Table 1.
Brief Overview of Glutamatergic Synapse Components: Localization and Function.
| Glutamate synapse components | Localization | Function | References |
|---|---|---|---|
| VGluT | Presynaptic neuron | Packaging glutamate into vesicles | Takamori et al., 2000; Fremeau et al., 2001, 2004 |
| Glutaminase | Presynaptic neuron | Synthesizes glutamate from glutamine | Revett et al., 2013 |
| α7nAChR | Both neurons and glia | Soluble Aβ binding (in low concentrations) triggers Ca2+-dependent release of glutamate from the presynaptic neuron, as well as stimulation of the postsynaptic neuron | Wang et al., 2000b; Gahring et al., 2004; Magdesian et al., 2005; Puzzo et al., 2008; Mura et al., 2012;Hascup and Hascup, 2016 |
| mGluR Group II/III | Pre- and postsynaptic neuron | Gi/o-coupled receptor, inhibition of presynaptic release of glutamate or inhibition of postsynaptic response to stimulation | Ambrosini et al., 1995; Petralia et al., 1996; Ferraguti and Shigemoto, 2006; Rudy et al., 2015 |
| mGluR Group I | Postsynaptic neuron | Gq-coupled receptor, depolarizes neuron upon binding of glutamate and results in Ca2+ release from intracellular stores | Petralia et al., 1996; Ferraguti and Shigemoto, 2006; Revett et al., 2013 |
| AMPA | Pre- and postsynaptic neuron | Presynaptically promotes the formation of synapses. Postsynaptically depolarizes the neuron upon glutamate binding | Wisden and Seeburg, 1993; Isaac et al., 2007; Rudy et al., 2015 |
| NMDA | Postsynaptic neuron | Contains a magnesium block that is removed upon depolarization of postsynaptic membrane, allowing for Ca2+ influx into the neuron | Calabresi et al., 1992; Wisden and Seeburg, 1993; Pandis et al., 2006; Parsons et al., 2007; Rudy et al., 2015 |
| GLT-1 (EAAT1)/GLAST (EAAT2) | Astrocytes | Clearance of glutamate from the synapse by uptake into astrocytes | Lehre et al., 1995; Revett et al., 2013 |
| GS | Astrocytes | Conversion of glutamate to glutamine so that it may be transported back to the presynaptic neuron | Norenberg and Martinez-Hernandez, 1979; Parsons et al., 2007; Revett et al., 2013 |
Note. Outline of glutamate neuronal and astrocytic components and their functions in glutamatergic neurotransmission.
α7nAChR = alpha-7 nicotinic acetylcholine receptor; AMPA = α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid; EAAT = excitatory amino acid transporter; GLAST = glutamate aspartate transporter; GLT-1 = glutamate transporter-1; GS = glutamine synthetase; mGluR = metabotropic glutamate receptor; NMDA = N-methyl-D-aspartic acid; VGluT = vesicular glutamate transporter.