What is the structure of the GABA-A receptor?

The GABA-A receptor is a crucial component in mediating the effects of the neurotransmitter GABA (gamma-aminobutyric acid), which is the primary inhibitory neurotransmitter in the central nervous system. The structure of the GABA-A receptor is important for its function, as it dictates how the receptor interacts with GABA and other modulators.

The correct structure consists of two alpha subunits, two beta subunits, and one gamma subunit. This pentameric arrangement allows for the formation of a central chloride ion channel, which opens upon binding of GABA. The presence of two alpha and two beta subunits contributes to the receptor's pharmacological properties and its responsiveness to various drugs, such as benzodiazepines and barbiturates. The gamma subunit interacts with these drugs, further influencing their activity and efficacy.

Understanding this specific subunit composition is critical for grasping how the GABA-A receptor operates and contributes to inhibitory neurotransmission. Additionally, variations in the stoichiometry of these subunits can lead to different receptor isoforms, which may have distinct functional roles in neurotransmission and drug action.