Dopamine News and Research

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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. Dopamine has many functions in the brain, including important roles in behavior and cognition, motor activity, motivation and reward, inhibition of prolactin production (involved in lactation), sleep, mood, attention, and learning. Dopaminergic neurons (i.e., neurons whose primary neurotransmitter is dopamine) are present chiefly in the ventral tegmental area (VTA) of the midbrain, substantia nigra pars compacta, and arcuate nucleus of the hypothalamus.

Methamphetamine enters brain quickly and lingers

Using positron emission tomography (PET) to track tracer doses of methamphetamine in humans' brains, scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory find that the addictive and long-lasting effects of this increasingly prevalent drug can be explained in part by its pharmacokinetics - the rate at which it enters and clears the brain, and its distribution.

13 Oct 2008

Women who smoke at risk for major depression

A new study by Australian scientists has revealed that women who smoke are at greater risk of developing a major depressive disorder.

1 Oct 2008

Study questions use of newer antipsychotic drugs in children

A new study has found that older antipsychotic drugs are as effective as newer ones for some children.

16 Sep 2008

Abuse of painkillers can predispose adolescents to lifelong addiction

No child aspires to a lifetime of addiction. But their brains might. In new research to appear online in the journal Neuropsychopharmacology today, Rockefeller University researchers reveal that adolescent brains exposed to the painkiller OxyContin can sustain lifelong and permanent changes in their reward system - changes that increase the drug's euphoric properties and make such adolescents more vulnerable to the drug's effects later in adulthood.

10 Sep 2008

Diazepam effects nerve cells in the brain reward system

Addictions to medicines and drugs are thought to develop over a relatively long period of time. The process involves both structural and functional changes in brain nerve cells that are still poorly understood.

27 Aug 2008

One night without sleep increases chemical dopamine in the human brain

Because drugs that increase dopamine, like amphetamines, promote wakefulness, the findings offer a potential mechanism explaining how the brain helps people stay awake despite the urge to sleep. However, the study also shows that the increase in dopamine cannot compensate for the cognitive deficits caused by sleep deprivation.

19 Aug 2008

Being outdoors good for children's eyesight

Australian researchers have found that children who spend the most time outdoors are least likely to suffer from myopia.

13 Aug 2008

Dopamine and Parkinson's

Parkinson's disease and drug addiction are polar opposite diseases, but both depend upon dopamine in the brain. Parkinson's patients don't have enough of it; drug addicts get too much of it. Although the importance of dopamine in these disorders has been well known, the way it works has been a mystery.

10 Aug 2008

COMT gene variation affects fear processing, anxiety

Inborn differences may help explain why trauma gives some people bad memories and others the nightmare of post-traumatic stress. Scientists in Germany and the United States have reported evidence linking genes to anxious behavior. The findings appear in the August issue of Behavioral Neuroscience, published by the American Psychological Association.

10 Aug 2008

Obesity predisposition linked to brain's reward system

The tendency toward obesity is directly related to the brain system that is involved in food reward and addictive behaviors, according to a new study. Researchers at Tufts University School of Medicine (TUSM) and colleagues have demonstrated a link between a predisposition to obesity and defective dopamine signaling in the mesolimbic system in rats.

29 Jul 2008

How anti-depressants and cocaine interact with brain

In a first, scientists from Weill Cornell Medical College and Columbia University Medical Center have described the specifics of how brain cells process antidepressant drugs, cocaine and amphetamines. These novel findings could prove useful in the development of more targeted medication therapies for a host of psychiatric diseases, most notably in the area of addiction.

28 Jul 2008

Genetic mechanisms at play in blood cells important in Parkinson’s disease

What does the genetics of blood cells have to do with brain cells related to Parkinson's disease? From an unusual collaboration of neurologists and a pharmacologist comes the surprising answer: Genetic mechanisms at play in blood cells also control a gene and protein that cause Parkinson's disease.

21 Jul 2008

Virus injection could offer long term relief for Parkinson's

Gene therapy could offer a new, long-lasting way to treat Parkinson's disease, research results announced Tuesday 15 July at FENS 2008 suggest. Dr Deniz Kirik of the University of Lund in Sweden has been using viruses to insert a new combination of genes into animals' brains, where they help produce the dopamine that is lacking in Parkinson's disease. The results suggest the treatment is very effective in animal models for several months, possibly years.

15 Jul 2008

Nicotine clues for dementia treatment

A team of London scientists have found clues for the potentially therapeutic benefits of nicotine on learning, memory and attention while minimising the risk of addiction. The research announced in Geneva Monday will assist the search for new drugs for dementia.

14 Jul 2008

Brain switch provides clues to drug addiction

In the quest to find the biological route of drug addiction, research at Cambridge University, UK, is revealing what makes some people more vulnerable than others. Speaking at Europe's major neuroscience conference in Geneva, Professor Barry Everitt described what they now believe causes the switch from occasional, 'recreational' use to a compulsive habit.

14 Jul 2008

The good and bad side of dopamine

The chemical dopamine induces both desire and dread, according to new animal research in the July 9 issue of The Journal of Neuroscience. Although dopamine is well known to motivate animals and people to seek positive rewards, the study indicates that it also can promote negative feelings like fear.

9 Jul 2008

Genetic change in dopamine transporter supports a role for dopamine signaling in ADHD

A genetic change in the dopamine transporter - one of the brain's dopamine-handling proteins - makes it behave as if amphetamine is present and "run backward," Vanderbilt University Medical Center investigators report this week in The Journal of Neuroscience.

9 Jul 2008

A baby's smile gives mothers a natural high

Scientists say the baby's smile that brightens a mother day also lights up a part of her brain.

8 Jul 2008

Warning about use of psychiatric drugs with the elderly

Health officials in the U.S. are warning doctors that prescribing certain psychiatric drugs to elderly people suffering from dementia can increase their risk of death.

17 Jun 2008

Antipsychotic drugs get FDA label changes

The U.S. Food and Drug Administration today exercised its new authority under the Food and Drug Administration Amendments Act of 2007 (FDAAA) to require manufacturers of "conventional" antipsychotic drugs to make safety-related changes to prescribing information, or labeling, to warn about an increased risk of death associated with the off-label use of these drugs to treat behavioral problems in older people with dementia.

16 Jun 2008