Understanding Frankenhaeuser Huxley (FH)

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aupi
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Understanding Frankenhaeuser Huxley (FH)

Post by aupi » Fri Oct 14, 2011 2:28 am

Hello!

I am new to the neuron simulation environment

I am currently having difficulty understanding the FH program on modelDB.
There seems to be some discrepancies between the leakage reversal potential in the actual paper and the program in modelDB.

The discrepancy seems to be quite large with the paper indicating that the reversal potential should be 0.026mV and the modelDB program using the value -69.74mV.

What’s interesting is that even with such a discrepancy the modelDB program outputs the same graphs as those in the paper.

I have also tried simulating the equations in matlab but to no avail as I'm getting stability issues even with robust algorithms such as ODE15s. The gating variables don’t seem to want to turn to the correct directions.

Any help would be greatly appreciated.

Matlab Simulation Graph:
Image

FH ModelDB:
http://senselab.med.yale.edu/modeldb/Sh ... model=3507

FH Original Paper:
http://jp.physoc.org/content/171/2/302.full.pdf

ted
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Re: Understanding Frankenhaeuser Huxley (FH)

Post by ted » Fri Oct 14, 2011 1:25 pm

aupi wrote:discrepancies between the leakage reversal potential in the actual paper and the program in modelDB.

The discrepancy seems to be quite large with the paper indicating that the reversal potential should be 0.026mV and the modelDB program using the value -69.74mV.

What’s interesting is that even with such a discrepancy the modelDB program outputs the same graphs as those in the paper.
Good question, and good to see that you have been actively investigating this. The answer is almost at hand. What variable is plotted in F&H Fig. 1, and what variable is plotted in the graph generated by NEURON that shows the spike? What initial value did F&H assume for V in their model (see p. 306), and what was the initial value of v in the NEURON implementation of their model? If you read the papers by Hodgkin and Huxley, do you recall how they dealt with the fact that spikes arise from a nonzero resting potential? The leakage reversal potential discrepancy contains a hint.

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