When a stroke or head injury releases a flood of the chemical messenger glutamate, the excess glutamate leaves damaged neurons in its wake. Israeli scientist Vivian Teichberg, Ph.D., has developed a new method that may protect the brain from this destruction by harnessing the brain’s natural ability to keep glutamate levels in check.
The human brain is packed with a substance that needs to be treated like a handle-with-care explosive. Glutamate, one of the most abundant chemical messengers in the brain, plays a role in many vital brain functions, such as learning and memory, but it can inflict massive damage if it is accidentally spilled into brain tissue in large amounts.
Glutamate flow in the brain is normally kept in check by a system of dam-like structures, which release a trickle of the substance only when and where it is needed. But burst a dam—as happens in stroke, head trauma, and some other neurological disorders—and the treacherous messenger floods the brain. The surge of glutamate radiates out from the area of original damage, and kills neurons in nearby areas. The expanded damage can leave in its wake signs of impaired brain function, such as slurred speech and shaky movement.
Depending on the severity and location of the stroke or head trauma, recovery can be slow and incomplete. Now new hope is coming from a completely new approach to protecting the brain against the ravages of injury and disease. It consists of “mopping up” excess glutamate by boosting a natural process that the healthy brain already uses to safeguard itself from a glutamate overdose. If this concept is borne out in clinical trials, it might be helpful in treating a variety of acute and chronic brain insults and diseases.
Inside the Glutamate Storm
The amino acid glutamate is the major signaling chemical in nature. All invertebrates (worms, insects, and the like) use glutamate for conveying messages from nerve to muscle. In mammals, glutamate is mainly present in the central nervous system, brain, and spinal cord, where it plays the role of a neuronal messenger, or neurotransmitter. In fact, almost all brain cells use glutamate to exchange messages. Moreover, glutamate can serve as a source of energy for the brain cells when their regular energy supplier, glucose, is lacking. However, when its levels rise too high in the spaces between cells—known as extracellular spaces—glutamate turns its coat to become a toxin that kills neurons.*