Traveling Through Brain Cells

Researching brain cells the team from the Humboldt University in Germany and the Erasmus Medical Center in the Netherlands have made an interesting medical discovery. It appears that there could be enough computing ability in just one brain cell to allow humans and animals to feel, a study suggests. The research, conducted with rodents and published in the Dec. 20 issue of Nature, could rewrite the textbooks on just how important individual brain cells or cell clusters are to the working mind.

The Dutch and German study found that stimulating just one rat neuron could deliver the sensation of touch. Before these insights, "The thinking was that very large ensembles of neurons [brain cells] had to be activated at some point for the animal to feel or perceive" a stimulus, explained the senior researcher of two of the studies, Karel Svoboda, a group leader at the Howard Hughes Medical Institute in Ashburn, Va.

"But it turns out that a remarkably small number -- on the order of 50 or so activated neurons -- is sufficient to drive reliable behaviors," said Svoboda, who is also associated with the Cold Spring Harbor Laboratory, in New York.
A second research project from the US suggests the computational ability of the brain cell could be even more complex, with different synapses - the many junctions between neurons and other nerve cells - able to act independently from those found elsewhere on the same cell.
This could mean that, within a single neuron, different synapses could be storing or processing completely different bits of information. Dr Douglas Armstrong, the deputy director of the Edinburgh Centre for Bioinformatics, said the research did not mean all neurons had an individual role to play but that, in some instances, they might be capable of working alone with measurable results. "The fact that a single cell can influence behavior in the cortex is fascinating," said neuroscientist Paul Sanberg, director of the Center for Excellence for Aging and Brain Repair at the University of South Florida, Tampa. The new findings are "allowing us to answer questions about how the brain controls behavior at the cellular level," added Sanberg, who was not involved in the studies.
He said: "The generally accepted model was that networks or arrays make decisions and that the influence of a single neuron is smaller - but this work and other recent studies support a more important role for the individual neuron.
"These studies drive down the level at which relevant computation is happening in the brain."