Changes in voltage dependence of NMDA currents during development.

N-Methyl-D-aspartate (NMDA), applied by superfusion to hippocampal slices evokes comparable peak inward currents in CA3 pyramidal cells of adult and 0-10 day-old rats. However, NMDA current-voltage plots from immature neurones do not consistently show the region of negative slope conductance characteristic of adult. Therefore at a critical stage of development, NMDA activation may elicit substantial inward currents and Ca2+ influx at resting membrane potential.