Fig. 13.

A: bar graph shows the density of myelinated fibers around PCs at the same 3 regions (2, 6, and 9) as in Fig. 11. Counts were made for the midsagittal section (A) and 3 sections more lateral (D, G, and J) as shown in Fig. 12. At each lateral position, myelinated fiber density is highest in the region 6. B: low and high magnification electron micrographs show axons in the midsagittal section A. Cell body at the top right is part of a PC. High-magnification image shows a detail of the myelin sheath of a ∼1 μm axon ensheathed by ∼16 layers of myelin.