Odd voltage results

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maya
Posts: 6
Joined: Mon Sep 27, 2010 9:10 am

Odd voltage results

Post by maya »

I run a model of a complicated reconstructed cell using nrn7.1 version.
I insert only nseg, e_pas, g_pas, cm, global_ra and celsius and I run the simulation with a voltage graph.

This is a simple simulation, but it results in a crazy voltage graph from the first millisecond: Image.
Changing to other global_ra and celsius parameters causes another very odd voltage graph: Image.


What do you think is wrong?

maya
Posts: 6
Joined: Mon Sep 27, 2010 9:10 am

Re: Odd voltage results

Post by maya »


maya
Posts: 6
Joined: Mon Sep 27, 2010 9:10 am

Update

Post by maya »

After working on this strange phenomenon for 3 days, I found the bug!
One of the many dendrites was actually composed of a couple of the same XYZ location points:

Code: Select all

apic[64] {pt3dclear()
   pt3dadd(-31.1, 253.26, -34.24, 2.07)
   pt3dadd(-31.1, 253.26, -34.24, 2.07)
}
This probably caused Neuron to think this is a circle, and caused an endless loop or something...
Now everything looks normal :)

ted
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Joined: Wed May 18, 2005 4:50 pm
Location: Yale University School of Medicine
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Re: Odd voltage results

Post by ted »

The graphs are very strange and ugly.

The morphology error would produce a section with length 0. I don't know if that is sufficient to account for the results you got; I would expect that NEURON knows how to deal with such model specification errors. Wildly erroneous results can be a symptom of serious problems in one or more mod files. If you would like me to examine your mod files to see if such problems exist, zip them up and email them to ted dot carnevale at yale dot edu

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