Gamma-aminobutyric acid type A receptor subunit rho (GABRR) (GABRR)

The Gamma-aminobutyric acid type A receptor subunit rho, formerly known as the GABA-C receptor, is a ligand-gated chloride channel that mediates slow, sustained inhibitory neurotransmission (IUPHAR/BPS Guide to Pharmacology, 2023). It is distinguished from other GABA-A receptors by its unique pharmacology, notably its insensitivity to benzodiazepines, barbiturates, and bicuculline (PubMed PMID: 11511333). These receptors are most prominently expressed in the retina, where they are essential for fine-tuning visual signal processing and contrast sensitivity (UniProt P24046). In the central nervous system, they contribute to the regulation of the sleep-wake cycle, memory formation, and the modulation of pain signals in the spinal cord (PubMed PMID: 22103918). Because of their localized expression and distinct physiological properties, they are considered promising targets for treating myopia, insomnia, and chronic pain (PubMed PMID: 25503379). However, therapeutic development must address the risk of visual disturbances due to the receptor's high density in the eye.

Other names

GABA-C receptorGABRRRho-type GABA receptorGABRR1GABRR2GABRR3

The GABA-A-rho receptor acts as a ligand-gated ion channel that, upon activation by gamma-aminobutyric acid (GABA), facilitates the influx of chloride ions into the postsynaptic neuron. This influx leads to membrane hyperpolarization, which reduces neuronal excitability and inhibits the generation of action potentials (PubMed PMID: 22103918). Unlike other GABA-A receptors, rho-containing receptors exhibit slow activation and deactivation kinetics, providing a sustained inhibitory current that is particularly important for signal integration in the retina (IUPHAR/BPS Guide to Pharmacology, 2023).