AP pacing protocol

Question

hello, i want to pace my cell with a serie of 10 AP-waveform  of the same shape (i recorded one shape as Vm(t) early), how can i do it in openCarp, is there some openCarp command that i can use or  a way to modify the cell model , so that Vm can be clamp and only  takes value from the file with the shape of AP that i have recorded early?

Answer 1

Hi,

You can do this on bench. If you run bench --help you will see the following:

Clamps:
      --clamp-SVs=STRING       colon separated list of state variable to clamp
                                 (default=`')
      --SV-clamp-files=STRING  : separated list of files from which to read
                                 state variables  (default=`')
      --SV-I-trigger           apply SV clamps at each current stim
                                 (default=on)
      --AP-clamp-file=STRING   action potential trace applied at each stimulus
                                 (default=`')

The last option is the one you need.

Cheers,

T

Comments

my file --AP-clamp-files contains  the trace of one beat(Vm(t)), but when I use this command (bench --numstim 10 --stim-curr 0 --stim-start 0 --stim-dur 1 --bcl 400  --duration 4000 --AP-clamp-file   vm3_imp.txt  --dt 0.02 --SV-I-trigger on --load-module ./GPVm.so  --imp-par=RA=0,AF=1,factor_kiCa=0.5, N 0 --read-ini-file 'limite.sv')
only the first beat have the shape of the given beat, the others 9 beats have 2 different shapes(large and short) , i tryed to reapeat the value of Vm(t) ten times in theclamp file and applied it on the cell, i still have AP with different shapes, I mean with alternances instead of having just 10 beats with the same shape, is there anything wrong in my command ?

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I imagine that your file is just one AP. Your file must be 10 AP so that the voltage can be clamped during the whole simulation. What you can do is take this single AP trace and append it several times until you have a single file that has the duration of the whole simulation and 10 AP.

Cheers,
T

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i tryed it, in the Ap file I reapeat the AP value 10 times, and the colone time was changing,  --stim-curr 0 , but i still have alternances