A Structural Specialization at Nodes of Ranvier in the Central Nervous System

Nature ◽  
1966 ◽  
Vol 210 (5037) ◽  
pp. 757-758 ◽  
Author(s):  
R. H. LAATSCH ◽  
W. M. COWAN
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nodes Of Ranvier ◽  
Structural Specialization ◽  
The Central Nervous System

scholarly journals The Structure and Conduction Velocity of the Medullated Nerve Fibres of Prawns

1941 ◽  
Vol 18 (1) ◽  
pp. 50-54 ◽  
Author(s):  
W. HOLMES ◽  
R. J. PUMPHREY ◽  
J. Z. YOUNG
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Conduction Velocity ◽  
Myelin Sheath ◽  
Axon Diameter ◽  
Relative Thickness ◽  
Nodes Of Ranvier ◽  
Nerve Fibres ◽  
The Central Nervous System ◽  
Myelinated Fibres

1. The structure of the myelinated fibres of prawns is described, and the homologies of the nucleated sheath which lies between the axon and the fatty layer discussed. 2. The relative thickness of the myelin sheath increases with decrease in total diameter of the fibre along a curve similar in shape to that found in vertebrates and earthworms. 3. Nodes of Ranvier are found in the sheaths of most fibres of a diameter greater than about 13µ 4. The nodes are similar to those in vertebrate nerves in that the myelin sheath is interrupted at the node. 5. The conduction velocity of fibres in the central nervous system of axon diameter 26µ and total diameter 35µ is between 18 and 23 m. per sec., a rate faster than is found in the "unmyelinated" fibres of similar size in other crustacea.

scholarly journals Glial and neuronal isoforms of Neurofascin have distinct roles in the assembly of nodes of Ranvier in the central nervous system

2008 ◽  
Vol 181 (7) ◽  
pp. 1169-1177 ◽  
Author(s):  
Barbara Zonta ◽  
Steven Tait ◽  
Shona Melrose ◽  
Heather Anderson ◽  
Sheila Harroch ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sodium Channels ◽  
Molecular Mechanisms ◽  
Nerve Impulse ◽  
Node Of Ranvier ◽  
Nodes Of Ranvier ◽  
Additional Function ◽  
The Central Nervous System ◽  
Adhesion Complex

Rapid nerve impulse conduction in myelinated axons requires the concentration of voltage-gated sodium channels at nodes of Ranvier. Myelin-forming oligodendrocytes in the central nervous system (CNS) induce the clustering of sodium channels into nodal complexes flanked by paranodal axoglial junctions. However, the molecular mechanisms for nodal complex assembly in the CNS are unknown. Two isoforms of Neurofascin, neuronal Nfasc186 and glial Nfasc155, are components of the nodal and paranodal complexes, respectively. Neurofascin-null mice have disrupted nodal and paranodal complexes. We show that transgenic Nfasc186 can rescue the nodal complex when expressed in Nfasc−/− mice in the absence of the Nfasc155–Caspr–Contactin adhesion complex. Reconstitution of the axoglial adhesion complex by expressing transgenic Nfasc155 in oligodendrocytes also rescues the nodal complex independently of Nfasc186. Furthermore, the Nfasc155 adhesion complex has an additional function in promoting the migration of myelinating processes along CNS axons. We propose that glial and neuronal Neurofascins have distinct functions in the assembly of the CNS node of Ranvier.

Multiple myelinated branches from nodes of Ranvier in the central nervous system

1972 ◽  
Vol 44 (2) ◽  
pp. 652-655 ◽  
Author(s):  
A.R. Lieberman ◽  
K.E. Webster ◽  
J. S˛pac˛ek
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nodes Of Ranvier ◽  
The Central Nervous System

scholarly journals The Axonal Cytoskeleton and the Assembly of Nodes of Ranvier

2017 ◽  
Vol 24 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Aniket Ghosh ◽  
Diane L. Sherman ◽  
Peter J. Brophy
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Protein Complexes ◽  
Nerve Impulse ◽  
Nodes Of Ranvier ◽  
Axonal Membrane ◽  
Voltage Gated Sodium Channels ◽  
The Central Nervous System ◽  
High Concentrations ◽  
Surface Domains

Vertebrate nervous systems rely on rapid nerve impulse transmission to support their complex functions. Fast conduction depends on ensheathment of nerve axons by myelin-forming glia and the clustering of high concentrations of voltage-gated sodium channels (Nav) in the axonal gaps between myelinated segments. These gaps are the nodes of Ranvier. Depolarization of the axonal membrane initiates the action potential responsible for impulse transmission, and the Nav help ensure that this is restricted to nodes. In the central nervous system, the formation of nodes and the clustering of Nav in nodal complexes is achieved when oligodendrocytes extend their processes and ultimately ensheath axons with myelin. However, the mechanistic relationship between myelination and the formation of nodal complexes is unclear. Here we review recent work in the central nervous system that shows that axons, by assembling distinct cytoskeletal interfaces, are not only active participants in oligodendrocyte process migration but are also significant contributors to the mechanisms by which myelination causes Nav clustering. We also discuss how the segregation of membrane protein complexes through their interaction with distinct cytoskeletal complexes may play a wider role in establishing surface domains in axons.

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