ULTIMATE COMPUTING - Quantum Consciousness Studies

88 Cytoskeleton/Cytocomputer
structure to centrioles. Insect mechanoreceptors and sensory cilia in our ears
appear to utilize MT to transduce mechanical force to the base of each cilium and
into the nervous system. Atema (1973) has proposed that propagation of
conformational changes along sensory cilia convey information to the cell as a
whole. Moran and Varela (1971) have suggested that sensory cilia MT act as
engines driven backwards. When an external force moves the microtubules of the
mechanoreceptor cilium, they suggest that the MT release ions like calcium which
can regulate cellular activities. Sensory transduction, guidance and alignment are
“intelligent” MT activities which are vital to biological growth, embryological
development, secretion, synapse formation and many other important biological
functions. Temporal and spatial control of MT deployment are achieved by two
mechanisms of pattern formation: directed assembly from MT organizing centers
(MTOC) and self assembly of multitubular arrays by means of intertubule linkers
(Figure 5.6). MT are the scaffolding, conveyor belts, and computers of living
cells.
Figure 5.6: Microtubule arrays interconnected by MAP bridges. Hollow circles are
MT arrays in cross section. By Paul Jablonka.
5.2.2 Microtubule Assembly and the Generation of Form
As changeable cellular superstructures, MT can assemble into rigid tubular
rods when and where they are needed, and then disassemble into subunits which
may be transported away by other MT. Like many viruses, MT self assemble
from their subunits into orderly polymers. The large increase in order, or negative
entropy associated with MT assembly would appear to flow upstream against the
second law of thermodynamics which, in general, states that order tends towards
disorder. The increase in order observed during MT assembly can be related to
the dispersal (disordering) of tightly bound structured water from the subunits as
they polymerize, consistent with the concept that MT subunits associate by
hydrophobic interactions (Chapter 6).