Dopamine is a common neurotransmitter produced by and affecting parts and functions of the human brain. It is primarily responsible for behavioral responses but can also affect other aspects of brain function and physiology.

What Is Dopamine?

Dopamine is a chemical produced by the brain that acts as a neurotransmitter. When triggering special receptors, it regulates certain behaviors, perceptions and moods. Dopamine receptors control behavior and perception functions in the brain. The behavioral response is dictated by the amount of dopamine and particular receptor involved.

Where Is Dopamine Found?

In humans, dopamine is found in its highest concentrations in and around the ventral tegmental area, substantia nigra pars compacta and arcuate nucleus of the hypothalamus. Dopamine is also found in other areas at lower doses.

What Is the Function of Dopamine?

Depending on the receptor or combination of receptors involved, dopamine affects a plethora of central nervous system functions, including cognitive ability, voluntary movement, motivation, sex drive, sleep, mood, attention span and comprehension elements of brain function and behavioral response.

Dopamine and Mental Illness

The dopamine receptor gene known as D2 has been identified as a major contributor to the development of schizophrenia. This occurs primarily through a mutation or function failure of the receptor. Paranoia has also been linked to an imbalance of dopamine levels in the brain. Very high and very low dopamine levels can also trigger psychotic episodes.

Dopamine and Addiction

Cocaine and methamphetamines inhibit the uptake of dopamine and provoke its production in the brain, which can result in heightened awareness, hyperactivity, increased sex drive and euphoria. It can also cause significant mental and behavioral disorders, such as hyperactivity, involuntary muscle movements, insomnia, psychosis, paranoia and schizophrenic episodes.

Source:

Encyclopedia.com: Ventral Tegmental Area

Acta Neurobiologiae Experimentals: Dopamine, Learning, and Reward-Seeking Behavior

About.com: The Treatment of Bipolar Disorder---Medications for Mania

More Information:

University of Texas: Dopamine---A Sample Neurotransmitter