Referenced in: none

Automatically associated channels: Kv2.1

Title: Xenon acts by inhibition of non-N-methyl-D-aspartate receptor-mediated glutamatergic neurotransmission in Caenorhabditis elegans.

Authors: Peter Nagele, Laura B Metz, C Michael Crowder

Journal, date & volume: Anesthesiology, 2005 Sep , 103, 508-13

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16129975

Abstract
Electrophysiologic experiments in rodents have found that nitrous oxide and xenon inhibit N-methyl-D-aspartate (NMDA)-type glutamate receptors. These findings led to the hypothesis that xenon and nitrous oxide along with ketamine form a class of anesthetics with the identical mechanism, NMDA receptor antagonism. Here, the authors ask in Caenorhabditis elegans whether xenon, like nitrous oxide, acts by a NMDA receptor-mediated mechanism.Xenon:oxygen mixtures were delivered into sealed chambers until the desired concentration was achieved. The effects of xenon on various behaviors were measured on wild-type and mutant C. elegans strains.With an EC50 of 15-20 vol% depending on behavioral endpoint, xenon altered C. elegans locomotion in a manner indistinguishable from that of mutants in glutamatergic transmission. Xenon reduced the frequency and duration of backward locomotion without altering its speed or other behaviors tested. Mutation of glr-1, encoding a non-NMDA glutamate receptor subunit, abolished the behavioral effects of xenon; however, mutation of nmr-1, which encodes the pore-forming subunit of an NMDA glutamate receptor previously shown to be required for nitrous oxide action, did not significantly alter xenon response. Transformation of the glr-1 mutant with the wild-type glr-1 gene partially restored xenon sensitivity, confirming that glr-1 was necessary for the full action of xenon.Xenon acts in C. elegans to alter locomotion through a mechanism requiring the non-NMDA glutamate receptor encoded by glr-1. Unlike for the action of nitrous oxide in C. elegans, the NMDA receptor encoded by nmr-1 is not essential for sensitivity to xenon.