Cs stands for the membrane capacitance of neurons; when asked for compensation, the amplifier uses series of small currents to get the Cs values based on tau and membrane resistance. Based on these measurements, extra current is passed during recordings to load the Cs.

This automatic procedure however is run in a way to make sure that Cs is not over-compensated as the latter can cause damage of the membrane and deterioration of the patch quality. Thus, typically upon request for Cs compensation, the Cs is underestimated and under-compensated. This is especially the case with larger neurons.

If your settings are right, you should be able to repeat Cs compensation several times (with no harm) to get the Cs properly compensated yielding good recordings. Hope this helps, SV     

Thank you for your answer, Saak. In most of our recordings, the compensation always fails, no matter how many times we repeat it. Do you have an idea as to why this might be happening? Something wrong with our settings possibly?

check the settings. there should be a folder that contains the parameters given for Cs compensation. Perhaps these are set up incorrectly...

Here's our Cslow protocol. It seems to be the default...

I'll try calibrating the amplifier.

Dear Matheus, it is a long time since you posted this question.

I am having the same issue (very bad Cslow compensation with neurons in slices). Did you by any chance manage to solve the issue?

Thanks!

Diego