The bars of the bar graph in Figure 2C in the article “Genetic and Physiological Evidence That Oligodendrocyte Gap Junctions Contribute to Spatial Buffering of Potassium Released during Neuronal Activity” by Daniela M. Menichella, Marta Majdan, Rajeshwar Awatramani, Daniel A. Goodenough, Erich Sirkowski, Steven S. Scherer, and David L. Paul, which appears on pages 10984–10991 of the October 25, 2006 issue, were switched. The “mean vacuolated area” bar contains the “# myelinated axons” data and vice versa.