GABABreseptorit

GABAB Receptor

GABAB receptors are type of metabotropic receptors that mediate the inhibitory neurotransmission of the neurotransmitter GABA (gamma-aminobutyric acid). They are the secondary targets of GABA in the central nervous system. Unlike GABAA receptors, which are ionotropic receptors, GABAB receptors are coupled to G-proteins and activate downstream signaling pathways.

GABAB receptors are heterodimers consisting of two subunits, GABAB1 and GABAB2. The GABAB1 subunit contains the ligand-binding domain and the G-protein coupling domain, while the GABAB2 subunit provides anchoring and additional regulatory functions. The receptor has a long intracellular C-terminus that mediates its signaling effects.

Activation of GABAB receptors leads to decreased neuronal excitability and reduced release of excitatory neurotransmitters. This occurs through the activation of potassium channels and inhibition of voltage-dependent calcium channels. The receptors have been implicated in a variety of physiological processes, including learning and memory, motor control, and resting membrane potential maintenance.

Multiple subtypes of GABAB receptors exist, each having distinct distribution and function in the brain. These subtypes include the GABAB1/GABAB2 combination, as well as combinations with other proteins such as Homer. Research has shown that GABAB receptors are involved in the treatment of neurological and psychiatric disorders, including Alzheimer's disease, Parkinson's disease, and anxiety and depression.

While the exact mechanisms of GABAB receptor function remain to be elucidated, research continues to yield important insights into their role in human health and disease.