Do you have phosphocreatine and ATP in your pipette solution? Here is
a picture of spike -frequency- run down I saw without having them in
the pipette, the run down stopped after I included them (and I needed
both)
http://yfrog.com/3zspikingg
Whole cell CC recording from a substantia nigra pars reticulata
neuron.
On the other hand, I wonder whether whether you should let the spike
amplitude run down... maybe it will stabalize after 20-30 minutes, and
your pipette solution has perfused down the axon.
When I did recording from cerebellar granule cells, I regularly left
them for 10 minutes to let CsCl diffuse.
Oh, and you're sure your SERIES resistance and pipette capacitance is
stable? An increase in series resistance or capacitance could increase
the RC constant and filter out the amplitude of the spike.
On Apr 9, 3:55 pm, Shlomo Dellal <shlomina... from yahoo.com> wrote:
> I'm doing whole-cell recordings (VC and CC) from cerebellar granule cells while trying to evoke antidromic action potentials with a bipolar stimulating electrode placed in the molecular layer. I find that the spike amplitude decreases over the course of 10-15 minutes which is too short a time frame for me to carry out my experiments. I don't think that the neuron is going downhill on me as the holding current and input resistances are holding steady. Has anybody else seen this and what is the most likely cause? Thanks.