Slow deactivation kinetics of NMDA receptors containing NR1 and NR2D subunits in rat cerebellar Purkinje cells

J Physiol. 2000 Jun 1;525 Pt 2(Pt 2):299-305. doi: 10.1111/j.1469-7793.2000.t01-1-00299.x.


We have examined the deactivation kinetics of native N-methyl-D-aspartate receptors (NMDARs) containing NR1 and NR2D subunits by patch-clamp recording from Purkinje cells in cerebellar slices from young rats. NMDAR-mediated whole-cell currents were elicited in response to bath application of 20 microM NMDA and 50 microM glycine. The NMDAR-mediated currents were small, with an average whole-cell conductance of approximately 750 pS. Following the rapid application of brief pulses (1-10 ms) of 1 mM glutamate to outside-out membrane patches, we observed a low-conductance type of single-channel activity which lasted up to 30 s after the removal of agonist. Analysis of individual channel openings revealed asymmetry of transitions between the main- and subconductance states - a characteristic of NR1/NR2D-containing NMDARs. The averaged macroscopic current exhibited a decay time course which was well described by a single exponential function with a time constant of approximately 3 s. We conclude that native NR1/NR2D-containing NMDARs, like their recombinant counterparts, display very slow deactivation kinetics. This feature should provide a means for identification of these receptors at synapses, and indicates that they do not contribute to the synaptic NMDAR currents so far described.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Glutamic Acid / pharmacology
  • In Vitro Techniques
  • Kinetics
  • Patch-Clamp Techniques
  • Purkinje Cells / drug effects
  • Purkinje Cells / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors*
  • Receptors, N-Methyl-D-Aspartate / chemistry*
  • Receptors, N-Methyl-D-Aspartate / metabolism


  • NR1 NMDA receptor
  • Receptors, N-Methyl-D-Aspartate
  • Glutamic Acid