ULTIMATE COMPUTING - Quantum Consciousness Studies

160 Models of Cytoskeletal Computing
ionic/electrical currents. They suggested that MT behaved as “mechanochemical
engines driven backward.” Compression or bending of MT would cause release of
bound ions from MT subunits, resulting in an ion flux. Moran and Varela saw
these ionic currents capable of generating membrane depolarization, being
perhaps the first to suggest that MT can regulate membranes. Each tubulin dimer
reversibly binds 16 calcium ions so ionic fluxes of significant current could result
from an active assembly of parallel MT. This process may be analogous to the
coordinated release of calcium ion waves by sarcoplasmic reticulum in muscle
cells which triggers actin-myosin contractile interactions. Calcium waves are also
thought to regulate the bending and waving of cilia and flagella, and can regulate
the cytoskeletal “ground substance” by coupling to sol-gel states. Moran and
Varela’s contribution was to observe that MT could release ions such as calcium
in a controlled and modifiable manner useful for intracellular communication.
8.2.3 Cytomolecular Computing/Conrad and Liberman
Wayne State University computer scientist Michael Conrad and Soviet
information scientist E. A. Liberman have collaborated to consider aspects of
biomolecular computing including the cytoskeleton. They consider that the
“computing power of the brain is primarily based on intracellular processes.”
They propose that the cyclic nucleotide system (energy rich molecules such as
cyclic AMP) sculpts three dimensional dynamic patterns in the cytoplasm of
neurons and other cells which are the analog texture of real time information
processing. Conrad and Liberman view reaction diffusion patterns of cyclic AMP,
regulated and perceived by both cell membranes and the cytoskeleton, as a link
between macroscopic neural activities and molecular scale computing. Conrad,
known for his conceptualization of protein enzymes as possible computer
components (Chapter 1), has also advanced the notion of molecular automata
within cells (Conrad, 1973). He and Liberman suggest that the intracellular
cytoskeleton perceives mechanical stretch or distortion subsequent to membrane
events and accordingly regulates cyclic AMP and other biomessengers.
Conrad and Liberman (1982) suggest:
in neurons, mechanical stimulation appears on movement of the
intraneuron tubule skeleton and micromuscle ... details of the
skeleton and micromuscles (are) suitable for constructing the
molecular analog ... of the real physical field in which this system
moves.
Conrad and Liberman view a molecular analog within the cytoskeleton as a
representation of the external world. Extrapolated to complex systems like the
brain, such a cytoskeletal analog could suffice as a medium of cognition.
Conrad (1985) notes that
highly parallel signal processing and vibratory behavior on the part
of microtubules and other cytoskeletal elements could play a
significant role.
8.2.4 MT Signal Processing/DeBrabander
Cell biologist Marc DeBrabander has extensively studied activities of the
cytoskeleton in mitosis and cellular organization in general. He and his colleagues
at Belgium’s Janssen Pharmaceutica Research Laboratories (DeBrat bander,
DeMey, VandeVeire, Aerts and Geuens, 1975, 1986) have examined the
distribution and movement of cell membrane proteins and gathered evidence that
they are linked to the cortical actin filament system. In turn, the ordered activity