Correction: For the article “Maturation of Ribbon Synapses in Hair Cells Is Driven by Thyroid Hormone” by Gaston Sendin, Anna V. Bulankina, Dietmar Riedel, and Tobias Moser, which appeared on pages 3163–3173 of the March 21, 2007 issue, there are three corrections. (1) In Materials and Methods, Real-time RT-PCR, TaqMan Gene Expression Assays Mm01330351_mH, Mm00464451_m1 and Mm01336180_m1 were used to amplify cDNAs for SNAP23, Bassoon, and SNAP25 (instead of for Bassoon, SNAP25, and SNAP23, as erroneously stated in the original text). (2) In Figure 3A, the first SNAP25 label should read SNAP23; currently and erroneously there are two labels reading SNAP25. (3) T.M. acknowledges financial support by the German Ministry for Education and Research via the Bernstein Center for Computational Neuroscience Gödottingen under Grant 01GQ0432.