Exploration of hierarchical leadership and connectivity in neural networks in vitro.

Exploration of hierarchical leadership and connectivity in neural networks in vitro.

Date: December 2008
Creator: Ham, Michael I.
Description: Living neural networks are capable of processing information much faster than a modern computer, despite running at significantly lower clock speeds. Therefore, understanding the mechanisms neural networks utilize is an issue of substantial importance. Neuronal interaction dynamics were studied using histiotypic networks growing on microelectrode arrays in vitro. Hierarchical relationships were explored using bursting (when many neurons fire in a short time frame) dynamics, pairwise neuronal activation, and information theoretic measures. Together, these methods reveal that global network activity results from ignition by a small group of burst leader neurons, which form a primary circuit that is responsible for initiating most network-wide burst events. Phase delays between leaders and followers reveal information about the nature of the connection between the two. Physical distance from a burst leader appears to be an important factor in follower response dynamics. Information theory reveals that mutual information between neuronal pairs is also a function of physical distance. Activation relationships in developing networks were studied and plating density was found to play an important role in network connectivity development. These measures provide unique views of network connectivity and hierarchical relationship in vitro which should be included in biologically meaningful models of neural networks.
Contributing Partner: UNT Libraries
Identification of functional information subgraphs in cultured neural networks

Identification of functional information subgraphs in cultured neural networks

Date: July 13, 2009
Creator: Gintautas, Vadas; Bettencourt, Luis & Ham, Michael I.
Description: This paper accompanies an oral presentation on the identification of functional information subgraphs in cultured neural networks.
Contributing Partner: UNT College of Arts and Sciences
Spontaneous coordinated activity in cultured networks: analysis of multiple ignition sites, primary circuits, and burst phase delay distributions

Spontaneous coordinated activity in cultured networks: analysis of multiple ignition sites, primary circuits, and burst phase delay distributions

Date: June 2008
Creator: Ham, Michael I.; Bettencourt, Luis; McDaniel, Floyd Del. (Floyd Delbert), 1942- & Gross, Guenter W.
Description: This article discusses an analysis of multiple ignition sites, primary circuits, and burst phase delay distributions.
Contributing Partner: UNT College of Arts and Sciences