Figure 4.
Comparison between rat spinal cord (CNS) and sciatic nerve (PNS) myelin packing disorder and the crystallinity of myelin. The square of the full-width at half-maximum for each reflection (w 2) is plotted against the fourth power of the Bragg order (h 4). Dashed lines behind the data represent linear least-squares fits for spinal cord (blue) and sciatic nerve (red). The slope of each line is directly related to the amount of membrane-packing disorder in the tissue, while the intercept is inversely proportional to the crystallinity (the coherence length or the average number of layers of myelin; Inouye et al., 1989 ▶). The coherence lengths for spinal cord and sciatic nerve were approximately eight and 12 repeats (membrane pairs), respectively.