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A Unified Frequency Domain Model to Study the Effect of Demyelination on Axonal Conduction.

Chaubey S, Goodwin SJ - Biomed Eng Comput Biol (2016)

Bottom Line: The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach.Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled.Using this approach, future studies can model the loss of myelin in various parts of nervous system.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA.

ABSTRACT
Multiple sclerosis is a disease caused by demyelination of nerve fibers. In order to determine the loss of signal with the percentage of demyelination, we need to develop models that can simulate this effect. Existing time-based models does not provide a method to determine the influences of demyelination based on simulation results. Our goal is to develop a system identification approach to generate a transfer function in the frequency domain. The idea is to create a unified modeling approach for neural action potential propagation along the length of an axon containing number of Nodes of Ranvier (N). A system identification approach has been used to identify a transfer function of the classical Hodgkin-Huxley equations for membrane voltage potential. Using this approach, we model cable properties and signal propagation along the length of the axon with N node myelination. MATLAB/Simulink platform is used to analyze an N node-myelinated neuronal axon. The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach. Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled. Using this approach, future studies can model the loss of myelin in various parts of nervous system.

No MeSH data available.


Related in: MedlinePlus

Simulated variation of action potential velocity vs Node of Ranvier. (A) The case when the length of axon is fixed. (B) The case when distance between inter nodes is constant.
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f7-becb-7-2016-019: Simulated variation of action potential velocity vs Node of Ranvier. (A) The case when the length of axon is fixed. (B) The case when distance between inter nodes is constant.

Mentions: The simulation for this study has been done using the MATLAB and Simulink models following the framework that has been formulated in the “Time Domain Vs Frequency Domain” and “Proposed Modeling—Architecture” sections. Figure 7 shows the simulated variation of AP velocity vs Node of Ranvier (N). This is achieved by the Simulink modeling of a single nerve fiber with a cascade of N nodes (based on the transfer function as derived in the “Time Domain Vs Frequency Domain” section). From Figure 7A, we can see that if we keep the length of the fiber fixed,8 then there is an improvement in the AP conduction velocity. But as N becomes large, there are diminishing returns. Thus, we can always predict an optimum Nodes of Ranvier, N, which will help us to get maximum conduction velocity. From the set of parameter values listed in Table 1, we conclude the optimum N value to be 8.


A Unified Frequency Domain Model to Study the Effect of Demyelination on Axonal Conduction.

Chaubey S, Goodwin SJ - Biomed Eng Comput Biol (2016)

Simulated variation of action potential velocity vs Node of Ranvier. (A) The case when the length of axon is fixed. (B) The case when distance between inter nodes is constant.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4836623&req=5

f7-becb-7-2016-019: Simulated variation of action potential velocity vs Node of Ranvier. (A) The case when the length of axon is fixed. (B) The case when distance between inter nodes is constant.
Mentions: The simulation for this study has been done using the MATLAB and Simulink models following the framework that has been formulated in the “Time Domain Vs Frequency Domain” and “Proposed Modeling—Architecture” sections. Figure 7 shows the simulated variation of AP velocity vs Node of Ranvier (N). This is achieved by the Simulink modeling of a single nerve fiber with a cascade of N nodes (based on the transfer function as derived in the “Time Domain Vs Frequency Domain” section). From Figure 7A, we can see that if we keep the length of the fiber fixed,8 then there is an improvement in the AP conduction velocity. But as N becomes large, there are diminishing returns. Thus, we can always predict an optimum Nodes of Ranvier, N, which will help us to get maximum conduction velocity. From the set of parameter values listed in Table 1, we conclude the optimum N value to be 8.

Bottom Line: The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach.Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled.Using this approach, future studies can model the loss of myelin in various parts of nervous system.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA.

ABSTRACT
Multiple sclerosis is a disease caused by demyelination of nerve fibers. In order to determine the loss of signal with the percentage of demyelination, we need to develop models that can simulate this effect. Existing time-based models does not provide a method to determine the influences of demyelination based on simulation results. Our goal is to develop a system identification approach to generate a transfer function in the frequency domain. The idea is to create a unified modeling approach for neural action potential propagation along the length of an axon containing number of Nodes of Ranvier (N). A system identification approach has been used to identify a transfer function of the classical Hodgkin-Huxley equations for membrane voltage potential. Using this approach, we model cable properties and signal propagation along the length of the axon with N node myelination. MATLAB/Simulink platform is used to analyze an N node-myelinated neuronal axon. The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach. Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled. Using this approach, future studies can model the loss of myelin in various parts of nervous system.

No MeSH data available.


Related in: MedlinePlus