Transmembrane AMPA receptor regulatory protein gamma-8-associated alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor complex (TARPγ8-AMPAR complex)

The TARPγ8-associated AMPA receptor complex is a specialized form of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, where the ion channel is co-assembled with the auxiliary subunit Transmembrane AMPAR Regulatory Protein gamma-8 (TARPγ8) (1.1.1, 1.2.2). This complex is predominantly expressed in the forebrain, particularly the hippocampus, and plays a critical role in mediating fast excitatory neurotransmission and synaptic plasticity (1.2.1, 1.2.5). Because TARPγ8 is absent from the cerebellum—where TARPγ2 (stargazin) is the primary auxiliary subunit—targeting this specific complex allows for the development of precision medicines that modulate hippocampal excitability without the dose-limiting motor side effects, such as ataxia and dizziness, seen with non-selective AMPA receptor antagonists like perampanel (1.1.2, 1.3.2). Therapeutic candidates like RAP-219 and LY3130481 act as negative allosteric modulators (NAMs) that bind to a unique pocket at the interface of the receptor and the TARPγ8 subunit (1.2.3, 1.4.3). These drugs are currently being investigated for the treatment of focal epilepsy and chronic pain, offering a neuroanatomically specific approach to managing central nervous system disorders (1.3.4, 1.4.3).

Other names

CACNG8-associated AMPA receptorTARP gamma-8-associated AMPARGluA1/2-gamma-8 receptor complexTARPγ8-associated AMPAR

Negative allosteric modulation (NAM) specifically at the interface between the TARPγ8 auxiliary subunit and the AMPA receptor core subunits (GluA1-4).