In the article “Descending 5-Hydroxytryptamine Raphe Inputs Repress the Expression of Serotonergic Neurons and Slow the Maturation of Inhibitory Systems in Mouse Embryonic Spinal Cord,” by Pascal Branchereau, Jacqueline Chapron, and Pierre Meyrand, which appeared on pages 2598-2606 of the April 1, 2002 issue, mouse embryonic stages have been erroneously labeled because of confusion about the half-day mating period. Developmental stages were reported as being 1 d older than their actual age. Thus, E12.5, E14.5, and E18.5 should be labeled E11.5, E13.5, and E17.5.
