Figure 1.

Current–voltage relationship of wild-type and mutant NMDA receptors depends on extracellular calcium concentration. (A) Wild-type channels typically show reduced amplitude of whole cell response in high external calcium concentrations. Responses obtained in 0.1 mM calcium are represented by triangles and circles represent responses in 10 mM calcium. (B) Representative current–voltage relationship of mutant channels. Circles represent data from whole cells in 0.1 mM calcium and triangles from cells in 10 mM calcium. In both wild-type and mutant increasing extracellular calcium concentrations lead to a shift in the reversal potential toward more positive potentials.