The Blood-Brain Barrier (BBB)

The Blood-Brain Barrier (BBB)

 1. More than 100 years ago it was discovered that if blue dye was injected into the bloodstream of an animal, that tissues of the whole body EXCEPT the brain and spinal cord would turn blue. To explain this, scientists thought that a "Blood-Brain-Barrier" (BBB) which prevents materials from the blood from entering the brain existed. More recently, scientists have discovered much more about the structure and function of the BBB.

 2. The blood-brain barrier safeguards over 400 miles of capillaries and blood vessels in the brain.

 3. The Blood-brain barrier is semi-permeable; that is, it allows some materials to cross, but prevents others from crossing.

 4. Tumors in the brain pose a particular problem, since most regular cancer drugs cannot cross the barrier.

 5. The Blood-brain barrier consists of the endothelial cells lining the blood vessels in the brain. These fortress cells are glued together very tightly and, in contrast to other organs and tissues, there are no chinks between them for blood-borne materials to leak into brain tissue.

 6. A molecular Trojan horse can sneak drugs like Glial Derived Neurotrophic Factor (GDNF) across the barrier.
GDNF is a potent neurotrophin that can revive damaged nerves in animal models of Parkinson's disease; it's also a potential therapy for stroke and drug addiction.

 7. Neurotoxins such as Botulinum in the food might affect peripheral nerves, but the blood–brain barrier can often prevent such toxins from reaching the central nervous system, where they could cause serious or fatal damage.

 8. The blood-brain barrier protects the brain from unwanted chemicals in the blood, but presents a huge challenge for getting drugs into the brain. New strategies for delivering molecules across the barrier should open doors for treating diseases like Alzheimer's and Parkinson's.

Know more: http://en.wikipedia.org/wiki/Blood%E2%80%93brain_barrier

Read about Johns Hopkins BBB working group here:
http://bloodbrainbarrier.jhu.edu/about/