Models and mechanisms of experimental epilepsies

Purpose: To review the value of experimental models of epilepsy to help us understand the underlying basic neuronal mechanisms. Methods: The methods addressed here include a variety of acute and chronic experimental epilepsies and their investigation in vitro, in vivo, and in computer simulations. Results: Epileptic discharges are emergent properties of neuronal networks, depending crucially on intrinsic neuronal properties, and on the structural and functional organisation of the synaptic networks that interconnect them. Fast oscillations are another emergent property of these networks; while they are involved in normal function, they can play a crucial role in the initiation of at least some kinds of focal seizure. Discussion: Brief "interictal" epileptic events are now relatively well understood. Rather less so are the mechanisms of chronic epileptic foci, and particularly of the prolonged hyper-synchronous hyperexcitability characteristic of focal seizures, but here too progress is being made, offering the prospect of better targeted treatments.