Multiple Mechanisms Underlying the Neuroprotective Effects of Antiepileptic Drugs Against In Vitro Ischemia

Abstract
Background and Purpose— The possible neuroprotective effects of classic and new antiepileptic drugs on the electrophysiological changes induced by in vitro ischemia on striatal neurons were investigated. In particular, the aim of the study was to correlate the putative neuroprotective effects with the action of these drugs on fast sodium (Na+) and high-voltage–activated (HVA) calcium (Ca2+) currents. Methods— Extracellular field potentials were recorded from rat corticostriatal brain-slice preparations. In vitro ischemia was delivered by switching to an artificial cerebrospinal fluid solution in which glucose and oxygen were omitted. Na+ and HVA Ca2+ currents were analyzed by whole-cell patch-clamp recordings from acutely isolated rat striatal neurons. Excitatory postsynaptic potential was measured following synaptic stimulation in corticostriatal slices by sharp intracellular microelectrodes. Results— Neuroprotection against in vitro ischemia was observed in slices treated with carbamazepine (CBZ), valpr...