Investigators' Workshop Monday Afternoon Session 3:15 p.m.‐4:45 p.m.

Terence J. O’Brien¶, Gilles van Luijtelaar*, Didier Pinault†, Graeme Jackson‡ and John R. Huguenard§
*NICI‐Biological Psychology, Radboud University Nijmegen, Nijmegen, Netherlands; †INSERM U666, physiopathologie clinique et expérimentale de la schizophrénie, Université Louis Pasteur (Faculté de Médecine), Strasbourg, France; ‡The Brain Research Institute, The University of Melbourne, Melbourne, VIC, Australia; §Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA and ¶Dept of Medicine, University of Melbourne, Parkville, VIC, AustraliaSummary: The International League Against Epilepsy (ILAE) dichotomizes types of seizures into focal and generalized types on the basis of whether they are appear to start in a geographically localized region of one hemisphere or bihemispherically in a diffusely distributed manner. One of the most classical and common examples of a “generalized” seizure type is absence seizures, which are characterized by abruptly commencing bihemispheric synchronous spike and wave discharges on the EEG. However evidence is accumulating that absence seizures may actually commence in a geographically localized “focus” within the somatosensory cortex. Most of this data comes from electrophysiological studies in genetic models, but there is some emerging data from electrophysiological and functional imaging studies in human with absence epilepsies. The proposed workshop will present and discuss data relating to the localization, neurophysiology and underlying pathological basis of the generator of absence seizures in the cortex of rodents, as well as debate the evidence that this may be translatable to human suffers of these absence epilepsies. Gilles van Luijtelaar will discuss “Neurophysiological and morphological evidence for the cortical absence seizure focus in the WAG/Rij rat”. Didier Pinault will discuss “Layer VI pyramidal neurons in the somatosensory cortex generate spike‐and‐wave discharges in GAERS”. Graeme Jackson will discuss “The evidence for a cortical absence seizure focus in humans: electrophysiological and imaging studies”. John Huguenard will be the discussant.