Glutamate is in an important neurotransmitter that plays a role in learning and memory and is vital to the functioning of the brain. Most people know the word “glutamate” as part of the phrase, “monosodium glutamate,” a flavor enhancer associated with Chinese food. Monosodium glutamate was discovered in Japan in 1907, and identified as the substance that produces a distinct flavor, called umami, found in seaweed. In a human body, however, glutamate plays a role in cellular metabolism and it is the most abundant excitatory neurotransmitter. Excitatory neurotransmitters stimulate the brain, while inhibitory ones facilitate calmness and balance. Glutamate is involved in most brain functions, including cognition, memory and learning. Scientists discovered it as an abundant chemical in the brain over 70 years ago, but only recently identified it as a neurotransmitter. Glutamate is stored in small sacs in neurons (nerve cells) and remains inactive until a nerve impulse triggers its release. It then flows into receptor cells specialized to receive only glutamate. Malfunction of glutamate neurotransmission is related to memory diseases such as Alzheimer’s, and seizure disorders such as epilepsy. Glutamate functioning is also associated with stroke, autism, mental retardation, and lathyrism. Glutamate blockers are drugs that control seizure disorders. They are prescribed only if other drugs do not work, because glutamate blockers can cause serious side effects, such as hallucinations.