Erratum

In the article “Glutamate Released from Glial Cells Synchronizes Neuronal Activity in the Hippocampus,” by Maria Cecilia Angulo, AndreïS. Kozlov, Serge Charpak, and Etienne Audinat, which appeared on pages 6920-6927 of the August 4, 2004 issue, there is an error in the figure citations in Results. On page 6922, the first complete sentence should read as follows: “However, current frequency could be markedly increased during pharmacological manipulations (see below), and in these conditions, the average amplitude of the currents showed the voltage-dependent block by extracellular magnesium ions expected for NMDA receptors (see Fig. 5B, inset).