Dopamine receptors are a class of G protein-coupled receptors that are activated by the neurotransmitter dopamine, playing a critical role in many neurological processes including motivation, pleasure, cognition, memory, learning, and fine motor control. There are five subtypes of dopamine receptors, D1 through D5, which are divided into two families: D1-like receptors (D1 and D5) that generally stimulate adenylate cyclase, and D2-like receptors (D2, D3, and D4) that generally inhibit it.