Mechanisms underlying epileptiform burst discharge

TLDR

Epileptic neurons possess intrinsic burst‑generating properties, and extrinsic factors that disturb the depolarizing‑hyperpolarizing balance can trigger these bursts. The study hypothesizes that calcium ion influx is the key driver of burst discharge. Calcium‑mediated excitation is modulated by synaptic inputs, hyperpolarizing conductances, cell morphology, membrane properties, and the extracellular environment. The hypothesis integrates data from penicillin and alumina models and offers experimentally testable concepts for future study.

Abstract

Abstract Studies of hyperexcitable cells in alumina‐gel and penicillin epileptogenic foci suggest that epileptic neurons have intrinsic burst‐generating properties. The burst mechanism may be released or triggered by a number of extrinsic factors which disrupt the normal depolarizing‐hyperpolarizing balance. This paper presents the hypothesis that the most important influence for burst discharge is influx of calcium ions. This excitatory effect is modulated by synaptic inputs, hyperpolarazing conductances, cell morphology and membrane characteristics, and the extracellular milieu. The hypothesis incorporates findings from both penicillin and alumina models of epilepsy and provides experimentally testable concepts for further investigation.