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Explore the brain's hidden frontiers

The brain isn't just about neurons. Mark Ellisman, founder and director of the National Center for Microscopy and Imaging Research, says attention must also be paid to the glial cells, which actually outnumber neurons in the cerebral cortex.

Glial cells help support the neurons, conduct chemical housekeeping functions — and play a helping role in the transmission of signals from one neuron to another. In the video above, which was created for the Whole Brain Catalog, a virtual camera gradually focuses in on a glial cell that guides two neurons to make a synaptic connection.

"They're looking to hook up, looking for that hot axon in the street," Ellisman joked today during an afternoon session at the "Open Questions in Neuroscience" symposium in Seattle.

In this scenario, the glial cell acts as a matchmaker to facilitate the construction of circuitry inside our head — for example, during the learning process. Ellisman said the protein that glial cells sprinkle onto neurons during this process, known as thrombospondin, is also linked to the wound-healing process. Which led to an observation with philosophical as well as biochemical implications.

"You can think of the injuries of experience as the wounds the brain knows how to heal," he said.


Stay tuned for more from the "Open Questions in Neuroscience" symposium, sponsored by the Allen Institute for Brain Science at the Experience Music Project and Science Fiction Museum. Join the Cosmic Log corps by signing up as my Facebook friend or hooking up via Twitter. And if you really want to be friendly, ask me about "The Case for Pluto."