Developmental Changes in Expression of βIV Spectrin Splice Variants at Axon Initial Segments and Nodes of Ranvier.

Axon initial segments (AIS) and nodes of Ranvier are highly specialized axonal membrane domains enriched in Na channels. These Na channel clusters play essential roles in action potential initiation and propagation. AIS and nodal Na channel complexes are linked to the actin cytoskeleton through βIV spectrin.