Topiramate-antagonism of L-glutamate-induced paroxysms in planarians

We recently reported that NMDA (N methyl D-aspartate) and AMPA (alpha-amino-3 hydroxy-5-methylisoxazole-4-propionic acid) induce concentration-dependent paroxysms in plananans (Dugesia dorotocephala) Since the postulated mechanisms of action of the sulfamate substituted monosaccharide antiepileptic drug topiramate include inhibition of glutamate-activated ion channels we tested the hypothesis that topiramate would inhibit glutamate induced paroxysms in our model We demonstrate that (1) L-glutamate (1-10 mM) but not D-glutamate induced dose-related paroxysms and that (2) topiramate dose-relatedly (03-3 mM) inhibited L-glutamate induced paroxysms These results provide further evidence of a topiramate sensitive glutamate receptor mediated activity in this model (C) 2010 Elsevier B V All tights reserved