How does xenon produce anaesthesia?

Since the discovery that the gas xenon can produce general anaesthesia without causing undesirable side effects, we have remained surprisingly ignorant of the molecular mechanisms underlying this clinical activity of an 'inert' gas. Although most general anaesthetics enhance the activity of inhibitory GABAA (γ-aminobutyric acid type-A) receptors,, we find that the effects of xenon on these receptors are negligible. Instead, xenon potently inhibits the excitatory NMDA (N-methyl-D-aspartate) receptor channels, which may account for many of xenon's attractive pharmacological properties.