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Nerve Cells Successfully Grown on Silicon
crabpeople writes "Researchers at the University of Calgary have found that nerve cells grown on a microchip can learn and memorize information which can be communicated to the brain. 'We discovered that when we used the chip to stimulate the neurons, their synaptic strength was enhanced,' said Naweed Syed, a neurobiologist at the University of Calgary's faculty of medicine."
But what's the size of a neuron vs the size of a transistor in a 65nm process CPU?
-- *My* journal is more interesting than *yours*...
But this is very exciting. The idea that we could grow neurons on silicon is one of those big steps that looks to lead us into the Johnny Mnemonic world that Gibson was talking about just a couple stories prior to this one.
There is a song that says, "It only takes a spark to get a fire going". So too is it true that it only takes a couple neurons to start synapsing. As these true neural webs become more complicated, it would be interesting to see if any kind of emergent behavior was evident.
Also, with the current political and scientific climate as it is, this could be the first step to replicating a nervous system without having to rely on fetuses for stem cells. It requires no human cloning and holds immense promise.
It would definitely be cool to have a couple of these chips implanted to enhance the base memory that we are kitted with at birth, that's for sure!
I have been pwned because my
I thought the Pine Lab at Caltech had done this several years ago. Neurochip Project
Not making faster Pentiums or Athlons. Sorry. Most of that magic has already been woven. Who out there is qualified to make systems level designs and decisions about bio computer systems? Think about the type of knowledge it must take about physics, electrical and computer engineering, as well as biological knowledge.
What type of magnetic and power restrictions will there be? Reliability? What type of optimizations will exist? Interfaces? Flexibility?
We're still quite far away from having things like this be applicable to modern day but think about when you too can say, "I know Kung Fu"!
Researchers at the University of Calgary have found that nerve cells grown on a microchip can learn and memorize information which can be communicated to the brain.
While the article mentions this in the introduction, it doesn't mention this happening at all in the research. It talks about neurons communicating with each other. This is a long way from connecting this chip into a living brain in an animal that can still function.
While I agree that this is a fascinating article, we should make sure not to sensationalize it too much. Making chips that interface with actual brains in actual animals, even if they are snails, is still a long way off.
"Flying is the art of throwing yourself at the ground and missing." - Douglas Adams
a.k.a Neal Stephenson and his uncle.
Chip embedded in politician's brain after a stroke - he goes on to be president.... v. spooky.
I would love to see alzheimer's patients helped with this. If it's a genetic disease, I'm up the creek and dropped me paddle a while back.
- Lnr
Imagine a U.S. President that is simply a marionette made of organic plasma being controlled and manipulated by puppeteers and handlers behind the curtain - stringlessly AND wirelessly.
Alan Cooper, author of "The Inmates are Running the Asylum" and other texts put it this way:
Q: What do you get when you cross a camera and a computer?
A: A computer.
His point is that from an interface and place-in-the-world point of view, most products that have been digitally enhanced tend to remain closer to their technology roots than their analog counterparts (with all of the usability, and I would say ethical, challenges inherient in a technologist-driven system).
That said, this is pretty frickin' cool, but the double-edged sword presented by this innovation seems both particularly sharp and far reaching. I really hope we get this one right.
"Why can't you use your powers for Good?"
Neurons are much larger than transistors, but the two aren't really comparable. The main body of a neuron is usually around 25 microns (25000 nm) in diameter and runs at a clockspeed only in the kilohertz max.
A neuron is much more than a transistor-like switch. On the one side of the neuron's central body is a set of dendrites that connect to and gather input from other neurons. The average neuron might have a thousand of these dendrites.
The synapse at the end of each dendrite acts like part of a multiply-accumulate term -- taking the signal from an other neuron, multiplying it by a numerical coefficient and summing it into the total excitation level of the neuron's body. I suspect that the precision of this multiply -accumulate process is fairly low -- perhaps 8 to 16 bits.
Next, the body of the neuron has a long axon extending from it that sends the output of the neuron to other neurons (connecting to the dendrites of other neurons). This axon can be quite long, millimeters, even inches, in length. Thus, the axon is like an off-chip line driver with the potential to have a very high fanout (of a 1000 or more). (On a modern microchip, these off-chip connections are driven by much larger transistors than the small 65 nm ones used in computation).
Third, a neuron is not a static multiply-accumulate system. The coefficients on each synapse change in response to long-term adaptive processes. This process is computationally complex and includes cross-correlation of inputs between synapses and processing of other chemical signals in the brain. Cross-correlation alone could require the equivalent of several kilobytes to several megabyts of RAM. (We won't even get into the adaptive processes that include physical growth and removal of dendrites as this has no easy analog in hardware)
In summary, a neuron is more than a transistor-like switch. Its a free-running 1000 register multiply-accumulator with an off-chip line driver and a statistical processing engine that updates the coefficients on each of the multiply-accumulate terms. Thus, emulating a single neuron would require hundreds of thouands to millions of transistors.
Two wrongs don't make a right, but three lefts do.
Or, for a more software interpretation, it's a function that takes a bunch of boolean parameters and returns a boolean. Anyone who's ever done any programmation or computer architecture should see why you can easily process anything with this.
This axon can be quite long, millimeters, even inches, in length.
Acutally, it can be over a meter in length (spinal cord to calf is one axone). Try that with a transistor
Ask 8 slackers a question, get 10 awnsers (a citation, but I can't remember from who)
Who'll be the first to upload a linux distro into the brain of an actual pinguin.
Or, for a more software interpretation, it's a function that takes a bunch of boolean parameters and returns a boolean. Anyone who's ever done any programmation or computer architecture should see why you can easily process anything with this.
Excellent point. You are right about the computational flexibility of neurons. They can represent a wide range of logical functions, although I believe that the single neuron is incapable of doing an XOR.
But a neuron is more that a Boolean circuit. Although a neuron seems like a two-state device (its either quiesent or its firing), it is more of an N-state analog device in which the pulse-rate encodes a numerical quantity (probably the equivalent of an 8 to 16 bit floating point number). That is why the dendrite field is like a giant numerical multiply-accumulate.
Two wrongs don't make a right, but three lefts do.