Mechanism of antiseizure effect of isoflurane in the immature rat hippocampus.

The volatile anesthetic isoflurane is often used in children in the management of refractory status epilepticus. However the mechanism of anticonvulsant action of isoflurane during early brain development is not clear. In this study we explore the role of excitatory and inhibitory conductances in antiseizure effect of isoflurane using combination of whole-cell patch-clamp and extracellular field potential recording techniques on two models of epilepsy in a hippocampal slice preparation from immature rat. Our data demonstrated that decreasing of excitatory synaptic transmission does not account for antiseizure effect of this volatile anesthetic agent. Isoflurane decreases the synchronization of neuronal activity mainly through the enhancing of GABAergic inhibition by influencing both phasic and tonic chloride conductances.