FIGURE 1.

The structure of the myelin sheath. The myelinated axon (A), bilayer membranes (B). (A): The ratio of 2xRo to 2xRi (in A) is the g-ratio. Ri—inner radius; Ro—outer radius (B): Each bilayer of thickness DB is separated by cytoplasmic and extracellular water gaps of thicknesses DI and DO, and effective protein thickness DP is occupied by the fraction of MBP constituting the cytoplasmic water gap. Adapted from Min Y, et al. Proc Natl Acad Sci U S A. 106(9): 3154–3159.