Hello Franscesco,

Well, the increase in RS could indeed mask an increase in LTP. Did you notice an increase in the EPSC rise-time that should occur in Rs increases?

Anyway, you cannot correct for it afterwards.

Regards

Fabien

Perhaps you could practice non-STDP experiments to obtain a baseline control under your specific recording conditions, and to get a sense for how variable your recording parameters are? As you can read in most methods sections, standard practice is to abort experiments once recording conditions change (including series resistance, holding current for voltage-clamp, resting membrane potential in current-clamp).

Hi Francesco, I always used pipettes with resistance of 3-3.5MOhm and could get stable recordings upto 2hrs after a tetanus protocol.

regards,

Saju

Hi Francesco,

I agree with Fabien, these experiments are most likely lost. Now there are a couple of things that you can check.

if you repeat your experiment, without the stimulation, do you also see these changes? If yes, you should check your solutions (internal most likely) or see if you don't have any drift of your pipettes. Check also if your slice is correctly fixed in the chamber and if it doesn't get swollen (if your solutions are not correct that might happen and move your cell away from your pipette)

If it doesn't happen without the stim, then you might want to make sure that your stim electrode is not too close from your recorded cell. Also always try to use as less current as you can, cells don't like it usually...

Hope this helps,

Good luck

There is a clear explanation of SR and how it effects currents written by Boris Barbour.

You can find it here.

http://www.biologie.ens.fr/~barbour/