Vol. 181 No. 3, May 5, 2008. Pages 551–565.

In Fig. 2 D, the rise times for NMDA receptor-mediated miniature synaptic currents were plotted incorrectly. The correct values for the mean mEPSC rise time from baseline to peak should be 7.3 ± 0.3 ms and 8.5 ± 0.1 ms for WT and KO cultures, respectively. The interpretations of our overall findings and the conclusions presented in our original manuscript are not affected by this correction.