Glutamatergic synapse

Glutamate receptors (GluRs) are the major excitatory receptors in the brain and induce depolarization of the postsynaptic membrane following the presynaptic release of glutamate. They can be classified in ionotropic and metabotropic receptors. Ionotropic GluRs are ligand-gated cation channels and can be divided in 3 groups according to their sensitivity to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), Kainate, and N-Methyl-D-aspartic acid (NMDA). AMPA receptors (GluR1-4) evoke fast excitatory postsynaptic potentials while Kainate receptors (GluR5-6 and KA1-2) and NMDA receptors (NR1-3) mediate slower synaptic transmission and exert effects also on synaptic plasticity. Glutamate can modulate neuronal excitability and synaptic transmission also through second messenger signaling pathways; mGluRs are G protein-coupled receptors that function as constitutive dimers and mediate slow synaptic potentials.