Metabotropic glutamate receptors neuron distribution

The excitatoiy amino acids (EAA), glutamate and aspartate, are the principal excitatory neurotransmitters in the brain. They are released by neurons in several distinct anatomical pathways, such as corticofugal projections, but their distribution is practically ubiquitous in the central nervous system. There are both metabotropic and ionotropic EAA receptors. The metabotropic receptors bind glutamate and are labeled mGluRl to mGluRB. They are coupled via G-proteins to phosphoinositide hydrolysis, phospholipase D, and cAMP production. Ionotropic EAA receptors have been divided into three subtypes /V-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole-proprionic acid (AMPA), and kainate receptors (Nakanishi 1992). 

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