Calcium-dependent inactivation of heteromeric NMDA receptor-channels expressed in human embryonic kidney cells.

Academic Article

Abstract

  • 1. Whole-cell current through heteromeric NR1-NR2A and NR1-NR2B subunit combinations of NMDA channels transiently expressed in human embryonic kidney cells (HEK 293) were studied using the patch-clamp technique. 2. With 4 mM Mg-ATP in the internal pipette solution, the responses of cells expressing NR1-NR2A channels to glutamate application gradually decreased, reaching 50% of control during the first 20 min of recording. This process was accompanied by acceleration of desensitization. 3. Conditioning (5-15 s) applications of glutamate (100 microM) induced a transient inactivation of NR1-NR2A and NR1-NR2B channels (20-40%) with a slow time course of recovery (tau r = 10-60 s). Both the degree of inactivation and the time constant of recovery increased with the duration of conditioning applications of glutamate, and with an elevation of Ca2+ in the external solution. 4. These results show that both NR1-NR2A and NR1-NR2B recombinant NMDA receptor-channels expressed in HEK 293 cells can be transiently inhibited by Ca2+ ions in a similar way to that described for hippocampal neurones.
  • Keywords

  • Calcium, Cell Line, Glutamic Acid, Humans, Ion Channels, Kidney, Patch-Clamp Techniques, Receptors, N-Methyl-D-Aspartate, Recombinant Proteins
  • Digital Object Identifier (doi)

    Author List

  • Medina I; Filippova N; Charton G; Rougeole S; Ben-Ari Y; Khrestchatisky M; Bregestovski P
  • Start Page

  • 567
  • End Page

  • 573
  • Volume

  • 482 ( Pt 3)