ULTIMATE COMPUTING - Quantum Consciousness Studies

104 Cytoskeleton/Cytocomputer
Lazarides (1980) has shown that different types of IF associate with specific
types of cells. For example, subunit structure defines five major classes of IF: 1)
keratin (“tonofilaments”), which are found in epithelial cells, 2) desmin filaments
predominantly found in smooth, skeletal and cardiac muscle cells, 3) vimentin
filaments, found in mesenchymal cells, 4) neurofilaments, found in neurons
(Figure 5.18), and 5) glial filaments, found in glial cells. Often two or more of
these classes co-exist in the same cell.
Neurofilaments appear to function as a three dimensional structural lattice
providing tensile strength to axons. Extruded axoplasm is a highly structured gel
rich in neurofilaments; exposure of the gel to calcium ion results in degradation of
neurofilaments and conversion of the gel to a more watery sol state, a
phenomenon generally attributed to dissolution of actin filaments.
All IF including neurofilaments appear to be phosphorylated although the
function that this could serve is not understood. IF are a distinct class separate
from MT and actin filaments, and Lazarides argues their biochemical and
morphological properties indicate they are involved in mechanically integrating
the various components of the cytoplasmic space. IF remain poorly understood;
their dense presence in neurons is mysterious, perhaps they participate in some
way in the cognitive functions of the nervous system. In Chapter 8, Barnett’s
theory of neurofilaments as “string transform” memory banks coupled to MT will
be described.
Figure 5.18: Cross section of small nerve axon. A. Microtubules with radial
MAPs. B. Neurofilaments, outnumbering microtubules about 10:1. C. Vesicle
being transported by microtubule axoplasmic transport. D. Crosslinked