BIOPSYCHOLOGY SEMINAR
TOPIC: BLOOD BRAIN BARRIER, NEURAL CONDUCTION AND SYNAPTIC TRANSMISSION
BLOOD-BRAIN BARRIER
HISTORY:
The blood brain barrier was discovered by the German scientist Paul Ehrlich who observed that intravenous injection of dyes into the body stained almost all organs except the brain. He believed that this was because the brain just didn't take up the dyes. Then in an experiment in 1913, Edwin Goldmann, who was one of Ehrlich's students, injected dye directly into the spinal fluid and observed that the brain did stain, but the rest of the body's organs did not. This demonstrated that there was some kind of compartmentalization between the bloodstream and the cerebrospinal fluid. Although, it had not yet been observed. It was the neurophysiologist Lina Stern who came up with the concept of the blood-brain barrier in 1921. She had been puzzled by the fact that medicines and serums injected into the body did not reach the brain, and came to the conclusion that there must be a special filter to protect the organ; she called it the "hematoencephalic barrier."
WHAT IS BLOOD BRAIN BARRIER?
A semipermeable membrane seperating the blood from the cerebrospinal fluid, and constituting a barrier to the passage of cells , particles and large molecules. It is a protective network of blood vessels and cells that filters blood flowing to the brain. Blood Brain Barrier is a membrane that controls the passage of substances from the blood into the central nervous system.It is a physical barrier between the local blood vessels and most part of the central nervous system itself, and stops many substances from travelling across it.
ANATOMY OF BLOOD-BRAIN BARRIER
The BBB is semi-permeable; that is, it allows some materials to cross, but prevents others from crossing.
In most parts of the body, the smallest blood vessels, called capillaries, are lined with