5 July 2008, at 13:24
Dopamine is a hormone and neurotransmitter occurring in a wide
variety of animals, including both vertebrates and invertebrates.
In the brain, this phenethylamine functions as a neurotransmitter,
activating the five types of dopamine receptors — D1, D2, D3, D4
and D5, and their variants. Dopamine is produced in several areas
of the brain, including the substantia nigra and the ventral
tegmental area. Dopamine is also a neurohormone released by the
hypothalamus. Its main function as a hormone is to inhibit the
release of prolactin from the anterior lobe of the pituitary.