ULTIMATE COMPUTING - Quantum Consciousness Studies

106 Cytoskeleton/Cytocomputer
dynamically active in moving elements through the cytoplasm. The dynamic
MTL moves material in a saltatory manner at velocities equivalent to axoplasmic
transport. A co-pioneer with Porter in the observation of cytoplasmic ground
structure, Mark Ellisman (1981) of the University of California at San Diego has
observed that MT and filaments are analogous to rigid skeletal elements such as
bone, and that the microtrabecular lattice may be appropriately equated with work
producing components such as skeletal musculature. Thus Ellisman suggests a
more appropriate description of the MTL might be “cytomusculature.”
In neurons, wispy MTL strands radiate from MT and neurofilaments at right
angles into the cytoplasm, often interconnecting MT with other MT and
neurofilaments with neurofilaments. At the synapse, the MTL appears intimately
involved in both neurotransmitter release and post synaptic receptor mechanisms.
Presynaptic terminals demonstrate notable MTL crosslinking among synaptic
vesicles and among vesicles and synaptic membranes. In post synaptic dendrite
MTL, linkages are visible among filamentous subsynaptic densities and the other
elements of dendritic cytoplasm. Where axonal cytoplasm enters synaptic regions,
transitions occur in the form of the MTL. In axons, cross linkages are clearly
exhibited between MT, filaments, and other components. However, in presynaptic
terminals and dendrites, the MTL network is more similar in structure to isolated
actin-myosin gels observed in non neuronal cells. Raymond Lasek (1981) of
Case-Western Reserve University has shown that the cytoplasm of nerve axon
growth cones, which differs from axonal cytoplasm, is rapidly converted from the
axonal variety to the growth cone variety in axons severed from their cell bodies.
Thus “local” factors appear able to transform axoplasm to synaptic terminal
cytoplasm, or axoplasm to growth cone cytoplasm. The MTL is the fine structure
and texture of cytoplasm.
MTL activities appear to be dependent on calcium ion concentration.
Ellisman’s work shows that high calcium exposure causes the MTL to shorten
and deform, leaving free ends or “nubbins.” In normal axoplasm, different forms
of MTL corresponding to both high and low calcium ion concentration appear to
be found concurrently. These may correspond with “sol” and “gel” states
determined by other techniques. Ellisman suggests that calcium may be the
coupling agent for the dynamic aspects of the MTL in terms of location, extent
and form of crossbridging of cellular constituents. Calcium regulated by
cytoskeletal structures, or membranes, and the MTL itself may be locally dynamic
and patterned. Standing waves, dissipative patterns, or holograms “hardwired” in
MTL could be representations of calcium coupled states in cytoplasm.