Consciousness Blog 10 March 2013


Glial cells play a role in the formation and maintenance of the myelin sheath of axons, and have multiple involvments in the transmission of nervous impulses. A study published in the journal Cell Stem Cell, describes a type of glial cell known as astrocytes, larger and more complex in humans than in other species. Researchers transplanted human astrocytes into mice, which improved the speed of functioning of their axons.

Co-senior author of the study, University of Rochester Medical Center (URMC) neurologist Steven Goldman said: "This study indicates that glia are not only essential to neural transmission, but also suggest that the development of human cognition may reflect the evolution of human-specific glial form and function. We believe that this is the first demonstration that human glia have unique functional advantages. This finding also provides us with a fundamentally new model to investigate a range of diseases in which these cells may play a role."

The research team isolated human glial progenitors and transplanted them into the brains of neonatal mice. As the mice matured, the human glial cells took over from the mouse equivalents. Said Goldman: "The human glia cells essentially took over to the point where virtually all of the glial progenitor cells and a large proportion of the astrocytes in the mice were of human origin, and essentially developed and behaved as they would have in a person's brain."

The researchers found that the speed of neural transmission in the transplanted mice was faster than normally observed in mice, and more similar to that of human brain tissue. The mice had improved learning capability.

"The bottom line is that these mice demonstrated an increase in plasticity and learning within their existing neural networks, essentially changing their functional capabilities," said Goldman. "This tells us that human glia have a species-specific role in intellectual capability and cognitive processing. While we've suspected for a while that this might be the case, this is really the first proof of this point."

The researchers see a role for their chimerical mice in research into neurological disorders. Well and good, but perhaps more interesting for consciousness research is the idea that robotic brains (and eventually human brain clones) could be constructed from an assembly of biological and electronic neurological elements. All existing human-originated external control mechanisms are exclusively electro-mechanical, as far as we know, but it has always seemed likely that hybrid bio-electronic assemblies might have advantages.

If human proto-glial cells can grow and function in a different neural environment to the one they were 'designed' for, albeit another mammalian brain, a vista opens up of neural diy pick-and-mix 'brain' manufacture.

Of course, bio-electronic brain clones, to whatever partial degree they come to exist, are only a stepping-stone on the way to fully electronic brain clones in the cloud. However, they will continue to have their uses even if we end up living in the cloud ourselves. The robotic caretaker who looks after your physical holiday home for when you want to use it will have to do physical chores, feed the cats and pick roses for the dining-room, so he has to have a mixed bio-electronic-mechanical nature. It will be much easier for you to communicate with him if his sensory equipment mirrors your own.

Read more in Chapter Eleven of Agent Human by Michael Bell, The Future of Groups and Self-Awareness.


 

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