Wednesday, March 23, 2011

Building a Neo-Nano-Neuro-Brain from Scratch


Human brains are amazing mental machines. As far as we know, there is nothing else quite like them in the universe. But we always wonder whether perhaps, we could build something just a bit better? Observe all the hoopla and expenditure over the past 60+ years in the field of "artificial intelligence." What a disappointment that has been so far.

It seems we may be taking the wrong approach to the problem. Why should we abandon the human brain -- the only working model of conscious intelligence that we know of -- and place all our hopes on digital silicon? Perhaps the human brain is not as intelligent as we thought -- at least human brains in academia, research, and research funding?

Here is an interesting twist on the conundrum: Why not design a neuronal scaffolding out of nanotubes made of germanium and silicon, then allow neurons to grow within the scaffolding? The neurons will naturally make networked connections with each other along the scaffold, but an added bonus may be the ability to interface the neurons with the silicon-germanium substrate of the scaffold itself.
Graduate students at the University of Wisconsin, Madison, led by Minrui Yu, have published an ACS Nano paper, "Semiconductor Nanomembrane Tubes: Three-Dimensional Confinement for Controlled Neurite Outgrowth," in which they show that they have been able to successfully coax nerve cell tendrils to grow through tiny tubes made of the semi-conductor materials silicon and germanium. While this ground-breaking research may not portend cyborgs or even human brains enmeshed with computer parts, it does open the door to the possibility of regenerating nerve cells damaged due to disease or injury.

Yu and his team, led by Justin Williams, a biomedical engineer, created tubes of varying sizes and shapes, small enough for a nerve cell to glam on to, but not so big that it could fit all the way inside. The tubes were then coated with nerve cells from mice and then watched to see how they would react. Instead of sitting idly, the nerve cells began to send tendrils through the tunnels, as if searching for a path to something or somewhere else. In some instances they actually followed the contours of the tubes, which means, in theory, that the nerves could be grown into structures. _PO
Indeed. The nerves could be grown into structures along prescribed pathways. But the possibility of a functional and powerful brain-machine interface is also being considered.
The hope of course, in this type of research, is that a way can be found to connect a computer of some sort to a group of nerve cells to reestablish communication that has been disrupted. The computer in this case could serve as a relay of sorts, allowing those who can no longer walk, for example, due to spinal injury or disease, regain their former abilities. In that regard, this particular research is even more revealing than it might at first seem, due to the fact that the tiny tubes that have been created, very closely resemble myelin, the outer insulating sheath that covers parts of normal nerve cells. _PO
This is the actual goal of the researchers in Wisconsin: to grow a nerve:computer interface. But emergent phenomena are likely to grow from the humble beginnings of such an approach. If one can design a scaffolding according to the most advanced brain imaging, seed it with the appropriate proto-cells, and nourish it into an intricate, functioning, autopoietic neural:nano hybrid network, what fascinating phenomena may manifest themselves along the way?

Cyborg or Grobyc? You be the judge.

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