Type: Catecholamine
Receptors: D1–D5 (all metabotropic)
Region-specific functions:

• Mesolimbic pathway (VTA → nucleus accumbens): Reward, motivation, addiction

• Mesocortical (VTA → prefrontal cortex): Cognitive flexibility, working memory

• Nigrostriatal (substantia nigra → striatum): Movement initiation and control (degeneration → Parkinson’s)

• Tuberoinfundibular (hypothalamus → pituitary): Inhibits prolactin release

• Dysfunction → schizophrenia, Parkinson’s, ADHD