GABA-B is a type of receptor in the brain that responds to the neurotransmitter gamma-aminobutyric acid (GABA). It plays a crucial role in inhibiting nerve activity, helping to regulate mood, anxiety, and muscle relaxation. When GABA binds to these receptors, it can lead to calming effects on the nervous system. These receptors are part of a larger family of GABA receptors, which also includes GABA-A receptors. GABA-B receptors are unique because they are metabotropic, meaning they work through a different mechanism than the ionotropic GABA-A receptors. This distinction allows GABA-B to influence various cellular processes and contribute to the overall balance of excitatory and inhibitory signals in the brain.