Inhibition of neuronal hypersynchrony in vitro differentiates levetiracetam from classical antiepileptic drugs

摘要: Field potentials were recorded from rat hippocampal slices in order to compare the electrophysiological action of new antiepileptic drug (AED), levetiracetam (LEV), with that classical AEDs, valproate, clonazepam and carbamazepine, on epileptiform responses induced by a 'high K(+)-low Ca(2+)' perfusion fluid. Increasing [K(+)] 3 7.5 mM decreasing [Ca(2+)] 2.4 0.5 mM, bathing fluid, produced population spikes (PSs) increasing amplitudes CA3 area slices, repetitive PSs evoked single stimuli, spontaneous bursts. Clinically relevant concentrations LEV, 32 100 micro M, consistently reduced second (PS(2)) third (PS(3)) spikes, number (N) per response. Levetiracetam M also opposed increase amplitude first PS (Delta PS(1)). Neither valproate 1 nor carbamazepine 50 any decrease Delta PS(1)and PS(2), but all decreased N. These results show LEV contrasts reference AEDs its ability antagonize neuronal (hyper)synchronization, highly seizure-prone slices.