Figure 9.

Normal ultrastructure of paranodal myelin in short-term netrin-1- and DCC-deficient cerebellar slice cultures. The organization of paranodal myelin was studied by transmission electron microscopy in short-term organotypic slice cultures derived from newborn netrin-1^−/− or DCC^−/− animals and their wild-type littermates (A, B; F, G, respectively). At this age, paranodal myelin was well organized in both wild-type and mutant cultures. In almost every paranode studied at this age, transverse bands linked the axonal and oligodendrocyte membranes, and paranodal loops were closely apposed to each other. Detached and everted loops were rarely observed in short-term cultures (C–E, H–J). Magnification: 25,000×. Scale bars, 500 nm. Error bars indicate SEM.