RanvierSchnitten

RanvierSchnitten are histological preparations that focus on the nodes of Ranvier within myelinated axons. The term combines Ranvier, the physiologist who described gaps in the myelin sheath, with Schnitt, the German word for section. In these preparations, nerve tissue is fixed, embedded, and cut into thin sections so that the organization around individual nodes can be studied. Staining or labeling methods highlight the node and its surrounding regions, including the paranodal and juxtaparanodal zones.

Nodes of Ranvier are short gaps in the myelin sheath where voltage-gated sodium channels concentrate, enabling saltatory conduction along the axon. The paranodal region forms axo-glial junctions that flank the node, while the juxtaparanodal region contains other ion channels and membrane proteins. RanvierSchnitten thus reveal the precise ultrastructure and the relationship between the node, the paranode, and the adjacent myelinated segments.

Techniques used for RanvierSchnitten include light microscopy with immunohistochemical labeling for nodal and paranodal markers (such as Na+ channels, Caspr, and neurofascin), as well as electron microscopy for ultrastructural detail. Serial sections can support three-dimensional reconstructions of node architecture.

Applications of RanvierSchnitten encompass basic neuroscience research on nerve conduction, myelination, and axon–glia interactions, as well as investigations into demyelinating diseases and remyelination processes. Limitations include tissue orientation, fixation quality, and resolution constraints inherent to sectional techniques. See also: nodes of Ranvier, saltatory conduction, myelin, paranodes.