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Ramped current injection

Posted: Tue Aug 23, 2005 8:16 am
by bono
I'm trying to create a ramped current injection protocol. I want to simulate a ramp between 0 and 10 pA of current at a rate of 0.1 pA/sec.

I found this in the help file: "Time varying current stimuli can be simulated by setting del=0, amp=1e9 and playing a vector into amp with the play Vector method." (http://www.neuron.yale.edu/neuron/stati ... tml#IClamp).

I read through the play vector file (http://www.neuron.yale.edu/neuron/stati ... .html#play), but I don't understand the syntax or parameters needed to simulate what I want to do.

Can anyone guide me through this?

Cheers.

Re: Ramped current injection

Posted: Tue Aug 23, 2005 10:25 am
by Raj
Another link to try:
http://www.neuron.yale.edu/neuron/stati ... bforc.html

I vaguely remembered seeing your problem solved in a tutorial, the link above to "Model Control: Arbitrary forcing functions" is that tutorial.

Arbitrary forcing functions for current and voltage clamp

Posted: Tue Aug 23, 2005 11:59 am
by ted
Thanks, Raj. Here's a bit more info.

There's a link to a demo in the FAQ list--go to
http://www.neuron.yale.edu/neuron/docs
and click on
FAQ
Look for the item
SEClamp and IClamp just deliver rectangular step waveforms. How can I make them produce an arbitrary waveform, e.g. something that I calculated or recorded from a real cell?

An aside: Vector play with interpolation (5th form listed in the Programmer's
Reference documentation of Vector play) is probably the most convenient
approach, if all you need is a ramp. It also avoids "step" artifacts if you're
using adaptive integration. The elements in the time Vector should have the
values
0
tstart
tfin
and the elements in the vsrc Vector should have the values
y0
y0
yfin

Posted: Wed Aug 24, 2005 9:02 am
by bono
Thanks for the help. It was just what I was looking for!

Cheers!