Large-scale analysis of gene expression in epilepsy research: is synthesis already possible?

DNA microarrays are now popular tools for large-scale studies of gene expression in the brain in both physiologic and pathologic conditions. Here, we review the few available papers describing the use of microarrays in experiments relevant to temporal lobe epilepsy. Review of the data indicates that products of genes regulated during epileptic processes belong to a variety of functional classes, including signal transduction, transcription regulation, protein synthesis and degradation, basic metabolism, and structural proteins. There is surprisingly little overlap in gene lists from different studies. This might be related to the limited sensitivity of microarrays or to differences in the experimental setup, such as the use of different animal models, time points, and microarrays. Despite obvious problems with interpretation of the vast amount of information derived from microarray experiments, these data are potentially excellent tools for creating new hypotheses about events occurring during circuitry reorganization in the brain that results in lowered seizure threshold and epilepsy.