A1 receptor

The adenosine A1 receptor is part of a group of G protein-coupled receptors that hyperpolarize cells and either inhibit or promote adenylyl activity and thus production of cAMP. A1 receptors inhibit adenylyl. A1 receptors are implicated in sleep promotion. They act by inhibiting wake promoting cholinergic neurons in the basal forebrain. A1 receptors are also present in smooth tissues throughout the vascular system as well as the adrenal gland.