Dear Brian,
  Your thoughtful response arrived at my house and I do apologize for not
getting back to you sooner. There was no other response and I must admit
that there was no serious response to the other question. I passed out your
explanation of "Up-Regulate"to several people including my neurologist who
used the term at my support group's last meeting. But he is on vacation
until next week. When I have at least a couple of responses I will let you
know by posting to the list. I think the term means different things to
different people. One thing to a cancer researcher; another to a neurologist
with no research interests. I searched any number of on-line dictionaries
and could find no listing. Lots of use but no explanation/definition

 I do thank you for your response

Best
  george



At 01:40 AM 7/22/99 +0100, you wrote:
>On Sun 18 Jul, George J. Lussier wrote:
>> Dear Colleagues,
>>    A. What is meant by the term/concept of "up regulate" with regard to PD
>> medications?
>>    B. The days here in New England have been hot and humid and I do a lot of
>> sweating but when the sweat flows into my mouth I can taste no salt. Is
>> there some kind of relationship between salt intake, depletion and how we
feel?
>>
>> thanks....george
>>
>>
>>
>I wrote the attached response to George Lussier's question, but I have not
seen my reply printed back to me as usual.  Has anyone seen this e-mail before ?
>If my note really didn't get printed, what's going on?  Has the Ken & Barb
>show finally taken over, and should we re-name ourselves the Parkinsn Lost?
>
>Bewildered of Derby
>
>This was my original note:
>
>--------------------------------------------------
>>
>There were a lot of answers about question B, but I don't think I saw a
>reply to the question about "Up-regulation".
>
>As far as I know, the following is still the subject of lively debate
>among neurologists, and is by no means an accepted fact.
>
>Up- (and down)-regulation of dopamine
>We know that the production of dopamine is a controlled process,
>dedicated to producing the precise quantity of dopamine where and when it
>is required. This feed-back system is thought to be connected with two
>separate processes:
>Dopamine works by stimulating dopamine receptors on the target neurones.
>These target neurones can sense if their receptops are being over or under-
>stimulated, and regulate the production of receptors (which are being
>made and replaced all the time to compensate for this. This is called
>post-synaptic down (or up)-regulation, and operates over a period of days
>rather than minutes.
>  I see this up- or down-regulation as the means by which the nervous
>system keeps the system in balance, even though the brain is slowly losing
> its complement of dopamine-producing cells.
>  A much faster control system occurs because the neurone which makes
>and releases the the dopamine (the pre-synaptic neurone) also has dopamine
>receptors (called auto-receptors because they sense the amount of dopamine
tthat the neurone has itself released. This information is then used to
>increase or decrease dopamine release, and is effective over short time-
>scales. This auto-receptor system is what i see as the means by which
>the brain  tries to maintain a steady rate of flow of dopamine,
>
>I hope that is understandable: As I said earlier, this has the status of
>'informed speculation'
>----------------------------------------------
>--
>Brian Collins  <[log in to unmask]>
>
>
"It is better to keep your mouth shut and appear stupid than to open it and
remove all doubt."
                                          --Mark Twain