Electrodynamic Signaling by the Dendritic Cytoskeleton (Google Workshop on Quantum Biology)
27Google Workshop on Quantum Biology
Electrodynamic Signaling by the Dendritic Cytoskeleton
Presented by Jack Tuszynski
October 22, 2010
ABSTRACT
A model describing information processing pathways in dendrites is proposed based on electrodynamic signaling mediated by the cytoskeleton. Our working hypothesis is that the dendritic cytoskeleton, including both microtubules (MTs) and actin filaments plays an active role in computations affecting neuronal function. These cytoskeletal elements are affected by, and in turn regulate, a key element of neuronal information processing, namely, dendritic ion channel activity. We present a molecular dynamics description of the C-termini protruding from the surface of a MT that reveals the existence of several conformational states, which lead to collective dynamical properties of the neuronal cytoskeleton. Furthermore, these collective states of the C-termini on MTs have a significant effect on ionic condensation and ion cloud propagation with physical similarities to those recently found in actin-filaments and microtubules. We also discuss experimental findings concerning both intrinsic and ionic conductivities of microfilaments and microtubules which strongly support our hypothesis regarding internal processing capabilities in neurons. Our ultimate objective is to provide an integrated view of these phenomena in a bottom-up scheme, demonstrating that ionic wave interactions and propagation along cytoskeletal structures impacts channel functions, and thus neuronal computational capabilities. The issue of quantum versus classical character of these interactions will be discussed.
About the speaker: Professor Jack Tuszynski received his M.Sc. with distinction in Physics from the University of Poznan (Poland) in 1980. He received his Ph.D. in Condensed Matter Physics from the University of Calgary in 1983. He did a Post-Doctoral Fellowship at the University of Calgary Chemistry Department in 1983. He was an Assistant Professor at the Department of Physics of the Memorial University of Newfoundland from 1983 to 1988, and at the University of Alberta Physics Department from 1988 to 1990, an Associate Professor from 1990 to 1993 and a Full Professor since 1993. He joined the Division of Experimental Oncology within the Cross Cancer Institute as the Allard Chair in 2005. He is on the editorial board of the Journal of Biological Physics, Journal of Biophysics and Structural Biology (JBSB), Quantum Biosystems, Research Letters in Physics, Water: a Multidisciplinary Research Journal and Interdisciplinary Sciences-Computational Life Sciences. He is an Associate Editor of The Frontiers Collection, Springer-Verlag, Heidelberg.