[Neuropharmacology of a new model of partial epilepsy: GABA withdrawal syndrome]

In this work, we will describe the anatomical, behavioral, electrophysiological and neuropharmacological characteristics of a new model of focal epileptogenesis, the GABA-withdrawal syndrome (GWS). This particular model is original both because the manner in which is induced its electroclinical features, and because the physiopathological implications it represents. We will briefly describe the anticonvulsant effects of chronic, intracortical GABA infusions both in photosensitive baboons and in amygdala kindled rats, and show how the interruption of these infusions lead to the appearance of paroxysmal activity localized at the infusion sites. We will then describe more in detail this GWS, and show its dependency on GABA A receptor function. Furthermore, this GWS can be induced in hippocampal slices. Finally, we will propose the GWS as a useful model to study plastic phenomena in the brain and as a model of intractable epilepsy where screening of potential anticonvulsant agents will be feasible.