Author name: Matthew T. Dearing

The first test of an actual silicon device will soon be performed to help restore function to a slice of tissue from a rat’s damaged hippocampus!

This news item has been splashing into headlines all over the world yesterday and today, so we’re trying to keep track of the journalists’ take on the issue. As we keep finding more links, we’ll update this post.

Theodore Berger and his team at the University of Southern California have been working for years to develop mathematical models that represent the appropriate computations performed in the hippocampus of the brain, the area of your brain which is widely accepted as a major storage container and processor of memories. These models would then guide the design and fabrication of an actual silicon chip to be directly integrated with the brain tissue.

However, fully understanding the mechanisms of specific computations in our brain is still beyond scientists’ desperate grasp, so Berger’s team listened to neural activity and attempted to encode what they saw it into silicon.

To accomplish this, a silicon chip is fabricated with tiny electrodes–basically little metal pads and wires–that sit nearby active, non-damaged neurons and receive their electrical signals that are supposed to be providing “input” to damaged neurons. These captured input signals are transmitted by the embedded silicon chip to another chip sitting outside the brain. The external chip is like a mini-computer that processes these electrical signals according to Berger’s model of how the hippocampus is supposed to function. Based on this on-chip processing, it finally sends new electrical signals back down to the non-damaged neurons.

These computer-generated electrical signals are meant to exactly replace the electrical signals that would have resulted from the neurons receiving the original input, but couldn’t do so because they were damaged in some way.

Important note: This prototype brain prosthetic has been specifically programmed to function in a certain way–a way that neurons in a rat’s hippocampus presumably communicate. A successful test of this device will show that if the hippocampus is “turned off” in an animal and the device “turned on”, then normal brain activity resumes.

This would be a great step forward in developing technologies that replace damaged function in our nervous systems. Forgot where your keys are? Can’t find where you placed your presentation material due to your boss in exactly 1.2 minutes? No problem, just don’t forget to turn on your “memory chip”.

Maybe that’s where we are headed, but not by just copying our neural activity from when we were still healthy. One of the articles below mentions the concern that since what we consider to be our “self”, likely has a great deal to do with our memories, then a prosthetic device that has strict and static on-board processing rules, might somehow alter who we really “are”.

Certainly, more must be understood about how our brain functions in general, but this upcoming test is still very exciting!

[ Read the article from the New Scientist ]

[ Read the article from Ananova ]

[ Read the article from MSNBC.com ]

[ Read the article from BBC News ]

[ Read the article from the Guardian ]

Now Serving Brains on a Chip!

Infineon Technologies, a tech company in Munich, Germany, recently announced that it has developed a silicon device that is capable of recording electrical signals from brain slices. They call it the “Neuro-Chip” and it contains over 16,000 electrodes, spaced every 8 microns, and records the cells’ activity 2,000 times per second.

The basic design of recording the electrical activity of a neuron sitting on a silicon wafer has certainly been done before, primarily in the world of academia at many institutions [University of Illinois, Urbana-Champaign, Cornell University, University of Michigan, and others]. However, this is one of the first examples of a research company claiming significant progress toward a commercializable project for scientists to purchase and use in their research. This is certainly an exciting development!

There is an important idea to keep in mind with how useful the information pumped out of this little neurodevice will be. Infineon’s chip has tons of electrodes spread out over the silicon surface recording the electrical activity en masse. The recording capability is presumably quite sensitive and capable of pulling out a great deal of information.

Scientists will have to dig in deep, though, to figure out exactly how to relate this sort of collective information to how the neuron network actually functions. It will likely be found that even more specific electrical recordings from each individual neuron is required to gain any insight into how the neurons work together.

[Read an article from Australian Broadcasting Corporation News Online]

[Read an article from Electronic Business Online]

[Visit the company website]

The pounding, the throbbing, the sensitive scalp, the agony! What if you could push a button and zap it all away?

Extreme headaches (and we’re talking about those very rare extreme cases) are first attacked with drugs and more drugs. But, if the pulsating brain tissue isn’t tamed, then some doctors are trying to directly stimulate nerves in the brain with a little, directed electrical shock.

Our body senses pain when certain nerves become active and send pulses of electricity to our brain to tell it something is wrong in the nerve’s neck of the woods. If we aren’t able to repair the problem causing the “pain receptor” nerves to be quiet, then another approach is to block or mask its electrical activity.

Implanting an electrode near an over-active nerve and passing electricity to directly stimulate the nerve has been seen to block the pain messages sent to the brain. The fact that this method has had some initial experimental success is very interesting because you might first think that this stimulation would enhance the pain signals. Somehow the additional electrical activity around the nerve acts to confuse the signals to the brain, and makes that throbbing feeling vanish.

[ Read a related Neuron News article ]

[ Read the article from Yahoo! News/AP Health ]

[ Read the news release from Rush Medical Center ]