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

The TARP gamma-8-dependent AMPA receptor complex is a specialized assembly of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor and the auxiliary subunit transmembrane AMPA receptor regulatory protein (TARP) gamma-8 (encoded by CACNG8) [1.3.2, 1.5.1]. This complex is primarily localized in the forebrain, particularly within the hippocampus, where it mediates fast excitatory neurotransmission and is essential for synaptic plasticity and long-term potentiation [1.3.5, 1.5.2]. Because TARP gamma-8 expression is regionally restricted, this complex serves as a high-precision therapeutic target for neurological disorders such as temporal lobe epilepsy and chronic pain [1.1.3, 1.3.1]. Selective negative allosteric modulators (NAMs), such as LY3130481 (Cevidopram), target the interface between the AMPA receptor and the gamma-8 subunit, allowing for the inhibition of overactive excitatory circuits in the hippocampus while sparing other brain regions like the cerebellum [1.1.1, 1.4.1]. This selectivity significantly reduces the risk of motor side effects, such as ataxia and dizziness, which are common with non-selective AMPA receptor antagonists like perampanel [1.1.3, 1.3.2]. Beyond epilepsy, the complex is being investigated for roles in alcohol use disorder, ADHD, and certain types of glioma [1.2.1, 1.4.2, 1.5.2]. The structural basis for this selectivity involves specific residues in the transmembrane domains of gamma-8 that are not conserved in other TARP family members [1.3.2, 1.4.1]. Therapeutic intervention at this target aims to restore the balance of excitatory signaling in specific neural circuits without the global CNS depression associated with broader glutamate receptor inhibition [1.1.3, 1.3.2].

Other names

TARP gamma-8/AMPA receptor complexCACNG8-associated AMPARgamma-8-containing AMPA receptorgamma-8 TDAA target

Negative allosteric modulation (NAM) of the AMPA receptor complex specifically when associated with the TARP gamma-8 auxiliary subunit