Hello. My name is Norman Saunders.
I run a research laboratory in the University of Melbourne in Australia.
This is the second of 2 talks on barrier mechanisms in the developing brain.
In the first talk I said that I would deal with 2 hypotheses,
which are shown in this next slide.
The first hypothesis is that the brain develops within a well controlled internal environment
that is determined by mechanisms in brain barrier interfaces.
And the second hypothesis is that disturbance of brain barrier mechanisms in the embryo
may have immediate or long-term consequences for brain development
and may underlie some developmental and adult neurological disorders.
In that first talk I dealt mainly with the first hypothesis.
In this second talk I shall give you additional information,
much of it only recently published, which bears on the notion
that the brain develops within a well controlled internal environment.
I'd like to begin with an update on the information that I gave you in that first talk
about the integrity of tight junctions in blood vessels in the developing brain.
This slide is a reminder of the main barrier interfaces in the adult and developing brain.
In addition to the morphological evidence outlined in the first talk,
there is now molecular evidence which reinforces the finding
that tight junctions in the blood-brain and blood-CSF barriers
are functionally effective even in the embryo and neonate.
Molecular expression studies of Daneman and his colleagues in Stanford University
have shown that the junctional proteins occludin and numerous claudins
are expressed in postnatal mouse cerebral blood vessels within a few days of birth,
and that's illustrated in the next slide.