Development of Epilepsy-on-a-chip System for High-throughput Antiepileptogenic Drug Discovery

Abstract Epilepsy is one of the most common neurological disorders and affects millions of people in the United States. Currently available antiepileptic drugs require continuous administration for suppression of seizures and have not been shown to prevent the development of epilepsy (epileptogenesis). The discovery of antiepileptogenic drug is complicated by the long time course of epileptogenesis in animal models of epilepsy and the requirement of continuous monitoring of epileptiform activity in vivo for the assessment of drug efficacy. In recent years, organotypic hippocampal cultures have been increasingly used as an in vitro model of post-traumatic epilepsy in both basic and translational research. Epileptogenesis in this in vitro model has a compressed time scale and can be monitored by detection of electrographic and biochemical markers of seizure-like activity. However, the lack of a scalable chronic electrical recording platform is a significant bottleneck in high-throughput antiepileptogenic drug discovery using organotypic cultures.In an effort to circumvent the throughput limitations of in vitro antiepileptogenic drug discovery, a hybrid microfluidic-multiple electrode array (µflow-MEA) technology was developed for scalable chronic electrical assay of epileptogenesis in vitro. Specifically, the microfluidic perfusion technique was utilized to miniature the culture platform, which enabled the long-term maintenance of an organotypic culture array on a single device. The integration of the microfluidic perfusion system with a customized planar MEA allowed for parallel continuous recordings. As a proof-of-concept demonstration, a pilot screen of receptor tyrosine kinase (RTK) inhibitor library was performed on µflow-MEA based electrical assay platform. The screen results revealed significant antiepileptogenic effect of cFMS RTK inhibitor.This thesis also provides further validation of the organotypic hippocampal culture model of epilepsy by investigating the influence of culture medium composition on epileptogenesis. We found that epileptogenesis occurred in any culture medium that was capable of supporting neural survival, indicating that culture medium composition has limited influence on epileptogenesis in organotypic hippocampal cultures.It is hoped that the techniques presented in this thesis will accelerate the antiepileptogenic drug discovery and contribute to the development of new therapeutics to treat individuals at risk of epileptogenesis.