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

The Gamma-aminobutyric acid receptor type A subunit rho, historically designated as the GABA-C receptor, is a specialized ionotropic receptor that forms ligand-gated chloride channels primarily expressed in the vertebrate retina, hippocampus, and superior colliculus [1, 5]. It is composed of pentameric rho subunits (GABRR1-3) and is distinguished from classical GABA-A receptors by its unique pharmacology, notably its insensitivity to common allosteric modulators like benzodiazepines, barbiturates, and bicuculline [3, 13]. Biologically, it facilitates slow-onset, sustained inhibitory currents that are essential for processing visual information and modulating sleep-wake cycles [5, 8]. Pathologically, dysfunction or genetic variation in these subunits is linked to visual impairments such as myopia, as well as neuropsychiatric conditions like anxiety, sleep disorders, and epilepsy [1, 12]. Drugs like the selective antagonist TPMPA and the agonist cis-4-aminocrotonic acid (CACA) have been used to study its potential for treating cognitive and visual disorders [1, 5]. Because of its high concentration in the retina, therapeutic development targeting this receptor requires careful monitoring for visual toxicity and retinal signal disruption [1, 8].

Other names

GABA-C receptorGABAC receptorRho-containing GABA receptorIonotropic GABA receptor rhoGABRR1GABRR2GABRR3

The target acts as a ligand-gated ion channel; upon binding of gamma-aminobutyric acid (GABA), the channel conducts chloride ions into the neuron, causing membrane hyperpolarization and providing a slow, sustained inhibitory effect on neuronal excitability [4, 13].