect of drugs.

At next week's Chips to Hits conference in Philadelphia, Tensor Biosciences will announce that it has already used its chip to find a potential drug for anxiety that it believes will be more specific, less toxic and have fewer side effects than existing drugs.


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New Scientist issue: 19th October 2002

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Written by Duncan Graham-Rowe

thousands of interconnected living brain cells

how do they make a selection?
how do they know they hav not missed anything crucial?

a vibroslice is ~1/3 mm thick?

[blink]

?

Nanotechnology is the ability to control an artificial construction one atom at time, leading to machines the size of molecules. This relativistic perspective makes a living cell the size of a city block in relation to an ant, but even an ant can gather with other ants to find the sweet spot on the block and exploit that resource.

MEM's are not science fiction any longer and the obvious overlap into biological applications had better make everybody standup and take notice.

This is an example of the difference between a "Top-down versus a Bottom-up perspective. You are seeing this from the classic "Top-Down" one looking through the micropscope at the complexity from above but now change perspectives and find the tools and power to make this alternative perspective work.

Yes Caliban, and all others who read this realize that the Fantastic Voyage is underway.

Neuro-Chip from Infineon Can Read Your Mind - New Findings in Brain Research Expected

Munich, February 11, 2003 – Infineon Technologies announces a breakthrough development for neurological science by means of a biosensor chip. Researchers at Infineon and the Max Planck Institute managed to record and process the electrical signals from nerve cells, so-called neurons, as exactly as never before. The “Neuro-Chip” amplifies the signals and transfers them to a computer system for processing. This innovation is a promising development for researchers who expect to gain new insight into the neuron jungle that forms the human brain. Here, more than 100 billion nerve cells are continuously exchanging information. Knowledge of their principle of operation and interaction could be a first step toward solving diseases to the brain which are still incurable today

http://www.infineon....ss/302_042e.htm

Great Find BJ!

Fromhertz, the guy who lead the development of these chips, for a long time was trying to grow single neurons on single gates. Looks like he gave that up in favor of something much more like an array we use, but this thing has incredible resolution. I just sent a request for technical information and asked about a free sample My only worries are that these electrodes are so close together that there will be interference and I have nightmares about trying to sort through data from 16,000 channels! (we currently use 60)

Best, Ocsrazor

I'm going to use this post as a teaser for Sunday's chat.

These are the chips we currently use from Multi Channel Systems, also a German company (gotta love German precision engineering )

http://www.multichan...a-60/index.html

60 Channel Microelectrode Array by Multi Channel Systems of Germany

In this picture:
MEA 60 From Right to Left, increasing magnification of the array
Low magnification - the whole array 1mm x 1mm
Medium magnification - single electrode 10um diameter
High magnification - Fine structure of electrode

60 Channel Microelectrode Array by Multi Channel Systems of Germany

Life size picture of the whole dish. The array from the previous picture can be barely be seen as a set of gold points in the center of the dish. Neurons would be grown in the dish, attached by a biological adhesive. You can see the 60+4 (60 digital, 4 analog) arrangement of leads going into the array. The gold squares around the edge are the contact points for interfacing the dish to an amplifier.

Edited by ocsrazor, 12 February 2003 - 02:41 PM.

60 Channel Microelectrode Array by Multi Channel Systems of Germany

In this picture you have an open amplifier with a dish inserted. The lid is closed and the dish is locked into the amplifier. It is open in the center on the top and bottom for observation and care of the cells on the chip. There is a cable leading from the amplifier to a computer that receives the signals from the dish. Stimulation can also be done through all channels by a board that plugs into the amplifier.

Edited by ocsrazor, 12 February 2003 - 02:48 PM.

The Panasonic 64 channel multielectrode array (neurochip)

http://www.med64.com...d_medprobe.html

This article refers to an issue that is very relevant to all aspects of immortality, whether the solutions are transgenic or hypergenic. We are organic and regardless of the substrate we eventually develop as able to sustain our "lives" we must get there from here.

It is important to assess the validity and potential of the claims made in this issue of DNA computational ability because it defines the potential for us to upgrade what we are now, as well as from an understanding of what we are how to best interface our "intellect/identity" with augmentation devices that extend our ability and "reach" (physiologically, sensually, and comprehensively).

DNA is a computation medium and its potential by those that our enthralled with electronics is perhaps underestimated. The data as it is developed will speak for itself.

http://edition.cnn.c...g.ap/index.html
DNA basis for new generation of computers
Monday, August 18, 2003 Posted: 1506 GMT (11:06 PM HKT)

Milan Strojanovic recently published research describing a biological-based computer that can't lose a game of tic-tac-toe to man.

SAN FRANCISCO, California (AP) -- It almost sounds too fantastic to be true, but a growing amount of research supports the idea that DNA, the basic building block of life, could also be the basis of a staggeringly powerful new generation of computers.

If it happens, the revolution someday might be traced to the night a decade ago when University of Southern California computer scientist Leonard Adleman lay in bed reading James Watson's textbook "Molecular Biology of the Gene."

"This is amazing stuff," he said to his wife, and then a foggy notion robbed him of his sleep: Human cells and computers process and store information in much the same way.

Computers store data in strings made up of the numbers 0 and 1. Living things store information with molecules represented the letters A,T,C and G.

There were many more intriguing similarities, Adleman realized as he hopped out of bed. He began sketching the basics of DNA computing.

Those late-night scribbles have long since given way to hard science, backed by research grants from NASA, the Pentagon and other federal agencies. Now a handful of researchers around the world are creating tiny biology-based computers, hoping to harness the powers of life itself.

They call their creations "machines" and "devices." Really, they are nothing more than test tubes of DNA-laden water, and yet this liquid has been coaxed to crunch algorithms and spit out data.

The problems solved by DNA computers to date are rudimentary. Children could come up with the answers more quickly with a pencil and paper.

But the researchers hope to someday inject tiny computers into humans to zap viruses, fix good cells gone bad and otherwise keep us healthy.

They're also pursuing the idea that genetic material can self-replicate and grow into processors so powerful that they can handle problems too complex for silicon-based computers to solve.

Eventually, the scientists aim to create self-sustaining computers that can be used, for instance, on deep-space voyages, to monitor and maintain the health of humans on board.

DNA computing is born

What struck Adleman most that night he jumped out of bed was how a living enzyme "reads" DNA much the same way computer pioneer Alan Turing first contemplated in 1936 how a machine could read data.

"If you look inside the cell you find a bunch of amazing little tools," said Adleman, who made the first DNA-based computation in 1994. "The cell is a treasure chest."


MINI STORAGE

A single gram of dried DNA, about the size of a half-inch sugar cube, can hold as much information as a trillion compact discs.

Adleman used his computer to solve the classic "traveling salesman" mathematical problem -- how a salesman can visit a given number of cities without passing through any city twice -- by exploiting the predictability of how DNA interacts.

Adleman assigned each of seven cities a different strip of DNA, 20 molecules long, then dropped them into a stew of millions of more strips of DNA that naturally bonded with the "cities." That generated thousands of random paths, in much the same way that a computer can sift through random numbers to break a code.

From this hodgepodge of connected DNA, Adleman eventually extracted a satisfactory solution -- a strand that led directly from the first city to the last, without retracing any steps. DNA computing was born.

What these researchers are essentially trying to do is control, predict and understand life itself. So there's little wonder that their machines are decades away from being anything more than a neat laboratory trick.

Biologists are only now grasping the basics of how and why DNA unzips, recombines and sends and receives information. DNA is notoriously fragile and prone to transcription errors -- as the world's cancer rates prove.

These realizations and others have tempered initial expectations that DNA would ultimately replace silicon chips. Still, researchers in this field believe they remain on the vanguard of a computational revolution.

After all, a single gram of dried DNA, about the size of a half-inch sugar cube, can hold as much information as a trillion compact discs. Adelman senses that can be exploited somehow, some way.

"I'm just not sure how," he said.


Computers in a drop of water

One problem is that setting up DNA computers and extracting results from them can take days, sometimes weeks. Perhaps a bigger obstacle is controlling biological developments to generate accurate calculations. DNA doesn't always behave like it's expected to.

Columbia University researcher Milan Strojanovic, using NASA money, is developing a biology-based machine that doesn't need hands-on human help to compute.

"We want to use that technology for astronauts for health maintenance," said NASA scientist Paul Fung, who helps administer Strojanovic's grant as part of a $15 million program to develop biomechanical sensors for use in space travel.

Ehud Shapiro of Israel's Weizmann Institute of Science envisions programming tiny molecules with medical information and injecting them into people. He received a U.S. patent in 2001 for a "computer" within a single droplet of water that uses DNA molecules and enzymes as input, output, software and hardware.

This year, researchers in his lab added a power source to the device, capitalizing on the energy created when DNA molecules naturally break apart. In February, Guinness World Records Ltd. called the team's invention "the smallest biological computing device."

Shapiro also doubts genetics will supplant silicon, but remains optimistic.

"I think they will live together happily," he said, "and be used for different applications."

On Sunday, Strojanovic and a colleague published a paper in the journal Nature Biotechnology describing how they built a biological-based computer that can't lose a game of tic-tac-toe to man, and doesn't need any prompting from outside sources to compete.

"This is the kind of clever use of DNA computation," Adleman said, "that may eventually lead to practical applications."