[Histonet] methylene blue microinjection

[Chana de Wolf]

John,

It is unfortunate, but common, for researchers to refer to sharp
micropipettes as "electrodes." This is probably because they are frequently
placed over electrodes in for stimulation and recording. I think Salim
probably means that he/she is simply using a micropipette for drug injection
(though he/she didn't mention where, and it could very well be a nucleus
rather than a ventricle).

I have frequently used alcian blue for determining accurate placement of
pipettes for microinjection, either in ventricles or nuclei. I can vouch
from experience that this method works excellently, at least in lateral
ventricle (LV) and paraventricular nucleus (PVN).

To determine *electrode* placement, I run current through the electrode to
create a visible lesion.

Sincerely,

Chana de Wolf



On Wed, Jul 8, 2009 at 9:03 AM, John Kiernan <jkiernan <@t> uwo.ca> wrote:

> Dear Salim Yalcin Inan,
>
> You need to explain your question! Electrodes are not ordinarily positioned
> to stimulate or record from the CSF in the ventricles of the brain.
> Methylene blue is soluble in water (see the Merck Index, Conn's Biological
> Stains or any other book about dyes or stains published since about 1885).
> How could injecting a soluble dye into one of the ventricles of the brain
> lead to "validation of drug/electrode injection/placement accuracy"?
>
> Methylene blue is listed in the catalogues of almost all vendors of
> chemicals because this dye has many uses. A Google Scholar search for
> "methylene blue" brings up "about 294,000 hits". You won't get the answers
> you need without doing a proper survey of earlier published literature
> (peer-reviewed papers, scholarly books etc) targeted at the questions you
> are trying to answer.
>
> Your email address shows that you are at a major Canadian university, but
> you don't declare yourself as a professor, postdoc, technician, graduate
> student, summer student, janitor's brush carrier or senior administrator.
> When asking for help you need to say who you are, as well as explain clearly
> what information you need. A well prepared question usually draws several
> answers that are helpful also to other people reading the listserver.
>
> John A. Kiernan
> Department of Anatomy & Cell Biology
> The University of Western Ontario
> London, Canada
> = = =
> ----- Original Message -----
> From: Salim Yalcin Inan <syinan <@t> ucalgary.ca>
> Date: Tuesday, July 7, 2009 16:52
> Subject: [Histonet] methylene blue microinjection
> To: Histonet <histonet <@t> lists.utsouthwestern.edu>
>
> > Dear All,
> >
> >
> >
> > Does anyone use intracerebroventricular methylene blue injection
> > for the
> > validation of drug/electrode injection/placement accuracy?
> >
> > Could you please give me the catalogue number of methylene blue,
> > so I can
> > order for myself? And any other advices would be greatly appreciated.
> >
> > Thank you very much in advance.
> >
> > Salim
> >
> > syinan <@t> ucalgary.ca
> >
> >
> >
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