Desflurane improves the recovery of the evoked postsynaptic population spike from CA1 pyramidal cells after hypoxia in rat hippocampal slices

Desflurane is a volatile anesthetic that allows rapid induction and emergence, reduces cerebral metabolism, and enhances tissue perfusion. We studied the effect of treatment with 4%, 6%, and 12% desflurane on hypoxic neuronal damage by comparing the size of the postsynaptic evoked population spike recorded from the cornu ammonis 1 (CA1) pyramidal cell layer of rat hippocampal slices before and 2 hours after a hypoxic insult. When the tissue was treated with 6% desflurane before, during, and after 3.5 minutes of hypoxia, recovery was significantly better in slices exposed to desflurane (37% ± 9%) compared with untreated hypoxic slices (15% ± 5%). A lower (4%) or higher (12%) concentration of desflurane did not significantly improve recovery after 3.5 minutes of hypoxia. In the period before hypoxia, 12% and 6% desflurane significantly increased the latency and decreased the amplitude of the postsynaptic population spike; 4% desflurane had a similar but nonsignificant effect on latency and amplitude. We conclude that 6% desflurane, a clinically useful concentration (1 minimal alveolar concentration), improved the recovery of postsynaptic evoked responses in rat hippocampal slices after 3.5 minutes of hypoxia. In vivo studies must be conducted to assess the potential clinical significance of 6% desflurane's neuroprotective activity.