The amino acid called glutamic acid performs a major role in the central nervous system as an excitatory neurotransmitter which increases the rate of firing in the synapse of the neurons. Glutamic acid is considered to be a very vital excitatory neurotransmitter in the synapses present in the brain and the spinal cord. This molecule is also an essential chemical precursor of the neurotransmitter called GABA - a major sedative neurotransmitter in the human body. Glutamic acid plays a very important role in the metabolism of sugars and fats in the body. The amino acid is also very important in facilitating the transportation of the essential mineral potassium across the blood brain barrier. Glutamic acid is found in the blood in very high concentrations, however, it is not able to pass across the blood brain barrier as easily as glutamine, but it tends to reach the brain in small amounts due to its abundance in the blood. Glutamic acid is also used as a metabolic fuel by the brain aside from its neuro-transmitting role. One of the main roles played by glutamic acid includes the detoxification of ammonia in the body by picking up free nitrogen atoms in the body, this metabolic process results in the creation of another related amino acid called glutamine. This bio-chemical conversion of glutamic acid into glutamine is the only pathway through which ammonia present in the brain is detoxified and converted into less harmful constituents. Personality disorders can be corrected by glutamic acid and this amino acid is also very helpful in the treatment of childhood behavioral disorders which arise due to bio-chemical imbalances. Glutamic acid is used as a supplement in treating cases of epilepsy, it is also used to treat mental retardation, disorders such as muscular dystrophy, as well as ulcers and cases of hypoglycemic coma, the amino acid is also very useful in the treatment of complications arising from insulin treatment of patients affected by diabetes. Glutamic acid is found in abundance in food sources such as meat and poultry, as well as fish, eggs, and dairy products in common with other amino acids. Glutamic acid is also found in certain protein rich plant food sources. The majority of protein rich food sources are abundant in their glutamic acid content, this is the reason that individual deficiency in glutamic acid is likely to develop only in individuals suffering from protein deficiencies.