ICTOGENESI ED EPILETTOGENESI IN UN MODELLO DI EPILESSIA DEL LOBO TEMPORALE

ABSTRACT Temporal lobe epilepsy (TLE) is the most common partial epilepsy and it is often associated with pharmacoresistance. Surgery has become the standard of care for patients with intractable temporal lobe epilepsy, Pre-surgical analyses with intracranial electrode to identify the epileptic focus reveal the presence of a characteristic high frequency low voltage activity at seizure onset. Previous work in our laboratory demonstrated that this pattern is reproducible in the model of guinea pig isolated brain perfused with bicucullin and pilocarpine (Uva et al., 2005; 2008). Intracellular recording during seizure onset reveal an intense activation of GABAergic neuron while principal cell are silent in medial entorinal cortex (Gnatkovsky et al., 2008). To confirm that ictogenesis pattern is a network property independent from the substance used to induce seizure we perfused a potassium channel blocker, 4AP, in the guinea pig brain. Furthermore, in vivo study injecting Kainic acid in the right hippocampus in anesthetized and freely moving guinea pig in acute and chronic period was performed. Both in vitro and in vivo study confirmed the presence of high frequency and low voltage signal.