Serial analysis of gene expression in the hippocampus of patients with mesial temporal lobe epilepsy.

Hippocampal sclerosis constitutes the most frequent neuropathological finding in patients with medically intractable mesial temporal lobe epilepsy. Serial analysis of gene expression was used to get a global view of the gene profile in human hippocampus in control condition and in epileptic condition associated with hippocampal sclerosis. Libraries were generated from control hippocampus, obtained by rapid autopsy, and from hippocampal surgical specimens of patients with mesial temporal lobe epilepsy and the classical pattern of hippocampal sclerosis. More than 50,000 tags were analyzed (28,282, control hippocampus; 25,953, hippocampal sclerosis) resulting in 9206 (control hippocampus) and 9599 (hippocampal sclerosis) unique tags (genes), each representing a specific mRNA transcript. Comparison of the two libraries resulted in the identification of 143 transcripts that were differentially expressed. These genes belong to a variety of functional classes, including basic metabolism, transcription regulation, protein synthesis and degradation, signal transduction, structural proteins, regeneration and synaptic plasticity and genes of unknown identity of function. The database generated by this study provides an extensive inventory of genes expressed in human control hippocampus, identifies new high-abundant genes associated with altered hippocampal morphology in patients with mesial temporal lobe epilepsy and serves as a reference for future studies aimed at detecting hippocampal transcriptional responses under various pathological conditions.