I am not sure where we are going with this thread. Recent replies are useful information, but have little to do with the mode of operation of the BBB.
Also, to get a solution to PD, we must question "established facts". If billions of $ have been spent, and we still don't know
1. what causes PD.
2. How to permanently cure it.
3. How to avoid side effects as bad as the disease.
then some or all of the "established facts" are wrong!!!
vlhperry says,
" Rick, this blows your BBB sky high. If the dopamine cannot get out of the substantia niagra it can't leak out of the brain barrier."
But can we be sure that it is true that dopamine cannot get out of the substantia nigra (not niagra!). Also, I didn't think that Rick had started this thread! LOL
I like the simplest of explanations, there is less to go wrong.
My concept is the BBB is a membrane, through which, substances can pass both ways. The permeability can be made higher or lower. Osmotic pressure drives substances from one side to the other. If a substance is on one side of the membrane, it will diffuse through the membrane until equilibrium is reached. If stress opens the membrane wide, equilibrium will be established fast. The brain is one side, the body and bloodstream is the other side. The body is a much larger mass and has much more blood and fluids than the brain. The body would therefore have much more dopamine than the brain at equilibrium. But dopamine can't cross the BBB (in a normal person), so the brain dopamine is kept in the brain, and movement is normal.
In our case, if the BBB is leaky, there is a strong osmotic pressure to drain it out into the body and bloodstream.
Can it be a coincidence that all the things which make our symptoms worse, stress, old age, pesticides,... all open the pores of the BBB.
Things which improve, curcumin, alpha lipoic acid, CDP choline, GNDF, all close the pores.
Add to this Prof Leenders has shown PWP have defective BBB's.
A recent report states, Though the BBB has been thought to be intact in neurodegenerative illnesses, PD and AD, recent evidence argues otherwise.
This is my point exactly, challenge the "established facts" until they are irrefutable, or modify them until they are irrefutable.
You can give answers to many questions using this concept.
Why is PD predominently an old person's disease.
A. Because the BBB gets more porous with age.
Why does stress cause an immediate worsening of symptoms
A Because it causes a catastrophic opening of the BBB.
There are still questions that can't be answered,
eg Why does eating start dyskinesia? (See a previous thread)
Does operation of the bulbar muscles, which control chewing close the pores of the BBB suddenly and give a temporary high level of dopamine in the brain? It may be a mechanism to prevent the new substances we are eatiing from passing the BBB into the brain, until they have been checked.
We need to research any unanswered questions until we either kill or confirm the concept.
Ron