HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 543/1/23    most recent 2002.020321v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bai, D. Articles by Roder, J. C. Search for Related Content PubMed PubMed Citation Articles by Bai, D. Articles by Roder, J. C.

Non-ionotropic cross-talk between AMPA and NMDA receptors in rodent hippocampal neurones

Donglin Bai*, Robert U. Muller†‡ and John C. Roder*

Many fast excitatory synapses in the hippocampus are enriched with both AMPARs (-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate receptors) and NMDARs (N-methyl-D-aspartate receptors). Their proximity allows them to be activated simultaneously by the same neurotransmitter, L-glutamate. Activation of AMPARs leads to influx of sodium and calcium ions, which can increase or decrease NMDAR activity through sodium concentration-dependent cascades or a calcium-calmodulin-dependent inactivation process, respectively. Here we provide evidence that the activation of AMPARs inhibits NMDARs through a non-ionotropic mechanism. NMDA-induced current in isolated rat CA1 hippocampal cells and nucleated patches of cultured mouse hippocampal neurones decreased when AMPARs were activated. Conversely, when AMPARs were blocked, the NMDA component of glutamate-induced current increased. The inhibitory action of AMPAR activation on NMDAR-mediated current depends upon the open state of AMPA channels and rapidly diminishes after deactivation of AMPARs. The inhibitory action was independent of membrane voltage, univalent cation fluxes and calcium influx. The AMPA-NMDA cross-inhibition also occurred in evoked synaptic current in CA1 neurones from intact mouse hippocampal slices. This cross-talk may play a role in preventing overexcitation during bursting activities in the hippocampus.

This article has been cited by other articles:

				M. E. Pamenter, D. S.-H. Shin, and L. T. Buck AMPA receptors undergo channel arrest in the anoxic turtle cortex Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R606 - R613. [Abstract] [Full Text] [PDF]