Dopamine is a chemical substance produced in the body to transmit signals between nerve cells. It is found in parts of the brain responsible for the regulation of movement, balance and walking as well as those involved in memory and learning.
Parkinson’s disease is a condition in which the dopamine-producing cells of the brain gradually deteriorate so that insufficient dopamine is produced. This leads to the muscular tremors or shakes that characterize this disease.
Dopamine levels are also influenced by the use of certain psychoactive drugs such as nicotine, cocaine, amphetamines, and ecstasy.
Source: GreenFacts