Document Detail


A computer simulation of conduction in demyelinated nerve fibres.
MedLine Citation:
PMID:  4675037     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. The theoretical effects of demyelination on conduction of a propagated impulse have been examined in a computer simulated myelinated nerve fibre. Demyelination was simulated by increasing the capacitance and conductance of the myelin sheath of individual internodes or parts of internodes.2. Internodal conduction time increased as myelin thickness was decreased. The increase in internodal conduction time became more precipitous as the myelin became thinner. Propagation continued past a single demyelinated internode until myelin thickness was uniformly reduced to less than 2.7% of normal myelin thickness.3. Paranodal demyelination was more effective in slowing impulse conduction than was uniform demyelination of an entire internode with an equivalent rise in overall internodal capacitance and conductance.4. The effects on conduction of demyelination of two adjacent internodes or of two internodes separated by a normal internode were more than the sum of the effects of demyelination of each internode individually.5. Propagation across a severely demyelinated internode was blocked with an increase in internal sodium concentration which had a trivial effect on conduction in a normal fibre.6. Propagation across a severely demyelinated internode was blocked with increased temperature at a temperature at which propagation proceeds normally across normal internodes.7. The similarity between the findings of the computer simulations and the experimental findings in demyelinated fibres is discussed.
Authors:
Z J Koles; M Rasminsky
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of physiology     Volume:  227     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1972 Dec 
Date Detail:
Created Date:  1973-03-13     Completed Date:  1973-03-13     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  351-64     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Action Potentials
Amphibians
Animals
Axons / physiology*
Computers
Mammals
Models, Neurological*
Myelin Sheath / physiology*
Neural Conduction*
Ranvier's Nodes / physiology
Sodium / physiology
Temperature
Chemical
Reg. No./Substance:
7440-23-5/Sodium
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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