Animal models of focal epilepsy

Animal models are important in the study of the development and expression of focal seizures as well as in the preclinical evaluation of antiepileptic treatment. Many different models are available, including acute and chronic models for simple partial seizures and models for complex partial seizures. Work on models has revealed that the pathophysiology of seizure disorders includes several neurotransmitter and membrane channel alterations. In addition, epileptogenesis of focal epilepsy has been shown to involve the selective loss of neurons and axonal reorganization. Antiepileptic treatment still hinges on three general themes: modulation of voltage-dependent ion channels involved in spike propagation and burst generation, enhancement of GABA-mediated inhibition, and suppression of excitatory amino acidergic activity. Many antiepileptic drugs have proven efficacy against focal seizures in animal models as well as patients. More recently developed antiepileptic drugs may prove to be superior in the alleviation of intractable partial seizures. The three general themes of antiepileptic drug action still dominate the development of antiepileptic treatment strategies. Too much emphasis on the classical models of focal epilepsy may hamper the development of innovative strategies. On the other hand, continued research on new and existing models may broaden our knowledge of the pathophysiological processes underlying focal epilepsy, and inspire new avenues in antiepileptic treatment development.