> From: Joao Paulo Carvalho <[log in to unmask]>
> Subject: Re: The Blockade Hypothesis in PD
> Hi Alastair,
>
> I am not suggesting that the cause are blood flow restrictions.
> I am afraid I was not quite clear in given emphasis that the hearth blood flux
> is an analogy with the flux of the neurotransmitters in the brain.One must
> keep in mind that they are different types of fluxes through different types
> of ways or vias.Only a crude analogy.
>
> Another crude analogy one may think of the brain neurotransmitters flux could
> be done with the flux of the messages in the Internet using the
> Internet's Servers providers in the the world net.
> If some servers are blocked the messages
> are directed to others more distant and this will make the messages to arrive
>
> with some delay to his final destination.
> The delay in the case of the flux of the neurotransmitters could bring
> important consequences to the point to cause movement disorder such as tremors
> etc.
>
> I shall end saying that I do appreciate your work and contributions to defeat
> our common enemy PD.
>
Hi Joao
Sorry I misunderstood you . I have never heard this idea before
that there might be some sort of blockage in the transport of the dopamine
from the cells that are producing the dopamine to the brain cells that
are using the dopamine to pass electrical messages .
This idea has at least two merits .
1) Bradyskinesia is explained . When there was a big demand for
dopamine the blockage would cause a progresive depletion of dopamine
at the nerve cell end of the transport system .
2) Dopamine producing cells would die off because there would be an
apparent supplus of dopamine around the dopamine producing cells .
However before we can progress with this idea one has to establish
the method of dopamine transport and the reason for the
blockage/restriction . The normal view is that the dopamine
transports from producing cells to nerve cells by simple diffusion .
It is difficult to imagine a blockage in this system . But I will
gladly consider other suggestions .
The next thing to consider is the action of L-dopa on the dopamine
blockage . Presumably L-dopa would increase the dopamine production
putting more pressure on the blockage/restriction and at some point
thr blockage/restriction fails producing the characteristic sudden off-on
effect . As the dopamine production drops the blockage reasserts
itself producing the sudden on-off effect .
Until we get a cure for PD it is important to look and test any
idea . This idea has merits but it is too imprecise in its description
of the method of dopamine transportation and blockage for me to propose any
method by which this idea could be tested . All modifications and
improvements to the above please post .
peace
Alastair ( [log in to unmask] )
