Characterization of electrophysiological interaction in hippocampal circuitry during learning

Abstract

Since the historical report of the H.M. case, much has been investigated on the hippocampal roles, specially on its involvement in memory function and epilepsy. Many contradictions concerning hippocampal functions still persist, despite large number and variety of published research on this theme. Specifically, hippocampus involvement in memory seems to depend on the type, emotional and motivational aspects. These divergences may be due to the fact that the function of a given neuronal structure depends upon its effective connectivity. The hippocampus is interconnected with distinct structures (amygdala, córtex, septum etc) that mediates distinct neural processes, be it physiologic or pathologic ones. Furthermore, hippocampus is divided in different subregions (DG, CA1, CA2, CA3) with neuroanatomic, neurochemical and physiologic specificities. Recent studies have shown that these subregions have distinct functions in different learning stages, as acquisition, consolidation and retrieval, suggestin distinct patterns of effective conectivity in these processes. Furthermore, the comprehension of electrophysiologic interactions between different neural structures have contributed to pathology understanding. So, the study of the electrophysiologic interactions of the distinct hippocampal areas in real time may propiciate a better understanding of the hippocampus role in physiologic (e.g. memory) and pathologic (e.g. epilepsy) processes. Therefore, the objective of the present work is to assess the dinamics of information flow in the hippocampal circuitry during learning in different behavioral tasks (in colaboration with Prof. Dr. Maria Gabriela Menezes de Oliveira, Depto. Psicobiologia, UNIFESP) that involve distinct emotional and motivational components using real time, synchronised, behavioral, action potentials and field potentials recording. We expect to to infere the patterns of effective conectivity in the hippocampal areas in the different learning stages.