Correction: In the article “Contribution of Subsaturating GABA Concentrations to IPSCs in Cultured Hippocampal Neurons” by M. W. Hill, P. A. Reddy, D. F. Covey, and S. M. Rothman, which appeared on pages 5103–5111 of the July 15, 1998 issue, the Hill coefficients mentioned in the legends for Figures 2 and 7 and in the text on page 5107, second column, should all be dimensionless.
