Ce. Jahr et Cf. Stevens, CALCIUM PERMEABILITY OF THE N-METHYL-D-ASPARTATE RECEPTOR-CHANNEL IN HIPPOCAMPAL-NEURONS IN CULTURE, Proceedings of the National Academy of Sciences of the United Statesof America, 90(24), 1993, pp. 11573-11577
We have developed a quantitative description for calcium permeability
of the N-methyl-D-aspartate receptor channel to permit predictions of
the reversal potential and calcium influx at different voltages for di
fferent extracellular calcium concentrations. Increasing the external
calcium concentration markedly shifted the reversal potential to posit
ive values and simultaneously decreased the single-channel conductance
at potentials negative to the reversal potential. Very simple quantit
ative descriptions of calcium permeation and channel block by calcium
ions accurately characterize our data and permit the prediction of rev
ersal potentials and magnitudes of calcium influx for a wide range of
conditions.