Metabotropic glutamate receptors (mGluRs) belong to the super family of G-protein coupled receptors (seven transmembrane proteins). mGluRs are further divided into subfamilies: group I mGluRs (mGluR1 and mGluR5) which couple to Gq, thereby activating phospholipase C (PLC). Group II which include mGluR2 and mGluR3 couple to Gi, therefore inhibit the formation of adenylate cyclase. mGluR4, 6, 7, 8 which belong to group III also inhibit adenylate cyclase formation by coupling to Gi¹.

The C-terminus of these receptors has important functions in modulating their activity. This region is important for G-protein coupling, post-translational modifications like phosphorylation as well as protein-protein interactions. The C-terminal region is also subject to alternative splicing². Indeed, mGluR7 can be detected as five different splice variants³.

Like all group III metabotropic glutamate receptors, mGluR7 is localized presynaptically. It is highly expressed in the central nervous system and could also be detected in some peripheral organs like hair cells and spiral ganglion cells of the inner ear³.

As opposed to other group III metabotropic glutamate receptors, mGluR7 has very low affinity for its substrate L-glutamate, therefore, only under high synaptic activity is the receptor active. This enables the receptor to act as a negative feedback loop by inhibiting the release of L-glutamate^3,4.
mGluR7 may play a molecular role in the pathways leading to emotion and cognition⁴.