The core will provide important resources necessary for each project's data-gathering, statistical analysis and interproject coordination. Dr. Dennis Spencer will be responsible for selecting patients appropriate for this study, providing the tissue, arranging weekly conferences to maintain interproject integrity; he will help develop hypotheses that connect clinical epilepsy issues with the basic research; he will coordinate the imaging data such that precise neuroanatomical relationships can be maintained, and is responsible for the overall program coordination. Computerized quantitative imaging is critical for patient selection criteria, and intraoperative imaging is necessary to provide important cytoarchitectonic correlation for each project. The presumptive pathological substrate must be compared to normal MRIs particularly since this is a quantitative examination. New funds are requested in this resubmission for a normative MRI volumetric study to provide this critical comparison. Dr. Gregory McCarthy will supervise the imaging research assistant in this regard. Dr. Jung Kim proves a central resource by providing qualitative neuropathological assessment and is responsible for the quantitative hippocampal neuronal, and glial cell counts which underlie all further morphometric, physiological and biochemical assessment. A patient data base has already been established, but statistical management for this program will be provided by Yale's Department of Biostatistics.