Study Sheds Light On The Blood-Brain Barrier Mechanism

Blood-Brain Barrier Mechanism

Researchers at the University of Copenhagen have discovered that the blood-brain barrier plays a key role in maintaining glutamate balance . The study, which has recently been published in the journal GLIA Scientific, uncovers a glutamate balance mechanism unknown until now to scientists.

Researchers have discovered the new mechanism while trying to see how the amino acids enter the brain. Dr. Birger Brodina emphasizes that medical breakthroughs are unintentional and that unexpected results can lead to scientific breakthrough.

Glutamate is a major excitatory neurotransmitter in the brain. Glutamate is involved in various processes such as learning, memory and brain development, neuronal plasticity, long-term potential. Also, it is believed that glutamate is involved in the pathophysiology of schizophrenia. This neurotransmitter mediates information transfer from hippocampus to the anterior cingulate cortex and frontal neocortex. One of glutamate receptors is NMDA (N-methyl D-aspartate).

Blood Brain Barrier

Glutamate is extremely important in the pathophysiology of the nervous system, but in certain concentrations. This neurotransmitter is synthesized from glucose and other precursors in nervous cells, such as astrocytes. If the concentration exceeds a certain limit, glutamate becomes toxic. An imbalance of glutamate concentration can be observed in ischemic strokes, namely excitotoxicity, which occurs due to glutamate accumulation in the brain, leading to nerve cell death. Excitotoxicity leads to an influx of calcium into the cell, with the onset of enzymatic processes that lead to cell death. Neuronal injury can be attenuated by administering glutamate receptors inhibitors. This is one of the mechanisms of action that can be targeted in order to develop new treatment options for stroke.

Until now, it was believed that glutamate balance is maintained by various central nervous system cells, but now researchers have discovered that blood-brain barrier plays an important role in this sense. When glutamate accumulates in excess, the blood-brain barrier dumps the excess into the bloodstream where it has no harmful effects. The blood-brain barrier, which is completely separate from the rest of the blood flow is a barrier between the bloodstream and central nervous system, which helps maintain brain homeostasis. This is basically a filter barrier that prevents the penetration of certain toxic substances into the brain tissue.

Experiments involving blood-brain barrier were also performed in the past. Several years ago, using  nerve cells from mice and calves, researchers at the Faculty of Health and Medical Sciences have created an artificial blood-brain barrier. Nevertheless, the results were not very promising as most drugs tested to treat various nervous disorders could not penetrate that barrier. Therefore, in-depth knowledge of how it works is crucial in order to develop new potentials