Methods for Defining the Neuroprotective Properties of Xenon

Neurocognitive Effects of Fetal Exposure to Anesthesia

Surgery during pregnancy occurs when maternal or fetal needs outweigh the status quo, yet much uncertainty remains regarding the effects of anesthesia and surgery on fetal neurodevelopment. This article will review common maternal and fetal indications for invasive procedures, along with contemporary research on fetal neurodevelopment following anesthesia and surgery, focusing on future areas of investigation.

Efficacy of xenon anesthesia in preventing postoperative cognitive dysfunction after cardiac and major non-cardiac surgeries in elderly patients: a topical review

Elderly patients undergoing major cardiac and non-cardiac surgeries have a high propensity (up to 40–60%) of developing postoperative cognitive dysfunction, which are caused by patient’s factors, type of surgery, intraoperative and postoperative factors. All these pose a challenge to the clinicians. The noble gas xenon does not undergo metabolism or any kind of biotransformation in the body owing to its inert nature. Xenon confers excellent hemodynamic stability and provides excellent recovery at the end of surgery. This topical review discusses advantages of xenon anesthesia in elderly patients undergoing major cardiac and non-cardiac surgeries and whether it is worth using a costly anesthetic in elderly patients for preventing postoperative cognitive dysfunction.

Xenon modulates the GABA and glutamate responses at genuine synaptic levels in rat spinal neurons

Effects of xenon (Xe) on whole-cell currents induced by glutamate (Glu), its three ionotropic subtypes, and GABA, as well as on the fast synaptic glutamatergic and GABAergic transmissions, were studied in the mechanically dissociated "synapse bouton preparation" of rat spinal sacral dorsal commissural nucleus (SDCN) neurons. This technique evaluates pure single or multi-synapse responses from native functional nerve endings and enables us to quantify how Xe influences pre- and postsynaptic transmissions accurately. Effects of Xe on glutamate (Glu)-, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-, kainate (KA)- and N-methyl-d-aspartate (NMDA)- and GABA_A receptor-mediated whole-cell currents were investigated by the conventional whole-cell patch configuration. Excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) were measured as spontaneous (s) and evoked (e) EPSCs and IPSCs. Evoked synaptic currents were elicited by paired-pulse focal electric stimulation. Xe decreased Glu, AMPA, KA, and NMDA receptor-mediated whole-cell currents but did not change GABA_A receptor-mediated whole-cell currents. Xe decreased the frequency and amplitude but did not affect the 1/e decay time of the glutamatergic sEPSCs. Xe decreased the frequency without affecting the amplitude and 1/e decay time of GABAergic sIPSCs. Xe decreased the amplitude and increased the failure rate (Rf) and paired-pulse ratio (PPR) without altering the 1/e decay time of both eEPSC and eIPSC, suggesting that Xe acts on the presynaptic side of the synapse. The presynaptic inhibition was greater in eEPSCs than in eIPSCs. We conclude that Xe decreases glutamatergic and GABAergic spontaneous and evoked transmissions at the presynaptic level. The glutamatergic presynaptic responses are the main target of anesthesia-induced neuronal responses. In contrast, GABAergic responses minimally contribute to Xe anesthesia.