increase in electrode resistance

ken kpaulc at [remove]earthlink.net
Wed Mar 24 07:06:07 EST 2004


"Elizabeth Thomas" <ethomas at ulg.ac.be> wrote in message
news:1987c6fa.0403240256.c32ceee at posting.google.com...
> I am currently doing sharp electrode current clamp recordings on
> thalamic slices.  I have an intermittent problem (but it occurs with
> high frequency) with the recordings that has been bothering me.  When
> I start out with the electrodes in the bath, I can start at very
> reasonable resistances like 90-120 Mohms.  But once I penetrate a
> neuron and stablize it with hyperpolarizing currents - the resistance
> climbs up very high to more than 300 MOhms.  At this point it is no
> longer possible for me to continue the experiment.
>
> This problem only occurs after I have penetrated a neuron.  The
> resistance is stable even when I leave the electrode in the bath for a
> long time.  I also have the impression that the problem is very
> reduced during lunch hour.

Wow! Folks get 'angry' with me when I reply to
posts like yours, but it's Fun to do so, so I do.

This out-to-lunch consideration is what 'grabbed'-me.

It's almost as if some other equipment, somewhere
[in the building where your Lab is located?] is in-
jecting a 'signal' into the building's electrical circuitry,
and an 'effect' of that is showing-up at your electrode.

Fascinating.

>
> Has anyone had this problem before?  Any suggestions?

Would it be possible to set up your Experiment
at some place that's far-removed from your Lab?

ken

>
> Sincerely
>
> Elizabeth





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