Ron
I can't believe I missed this thread. VERY interesting stuff. I am sure you already know about this, but the Fox Foundation is doing research on the BBB:

from Michael F. Fox website - News:

The other project will use PET imaging to compare the blood brain barrier of people with Parkinson's disease to those who do not have the disease. It is hypothesized that biochemical changes that occur in the blood brain barrier of people with Parkinson's could allow greater accumulation of environmental toxins in the brain. If researchers are able to quantify these changes they may be able to identify people with the disease early and to track disease progression, as well as enable the targeted development of therapies that may restore normal blood brain barrier function.
http://michaeljfox.org/newsEvents_mj...icle.cfm?ID=80

I hope they make some headway on this.
Peg