What was discovered?

Astrocytes were thought to feed and support  the brain's nerve cells, but now a new important role in learning and memory has been found.

In learning, nerve connections are strengthened or new connections are made.  At the connections between two nerve cells there is a tiny gap called a synapse.  Molecules cross this gap, passing information to the next nerve cell - learning occurs as these connections are strengthened by repeating the action, so that the information passes more easily.

The molecule carrying information acoss the synapse is called glutamate. Strengthened synapses release more glutamate.

Astrocytes cooperate with the nerve cells receiving the information by way of glutamate, and can take away the glutamate from the synapses - of course if too much glutamate is taken away, that is not good for learning!