Cl or gluconate in pipette solution?

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EGC's picture
Cl or gluconate in pipette solution?

I will record mEPSI and may also mIPSI on CA1 and CA3. I found that KCl internal is easier to patch than K-Glu. But I was told that minis shouldn't be recorded with Cl-based solution. What will KCl affect the measurement? Is there other anions better than gluconate? Thanks.

Fraser Moss
Fraser Moss's picture
You use pipettes filled with

You use pipettes filled with Kgluconate to study glutamatergic excitatory postsynaptic currents, EPSCs, to elimiate/reduce chloride by replacing Cl- with an impermeant anion so as to eliminate contributions from inhibitory Cl- currents.  You will probabaly also have bicuculline (50 µM) in the bath too to eliminate GABA currents.
You use KCl, to study GABAergic inhibitory postsynaptic currents, IPSCs because the main ion gated by GABA channels is Cl-
When recording minis you should also check (through pharmacology) to see if the cell type you are recording from has any acetycholine or glycine mediated events.