GABAreceptor

The GABA receptor is a type of ion channel that is activated by the neurotransmitter GABA (gamma-aminobutyric acid). GABA receptors are widely distributed throughout the central nervous system and play a crucial role in regulating neuronal excitability. They are classified into two main subtypes: ionotropic and metabotropic receptors.

Ionotropic GABA receptors are further divided into two subtypes: GABA(A) and GABA(C). GABA(A) receptors are the most abundant and are composed of a pentameric assembly of five subunits, each of which is encoded by a distinct gene. These receptors are ligand-gated ion channels that open in response to GABA binding, allowing chloride ions to flow into the neuron, thereby hyperpolarizing the cell and inhibiting neuronal activity. GABA(C) receptors, on the other hand, are also pentameric but are distinct from GABA(A) receptors in their subunit composition and functional properties.

Metabotropic GABA receptors, also known as GABA(B) receptors, are G-protein-coupled receptors that mediate their effects through the activation of intracellular signaling pathways rather than through direct ion channel opening. GABA(B) receptors are heterodimeric and are composed of a GABA(B1) subunit and a GABA(B2) subunit. Activation of GABA(B) receptors leads to the inhibition of adenylyl cyclase, resulting in a decrease in cyclic AMP levels and the subsequent inhibition of neuronal activity.

GABA receptors are important targets for the treatment of various neurological and psychiatric disorders, including anxiety, epilepsy, and schizophrenia. Modulation of GABA receptor function has been shown to have therapeutic potential in these conditions, and several drugs that target GABA receptors are currently in clinical use.