A role for astrocytes in learning and memory?

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New research published today in the prestigious journal Nature sheds further light on how memories are formed in the brain.

Memories are formed through changes in the strength of individual synaptic connections between nerve cells. However, a large proportion of brain cells belong to glia which, unlike nerve cells, do not make synapses, are not electrically active and until recently have been associated with exclusively supporting roles.

Researchers from the Institute Department of Clinical & Experimental Epilepsy (in collaboration with colleagues in INSERM U 862 at the University of Bordeaux) have found that individual star-shaped glial cells called astrocytes release a specific signalling molecule, called D-serine, which is essential for triggering the memory trace machinery in active synapses nearby.

Astrocytes, once thought little more than passive, structurally supportive brain cells, are increasingly recognized as having a range of important properties and functions, such as the ability to release chemical messengers and signal to other cells. This study helps to add another potential function to that list.

Dmitri Rusakov, who led the research at the Institute said: “This finding establishes a previously unknown role of glia in basic functions of the human brain identifying a yet unexplored target area for therapeutic intervention.”

Reference >> Christian Henneberger, Thomas Papouin, Stéphane H. R. Oliet and Dmitri A. Rusakov (2010) Long-term potentiation depends on release of D-serine from astrocytes. Nature ( doi:10.1038/nature08673).