A quantitative description of NMDA receptor-channel kinetic behavior

A quantitative description of NMDA receptor-channel kinetic behavior.

Currents evoked in neurons of the vertebrate CNS by the glutamate agonist N-methyl-D-aspartate (NMDA) exhibit a marked voltage dependence in the presence of extracellular Mg. At the single-channel level, the addition of external Mg alters single-channel openings from long-lived events to many very short events grouped into bursts of openings. These bursts apparently result from short interrupti...

NMDA channel behavior depends on agonist affinity.

We have compared the kinetic properties of NMDA receptor channels activated by exogenous agonists with those activated synaptically. Short (4 msec) applications of L-glutamate to outside-out patches from hippocampal neurons evoked currents that decayed with a double exponential time course that was controlled by both the unbinding rate of agonist and receptor desensitization. Lower-affinity ago...

Quantitative physiological characterization of a quinoxalinedione non-NMDA receptor antagonist.

The effects of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, or FG 9065) on excitatory amino acid responses in cultured neurons from rat hippocampus were studied using tight-seal whole-cell recording techniques. CNQX reduced the magnitude of peak inward currents produced by exogenously applied kainate, quisqualate, and N-methyl-D-aspartate (NMDA) with Ki's of 2.5, 3.5, and 96 microM, respectively...

A Quantitative Description of KcsA Gating II: Single-Channel Currents

The kinetic transitions of proton-activated WT KcsA and the noninactivating E71A mutant were studied at the single-channel level in purified, liposome-reconstituted preparations. Single-channel currents were recorded using patch-clamp techniques under nonstationary and steady-state conditions. Maximum-likelihood analyses reveal that the key influence of acidic pH is to increase the frequency of...

homology modeling of human nmda receptor and studies of the channel symmetry using brownian dynamics simulation