In the nervous system, dopamine acts as a neurotransmitter with roles in motor control, motivation, arousal, cognition, and reward. The mesolimbic pathway is the main pathway associated with reward, and the dopaminergic neurons of this pathway are found in the substantia nigra (SNc) and ventral tegmental area (VTA) of the midbrain. Dopamine acts on different G protein-coupled receptor subtyes. The D1-class (D1 and D5) receptors stimulate cAMP production by activating adenylyl cyclase, which activates the reward pathway. The D2-class (D2, D3, and D4) subtypes act oppositely, inhibiting cAMP production by inhibiting adenylyl cyclase. The differing distributions of the receptor subtypes mean that complex outputs often produce a synergistic effect, despite the receptor subtypes having opposite molecular effects (PMID: 20925949, 21303898).

Dopamine Activation of Neurological Reward System References