Developmental clustering of ion channels at and near the node of Ranvier.
Voltage-gated Na(+) and K(+) channels are localized to distinct subcellular domains in mammalian myelinated nerve fibers. Specifically, Na(+) channels are clustered in high densities at nodes of Ranvier, while K(+) channels are found in juxtaparanodal zones just beyond regions of axoglial contact where sequential layers of the myelin sheath terminate. Specific targeting, clustering, and maintenance of these channels in their respective domains are essential to achieve high conduction velocities of action potential propagation. The cellular, molecular, and developmental mechanisms that exist to achieve this neuronal specialization are discussed and reviewed. Current evidence points to a prominent role in channel clustering played by myelinating glial cells, and sites of axoglial contact in particular.
Rasband
M N
MN
Department of Biochemistry and Cell Biology, State University of New York at Stony Brook, Stony Brook, New York 11794-5215, USA.
Trimmer
J S
JS
D000818:Animals; D007473:Ion Channels; D051379:Mice; D009474:Neurons / Q000737:chemistry / Q000502:physiology*; D015221:Potassium Channels / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011901:Ranvier's Nodes / Q000737:chemistry / Q000502:physiology*; D051381:Rats; D015398:Signal Transduction; D015222:Sodium Channels / Q000737:chemistry
D007473:Ion Channels; D015221:Potassium Channels; D015222:Sodium Channels