Electron microscopic examination of the myelinated axons of corpus callosum in perfused young and old rats

In this study, the myelinated axons of parts of the corpus callosums of young and old rats were examined under the electron microscope and a grading system was performed for quantiating the ultrastructural pathological changes of these axons. Except the old splenium group, the only ultrastructural pathological change, observed in the myelinated axons was the separation in myelin configuration. In addition to this finding, in the old splenium group, in some of the myelinated axons, an interruption was observed in the myelin configuration. Additionally, these ultrastructural pathological findings were present in the larger sized myelinated axons of the corpus callosum.