Editing Node of Ranvier (section)

===Nodal formation===
The first event appears to be the accumulation of cell adhesion molecules such as NF186 or NrCAM.  The intra-cellular regions of these cell-adhesion molecules interact with ankyrin G, which serves as an anchor for sodium channels. In the PNS, this interaction has been elucidated. The Ig superfamily membrane protein NrCAM acts as a pioneer molecule in the formation of the nodes by recruiting ankyrin-G, a mediator protein in the connection of actin-spectrin cytoskeleton to the ion gated channels present at the node.<ref>{{cite journal |last1=Hill, Nishino, Nakajo |first1=AS, A, K |title=Ion channel clustering at the axon initial segment and node of Ranvier evolved sequentially in early chordates |journal=PLOS Genet |date=2008 |volume=4 |issue=12 |pages=e1000317 |doi=10.1371/journal.pgen.1000317 |doi-access=free |pmid=19112491 |pmc=2597720 }}</ref><ref>{{cite journal |last1=Lambert, Davis, Bennett |first1=S, JQ, V |title=Morphogenesis of the Node of Ranvier: Co-Clusters of Ankyrin and Ankyrin-Binding Integral Proteins Define Early Developmental Intermediates |journal=J Neurosci |date=1997 |volume=17 |issue=18 |pages=7025–7036 |doi=10.1523/JNEUROSCI.17-18-07025.1997 |pmid=9278538 |pmc=6573274 }}</ref> At the same time, the periaxonal extension of the glial cell wraps around the axon, giving rise to the paranodal regions.  This movement along the axon contributes significantly to the overall formation of the nodes of Ranvier by permitting heminodes formed at the edges of neighboring glial cells to fuse into complete nodes.
Septate-like junctions form at the paranodes with the enrichment of NF155 in glial paranodal loops.  
[[File:Nodes of Ranvier.png|thumb|Nodes of Ranvier in the Central and Peripheral Nervous Systems]]
Immediately following the early differentiation of the nodal and paranodal regions, potassium channels, Caspr2 and TAG1 accumulate in the juxta-paranodal regions. This accumulation coincides directly with the formation of compact myelin. In mature nodal regions, interactions with the intracellular proteins appear vital for the stability of all nodal regions.  In the CNS, [[oligodendrocytes]] do not possess microvilli, but appear capable to initiate the clustering of some axonal proteins through secreted factors.  The combined effects of such factors with the subsequent movements generated by the wrapping of oligodendrocyte periaxonal extension could account for the organization of CNS nodes of Ranvier.