Neuroprotective properties of xenon and helium in an in vitro model of traumatic brain injury: one small step or one big jump?

Traumatic brain injury (TBI) is a significant source of morbidity and mortality throughout the world. Accordingly, an effective treatment would fill a major clinical need. Promising strategies to minimize secondary brain injury after TBI have met with very limited clinical success. To date, all compounds investigated produced adverse side effects and provided intrinsic neurotoxicity at neuroprotective and therapeutic concentrations, or they were ineffective when translated into the clinical setting. The “inert” gas xenon is an antagonist of the N-methyl-D-aspartate-type glutamate receptor but also blocks AMPA and kainate receptors in cortical neurons. On this basis, xenon seems to be rather nonspecific as a channel blocker, and this may contribute to its analgesic and anesthetic potency. In addition to having anesthetic and analgesic effects, xenon has been shown to exert substantial organoprotective properties, especially in the brain and the heart, and to be an effective neuroprotectant in a variety of in vitro and in vivo models of neuronal injury.