Fig. 3.1. Transverse section of the anterior commissure of a 16 year old monkey. In younger monkeys the myelin sheaths are compact and do not display significant distortion. Most of the profiles are sections through the internodal lengths of myelin, where there is a gap between the axolemma and the membrane on the inner face of the myelin sheath. At paranodes (paranodes: arrows) these two membranes come close together to form a seven layered complex, and at paranodes the thickness of the myelin sheath depends upon how close to the node of Ranvier the section is taken.
