Relationship between resting cytosolic Ca2+ and responses induced byN-methyl-d-aspartate in hippocampal neurons

Abstract Cytosolic calcium concentrations ([Ca 2+ ] i ) in cultured hippocampal neurons from rat embryos were measured using fura-2. Neurons with higher resting [Ca 2+ ] i showed greater [Ca 2+ ] i responses to N -methyl- d -aspartate (NMDA) and K + depolarization. There was a strong relationship between resting [Ca 2+ ] i and the maximal changes in [Ca 2+ ] i (Δ[Ca 2+ ] i ), which fit the our proposed equation to describe this relationship.