glutamate By Ivan Suarez Robles 07 Feb, 2011 An amino acid precursor. Glutamate is the most common excitatory neurotransmitter in the brain and spinal cord.Related Articles: Glossary: lamotrigineGlossary: excitotoxinsGlossary: magnesium ion (Mg2+)Glossary: memantineGlossary: NMDA receptor