how to plot the IV curve

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xyang

how to plot the IV curve

Post by xyang »

Thanks for the NEURON software, help a lot with my electrophysiology experiment.
I am interested in plotting the IV curve for Na current, is there a way to plot the IV curve?
Thank you very much!
Best,

Xianghong
ted
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Re: how to plot the IV curve

Post by ted »

The term "IV curve" is ambiguous. Sodium current is not just a function of membrane potential--it also depends on time and initial conditions. Please define what kind of IV curve you want--steady state I vs. V, instantaneous I vs. V for a particular holding potential, peak I vs. V for a series of voltage steps from a particular holding potential.
xyang

Re: how to plot the IV curve

Post by xyang »

Hi, Ted:

Thank you very much for your reply!
We are interested in the peak I vs. V for a series of voltage steps (-60 mV to 70 mV with 10 mV steps) from a particular holding potential (-60 mV). We have a TTX sensitive transient Na current in our model.
Best,

Xianghong
ted
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Posts: 5810
Joined: Wed May 18, 2005 4:50 pm
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Re: how to plot the IV curve

Post by ted »

We are interested in the peak I vs. V for a series of voltage steps (-60 mV to 70 mV with 10 mV steps) from a particular holding potential (-60 mV)
Then you need to
1. Create a single compartment model which has your voltage gated current inserted.
2. Write a program that does the following:
Runs a series of simulations in which an SEClamp applies the desired conditioning and test potentials to the model cell, while the Vector class's record method captures the time course of ina.
After each run, uses the Vector class's max or min method to detect the peak ina, and appends this to a Vector called inapeak. Also appends the test potential to another Vector called vvec.
After the very last run has been completed and analyzed, creates a Graph and uses the Vector class's plot method to plot the contents of inapeak vs. vvec (generates a plot of peak ina vs. test potential).
xyang

Re: how to plot the IV curve

Post by xyang »

Thank you, Ted:
That helps!
Best,

Xianghong
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