It's been a pleasure and a privilege, going to really miss working with you and with the rest of the lab!

Ah nice, that's a good trick

Good tips! The only thing I dislike about this workflow is that the ai file with links is no longer self-contained, so harder to share with collaborators. I usually go straight for multi-panel in python (using Gridspec), and only use illustrator for adding the panel letters

Q: In current clamp, does the delivered current get filtered by Rs?

A: No, the current is truly a square step with accurate amplitude and timing (as long as you don’t saturate the op-amp). The main source of error here is the current leaking out through a bad seal.

Q: In V-clamp (without compensation), does the cell membrane charge up slowly according to the membrane timeconstant tau=Rm*Cm?

A: No, the membrane charges up slowly according to tau=Rs*Cm, i.e. the speed of charging depends on *series resistance (Rs)*, not the membrane/leak resistance Rm.

Q: The pipette capacitance (Cp) causes an RC filtering/transient. Does “R” here refer to the pipette resistance? Will smaller pipette opening affect the capacitive artifact?

A: No, the R here is neither the Rs nor Rleak. It is the sum or resistances in *series* with Cp (e.g. junction resistance)

Q: Does access R affect the recorded voltage in current clamp if I'm not injecting current?

A: There is no DC error if you are not passing current, but the waveform is still affected by the pipette capacitance (tau=Rs*Cp), making fast events like APs smaller and wider

And here are some more FAQs ((I encourage students to not take my word for it, but verify these things for yourself with the simulator!):

Here are a few other great resources I came across while building this:
www.billconnelly.net?p=310
swharden.com/blog/2020-10...
www.bio.ens.psl.eu/~barbour/

Here is the link to the simulator if any of you want to play with it. Or share it with your students if they are learning about electrophysiology!
tinyurl.com/patch-clamp-...

I added sliders to let you easily play around with all the key variables (series/access R, Rs, capacitance comp, etc)

Electronics can be pretty unintuitive. I've found that being able to directly see and manipulate all the variables in a "white-box" system like this makes it much easier to grok what is going on under the hood. Active learning ftw!

On the other hand, Rs compensation in Voltage Clamp is an active circuit that directly drives the cell voltage higher (so it's very important to get it right online!)

Because of the positive feedback loop (command voltage driven by recorded current), it is prone to unstable oscillations.

For example, does bridge balance compensation affects how much current is being delivered to the cell?

Answer: no, bridge balance is a cosmetic DC correction to the recorded voltage (proportional to delivered current). It doesn't influence anything about the actual pipette/cell/injected current

Many students (and practitioners!) get confused about how series resistance, pipette capacitance, and various electronic compensation circuits affect your recordings.

Now you can see for yourself in the simulator!
tinyurl.com/patch-clamp-...