AMPA-type glutamate receptor and Kainate-type glutamate receptor (AMPA receptor (AMPAR), Kainate receptor (KAR))

AMPA and kainate glutamate receptors are two distinct classes of ionotropic glutamate receptors that function as tetrameric ligand-gated ion channels in the central nervous system. These receptors mediate rapid excitatory synaptic transmission by allowing the flux of sodium and, in specific subunit compositions, calcium ions upon activation by glutamate. AMPA receptors are responsible for the majority of fast postsynaptic excitatory transmission and are critical to basic neural signaling, learning, and memory. Kainate receptors, while less prevalent, modulate both pre- and postsynaptic aspects of neurotransmission, contribute to synaptic plasticity, and are implicated in numerous neurological and psychiatric diseases. Both AMPA and kainate receptors are assembled as tetramers using distinct subunits encoded by the GRIA and GRIK gene families, respectively. Their function can be modulated by endogenous and synthetic ligands, with antagonism showing anti-epileptic potential and positive modulation of kainate receptors being a current topic in experimental therapeutics. Excessive activation of these receptors contributes to excitotoxic neuronal damage seen in stroke, epilepsy, and neurodegeneration.

Other names

AMPA receptorAMPARα-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptorGluA receptorGRIA receptorKainate receptorKARKainic acid receptorGluK receptorGRIK receptorIonotropic glutamate receptors (iGluRs)

Antagonists block glutamate binding or channel opening, inhibiting excitatory neurotransmission. Positive allosteric modulators prolong activation or prevent desensitization of kainate receptors. Negative allosteric modulators decrease channel activity. Channel blockers block ion conductance after receptor activation. Agonists activate the receptors directly (generally used for research).