Neural Networking Nanotubes - (interesting news)

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Neural Networking Nanotubes

http://www.medicalnewstoday.com/medicalnews.php?newsid=56453

New implantable biomedical devices that can act as artificial nerve

cells, control severe pain, or allow otherwise paralyzed muscles to

be moved might one day be possible thanks to developments in

materials science. Writing today in Advanced Materials,

Kotov of the University of Michigan, USA, and colleagues describe

how they have used hollow, submicroscopic strands of carbon, carbon

nanotubes, to connect an integrated circuit to nerve cells. The new

technology offers the possibility of building an interface between

biology and electronics.

Kotov and colleagues at Oklahoma State University and the University

of Texas Medical Branch have explored the properties of single-

walled nanotubes (SWNTs) with a view to developing these materials

as biologically compatible components of medical devices, sensors,

and prosthetics. SWNTs are formed from carbon atoms by various

techniques including deposition and resemble a rolled up sheet of

chicken wire, but on a tiny scale. They are usually just a few

nanometers across and up to several micrometers in length.

The researchers built up layers of their SWNTs to produce a film

that is electrically conducting even at a thickness of just a few

nanometers. They next grew neuron precursor cells on this film.

These precursor cells successfully differentiated into highly

branched neurons. A voltage could then be applied, lateral to the

SWNT film layer, and a so-called whole cell patch clamp used to

measure any electrical effect on the nerve cells. When a lateral

voltage is applied, a relatively large current is carried along the

surface but only a very small current, in the region of billionths

of an amp, is passed across the film to the nerve cells. The net

effect is a kind of reverse amplification of the applied voltage

that stimulates the nerve cells without damaging them.

Kotov and his colleagues report that such devices might find use in

pain management, for instance, where nerve cells involved in the

pain response might be controlled by reducing the activity of those

cells. An analogous device might be used conversely to stimulate

failed motor neurons, nerve cells that control muscle contraction.

The researchers also suggest that stimulation could be applied to

heart muscle cells to stimulate the heart.

They caution that a great deal of work is yet to be carried out

before such devices become available to the medical profession.