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NJIT Mathematical Biology Seminar

Tuesday, February 12, 2008, 4:00pm
Cullimore Hall 611
New Jersey Institute of Technology

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Developmental patterns and modulations of Neuronal circuits

Einat Fuchs

Department of Zoology, Tel Aviv University

Despite large variability in complexity and size of different invertebrate and vertebrate nervous systems, many of them are spatially organized in multiple compact, tightly connected modules or sub networks (ganglia, strata and maps). Although structurally and functionally distributed, the integration and coordination of such modules is in the basis of all motor performances and cognitive functions, allowing rapid information transfer and generation of coherent cognitive states. We are studying developmental patterns of neuronal systems, focusing on the development of interconnected spatial and functional cell assemblies, their firing patterns, synchronization and information capabilities. We monitored the electrical activity and structural organization of cultured networks during their evolvement from a mixture of dissociated cells into active networks and found distinct phases in the course of network development. The rapid initial neurites growth of individual cells seeking to connect to neighbouring neurons had changed once interconnections between cells had formed and neurons started to migrate and aggregate into packed clusters interconnected by a few thick bundles. In parallel the neuronal firing pattern was changed from sporadic firing of individual neurons as independent units into complex collective network dynamics that was marked by bursting events with inter-neuronal synchronization and non-arbitrary temporal ordering. Quantification of these experimental observation as well as theoretical analysis of artificial neuronal networks during development reveals basic conditions allowing neuronal systems to maintain a freedom for local specificity in the presence of long-range integration of inputs from various origins.