Glutumate (or glutamate)

An amino acid derived from the diet.  In certain neurons, it is converted to GABA by an enzymatic reaction that depends on vitamin B6.  Consequently, a severe deficiency in this vitamin can lead to convulsions due to lack of GABA-mediated inhibition in the brain.  This effect was witnessed on a large scale when an artificial milk formula lacking vitamin B6 was put on the market in some developing countries.  Many of the infants developed seizures, which were eradicated when the vitamin deficiency was corrected.  Along with aspartate, it is one of the most prevalent (excitatory) neurotransmitters in brain. 

See Amino acids, Aspartate (or aspartic acid), Attentional deficit hyperactivity disorder (ADHD), Gamma amino butyric acid (GABA), Glycine, Mossy fibers, Neurotransmitters, Oligodendrocytes, Parallel fibers