Head Lines; August/September 2007; Scientific American Mind; by Mason Inman, Corey Binns, Karen A. Frenkel, Melinda Wenner, Nicole Branan, Dinsa Sachan, Maia Szalavitz, Graciela Flores, Siri Carpenter; 6 Page(s)

Our brain cells are chattier than previously thought, according to a new study. Cells in white matter, once believed to passively relay information between neurons, were found to eavesdrop on the messages they carried and to receive chemical signals from other cells.

Until now, researchers believed our brain had a basic division of labor between gray matter and white matter. In gray matter, neurons form dense networks and process information by sending signals along finger-like projections called axons. White matter was thought to play a supporting role by producing a white protein called myelin that coats the axons and allows them to send signals more quickly.