L-glutamate is the major excitatory neurotransmitter in the central nervous system and activates both ionotropic and metabotropic glutamate receptors. The metabotropic glutamate receptors are a family of G protein-coupled receptors, that have been divided into 3 groups. The Glutamate Receptor, Metabotropic, 1, (mGluR1 alpha) activates phospholipase C and participates in the central action of glutamate in the central nervous system, such as long-term potentiation in the hippocampus and long-term depression in the cerebellum.