Alpha-2A adrenergic receptor

Alpha-2A adrenergic receptors are G protein-coupled receptors primarily found on presynaptic and postsynaptic neurons in the brain, spinal cord, and peripheral tissues. These receptors are composed of seven transmembrane helices and couple to inhibitory G proteins (Gi/Go). Upon activation, they inhibit adenylyl cyclase activity, leading to a decrease in intracellular cyclic AMP levels. This action modulates neurotransmitter release, particularly norepinephrine, and influences neuronal excitability, thereby regulating sympathetic tone, sedation, analgesia, and motor function.