The glutamatergic system as potential clinical biomarkers for blood and cerebrospinal fluid monitoring

Abstract

Glutamate is the most abundant excitatory amino acid in the brain. In addition to the protein structure, it plays important roles in metabolism, nutrition, and signaling via glutamate receptors. Glutamate is synthesized from glutamine by glutaminase, while it is metabolized to the inhibitory amino acid γ-aminobutyric acid (GABA) by glutamic decarboxylase. Thus, the glutamine-glutamate-GABA cycle plays an important role in both excitatory and inhibitory neurotransmissions via glutamate and GABA receptors. Accumulating evidence suggests that abnormalities in glutamatergic neurotransmission via ionotropic and metabotropic glutamate receptors may play crucial roles in the pathophysiology of a variety of psychiatric, neurologic as well as other peripheral disorders. In this chapter, the author discusses the glutamatergic system as potential clinical biomarkers for human blood and cerebrospinal fluid monitoring.