The Cytoskeletal Connection

Microtubules, centrioles, and the cytoskeleton evolved to take command of biology. By being at the right size scale and moving in the right time scale, they appear capable of utilizing many forms of available energy. MT polarity, periodic structure, and helical lattice array of conformationally programmable subunits qualify them as "ultimate computers" and nanoengines as well, generating purposeful force and movement. They may capture and self focus electromagnetic radiation, induce coherency, and propagate energy quanta with minimal loss. Propagation may manifest as coherent polarization waves as described by Fröhlich, massless bosons as described by Del Giudice or as solitons as described by Davydov. Charge density waves or proton transfer at MT surface layers of ordered water, and positively charged counter ions such as calcium are other possible modes available for cytoskeletal based information and energy transfer.

Figure 8.14: "Kink-like" pattern continues left to right through MT automaton. Such dynamic patterns can represent and compute information, serve as binding sites for transported molecules, designate MAP and inter MT bridge attachment sites, or generate coherent waves of calcium coupled sol-gel states.

Figure 8.14: "Kink-like" pattern continues left to right through MT automaton. Such dynamic patterns can represent and compute information, serve as binding sites for transported molecules, designate MAP and inter MT bridge attachment sites, or generate coherent waves of calcium coupled sol-gel states.

MT electron surpluses occur due to an abundance of acidic amino acids. With the intrinsic polarity of each tubulin dimer subunit, MT reside in a strong polar field or "electret" which possesses piezoelectric properties. Each MT subunit can thus "integrate," being capable of absorbing and sensing input in the form of acoustical energy, optical photons, chemical ATP, altered potential changes, fluxes of calcium and other ions, and responding with conformational changes accordingly. Each subunit within a microtubule lattice can not only represent information, but can input and output information into an ongoing automaton. Coherent oscillations in MT tubulin subunit states among regional forests of microtubules can provide a communicative medium in which any subunits which are out of phase induce waves of phase uncoupling along MT structure. Alterations which disturb coherency could be amplified by collective oscillations among cytoskeletal macroassemblies like rotatory centrioles or tensegrity structures of MT wound by contractile actin filaments.

Several other possible modes of information management present themselves in the structure of MT. Could the gaps between tubulin subunits act like pores? The relative abundance of electronegative charges in the outer surface of cylindrical microtubules may create gradients across tubule walls if the MT interior is neutral or positive. Presently unmeasurable, even a small gradient across 4 nanometer MT walls would comprise a significant voltage field. Thus a propagating soliton, charge density wave, or transient osmotic swelling of nerve processes could open "cracks" among the tubulin subunits to allow for ion flux or radiation of electromagnetic energy focused and trapped within MT. Alternatively, an electronegative MT interior core might support Del Giudice's suggestion of cytoskeletal superconductivity. Self-focused energy exerting force perpendicular to the long axis of MT could account for mysterious effects such as the perpendicular birth of daughter centrioles and inter-MT MAP bridges. Energy or ion fluxes radiated from MT due to propagating waves would be coherent due to spatial periodicity of the gaps between the tubulin subunits, and could thus form the basis of coherent wave interference in a three dimensional hologram. Coupled to calcium/sol-gel states, holographic cytoplasm may be an "infoplasmic" canvas for dynamic biological information.

In the brain, highly parallel arrangements of cytoskeletal proteins within asymmetrical axons and dendrites suggest analogies to parallel computing. Propagation of action potentials or dendritic depolarization waves could induce sequences of alterations of MT subunit states due to influx of calcium, alteration of electrical fields, or direct mechanical effects as sodium and water transiently swell the nerve process. Signals may cooperatively reverberate throughout the cytoskeleton by waves of calcium release and uptake, mechanical/electrosolitons propagating through the cytoskeletal lattice, and/or lateral propagation through sidearms and other components of the cytoskeletal network. Transient fluxes of calcium resulting from conformational waves propagating down cytoskeletal lattices in parallel with action potentials or dendritic current waves can result in traveling frames of dynamic imagery. Sequences of image frames traveling through holographic cytoplasm and changing with each nerve firing may collectively be the "Mind's Eye, the "grain of the engram."

The current prevalent model of brain function is the "neural network," a collective dynamical system whose output is determined by the states of component neuronal synapses. In turn, the state of each synapse is determined by other neurons modulated by collective dynamic effects of the interneuronal cytoskeleton. In turn, the cytoskeleton is a collective dynamical system whose net activity is determined by the states of its component subunits. Their states, in turn, are determined by another level of organization including cytoplasmic factors, ordered water and ions, genetic isozymes of individual subunits, and lower level cytoskeletal elements such as the microtrabecular lattice. Each cytoskeletal subunit is a computer capable of integrating multiple inputs to a specific output state. Cognitive processes which have been ascribed to a neural net concept may thus be more accurately interpreted as a fractal hierarchy of dynamical systems which are highly parallel, highly interconnected, and of increasing capacity as they become more microscopic. Collective effects may occur at each level and at successively more macroscopic levels. The net effect may be consciousness.

Microtubules and the cytoskeleton created their place in evolutionary history by being problem solvers, organelle movers, cellular organizers, and intelligence circuits. Where do they go from here?

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