(12)-(14) PNS axons of CST knockout (CSTKO) mice frequently contain degenerated mitochondria in the nodes of Ranvier
. (13) Similar changes were reported in mice with other paranodal abnormalities, (15), (16) suggesting that the paranodal axo-glial junction may be important not only for rapid conduction but also for axonal homeostasis.
[30.] Chiu SY (2011) Matching mitochondria to metabolic needs at nodes of Ranvier
. Neuroscientist 17: 343-350.
For example, Nav1.6 is the variety present at the nodes of Ranvier
, Nav1.5 is in the heart muscle, and others such as Navl.7, Nav1.8 and Nav1.9 are predominant in pain-sensing neurons.
It is suggested that 75% of Na channels need to be inhibited for an effective block to be established in unmyelinated axons, while the blocking of three or more nodes of ranvier
in myelinated axons will produce the desired block (Cox et al 2003).
"The nodes of Ranvier
act like power station relays along the myelin sheath.
Talbot, PhD (Stanford University), and colleagues have developed methods of studying the nodes of Ranvier
In myelinated axons, voltage-gated sodium channels ([Na.sub.v]s) are aggregated in high density at nodes of Ranvier
, while Shaker-type voltage-gated potassium channels ([K.sub.v]1s) are clustered within juxtaparanodal regions and separated from nodal [Na.sub.v]s by septatelike paranodal junctions [49-51].
I explain that the gaps in the second line-up are representative of myelin patches called internodes and the participants are representative of the Nodes of Ranvier
. The quick passing of the object from person to person across the gaps is similar to the "jumping" of action potentials down a myelinated axon.