Introduction

One of the most interesting and controversial aspects of epilepsy research is the relationship between interictal spikes and seizures. Do these phenomena result from the same epileptogenic processes? What does the presence of interictal spikes tell us about conditions in the neuronal network expressing them? How do these two phenomena respond to pharmacological treatments? Does the presence of interictal spiking alter the probability of the network undergoing seizure activity? These and many other long-standing questions remain unresolved.

Our purpose in writing this chapter is not to answer these questions, but to point to model systems in which the relationship between interictal activity and seizures can be explored. Here we describe brain slice preparations in which the slices are subjected to repetitive electrical stimulation. The stimulation transforms the networks so that they exhibit hyperexcitable behavior that is quite similar to the interictal and ictal discharges seen in vivo. We compare stimulation models to a model that utilizes low magnesium artificial cerebrospinal fluid (ACSF) to produce seizure-like activity and epileptiform bursts. We aim to illustrate not only the techniques for implementing such stimulation models, but to offer some sense of the potential rewards and pitfalls that accompany their use.