||Scott T. Brady, George J. Siegel, R. Wayne Albers and Donald L. Price, editors, Basic Neurochemistry (Eighth Edition) Principles of Molecular, Cellular, and Medical Neurobiology, 2012 Elsevier, chapter 8 - Axonal Transport, Pages 146-164, Gerardo A. Morfini, Matthew R. Burns, David L. Stenoien, Scott T. Brady, p.155 right column 3rd paragraph
||P..155 right column 3rd paragraph: "Slow Component b (SCb) represents a complex and heterogeneous rate component, including hundreds of distinct polypeptides ranging from cytoskeletal proteins like actin (and tubulin in some nerves, see Oblinger et al., 1987) to soluble enzymes of intermediary metabolism (such as glycolytic enzymes). The structural correlate of SCb is not as easily identifiable as the MTs (microtubules) and NFs (Neurofilaments) of SCa (Slow Component a). Actin is presumed to form MFs (microfilaments), but actin represents only 5–10% of the protein in SCb and a significant fraction of axonally transported actin is deposited in the membrane cytoskeleton of the axon. Most proteins in SCb may be assembled into labile aggregates that can interact transiently with the cytoskeleton. Recent studies with live cell imaging of fluorescent SCb proteins in transport are consistent with this idea (Roy et al., 2007)."