Gamma-aminobutyric acid receptor subunit rho (GABA₊-ρ receptor)

The **gamma-aminobutyric acid A-rho (GABA₊-rho) receptor**, formerly known as the **GABA₌ receptor**, is a subclass of ionotropic gamma‑aminobutyric acid type A receptors composed entirely of rho subunits. These pentameric ligand-gated chloride channels mediate fast synaptic inhibition by allowing chloride ions into neurons upon activation by their endogenous ligand, gamma‑aminobutyric acid (GABA). Unlike typical heteromeric GABAA receptors containing α/β/γ/δ subunits—which are sensitive to benzodiazepines—the rho-subunit–containing forms exhibit unique pharmacology characterized by insensitivity to many classic modulators such as benzodiazepines and barbiturates. They are most abundantly expressed in the retina but also found elsewhere in the brain. Their primary physiological role involves mediating sustained inhibitory currents crucial for visual signal processing; dysfunction or mutation can contribute to retinal diseases such as retinitis pigmentosa[4][5][6].

Other names

GABAA-rho receptorGABAC receptor (deprecated)Gamma-aminobutyric acid type C receptorRho subunit-containing GABAA receptors

Drugs targeting this molecule typically act by: Agonists open chloride channels upon binding, leading to hyperpolarization and neuronal inhibition. Antagonists block chloride influx, reducing inhibitory signaling. These mechanisms underlie their effects on visual processing and general CNS inhibition.