It has been known for more than a century that the human temporal lobe, and in particular the neuronal networks of the hippocampus, are prone to epileptic seizure. There has been substantial debate as to whether this is due to the relative simple network design that might have inadequate inhibitory safeguards, or intrinsic electrophysiological characteristics of individual neurons within these circuits. The fact that normal activity for many of these neurons includes repetitive firing – described as “burst firing” – does suggest that membrane currents can fluctuate at or near to a critical threshold. Given what might be thought of as a hair trigger, one could argue that relatively small modification of ionic balance might readily result in synchronization of firing within a population of these cells, this being the pathological condition observed during epilepsy.

The present modeling work examines the ionic currents that mediate normal burst firing of hippocampal neurons. This should be of intrinsic interest to those who are working on basic physiology. It has clinical implications as well, possibly providing a platform for testing how single-unit and network physiology can degenerate into epileptic synchrony.