In article <4gkmfc$t9f at bigblue.oit.unc.edu>,
David Parsons <dparsons at med.unc.edu> wrote:
>>I want to mark an extracellular recording site at the end of an experiment
>elctrochemical deposition of Fe ions from the tip of the elctrode (a fine
>colour (was it with K ferricyanide?, a Prussion blue reaction I think).
We've done electrical stimulation in rat through chronically implanted
stainless steel electrodes and lesioned with about 400 - 800 uA for 10 sec.
This is probably much higher than you'd like to use though. To see the
placement we used a solution of K-Ferrocyanide, K-Ferricyanide and some
kind of acid.
I can't remember the details right now but I'll get a reference
for you. It was in a text written by Gallistel on electrophysiological
methods I think.
This was added to the perfusate (formalin) and simply perfused
intra-cardially. The site shows up as a bright blue-green dot. It's pretty
nifty. We used to have trouble locating lesion sites near the edge of the
brain even at such high currents but this made it much easier.
>Also, can it be done in both whole mounts (cleared or not) and sections?
I believe it could easily be done in both.
Brian Scott | "They are in you and in me; they created us,
bscott at spine.med.utoronto.ca | body and mind; and their preservation is
Department of Physiology | the ultimate rationale for our existence."
University of Toronto, Canada | - Richard Dawkins (The Selfish Gene)