ScienCentral News
 
environment general science genetics health and medicine space technology February 16, 2003 
home NOVA News Minutes archive login

is a production of
ScienCentral, Inc.
Making Sense of Science

Also of Interest
Bloody Teeth Boost Memory (video)

What Sex Is Your Brain (video)

Lysins To Kill (video)

M.D. on a Chip (video)

Models of Health (video)

Anger Gene (video)

Modified Mosquitoes (video)

Building Brain Bridges (video)

Watching Living Brains (video)

Worm Fat (video)

Infector Detector (video)

Catching Up On Sleep (video)

Dying To Be Thin (video)

Barflies (video)

Cloned Child (video)

NOVA News Minutes
Visit the NOVA News Minutes archive.
ScienCentral News and Nature
Nature genome promo logo
Don’t miss Enter the Genome
our collaboration with Nature.
Best of the Web!
Popular Science Best of the Web 2000
Selected one of Popular Science’s 50 Best of the Web.
Get Email Updates
Write to us and we will send you an email when a new feature appears on the site.
Maternal Separation (video)
January 28, 2003

Can't see the movie above??
download realplayer logo
You can choose to either view it with a RealPlayer by clicking here. Or get the free QuickTime player to view the higher-quality video above.

Interviewees: Wayne Brake, University of California Santa Barbara and Nora Volkow, Brookhaven National Laboratory.

Video is 1 min 21 sec long. Please be patient while it loads enough to start playing.

Produced by Sanjanthi Velu

Copyright © ScienCentral, Inc.

Also on ScienCentral News

Addicted To Food - Scientists are finding that your nose and eyes could be tricking you into eating more than you want to. (7/12/02)

Your Brain on Drugs - Scientists looking directly at the brains of drug users have found that methamphetamine damages the brain and its effects continue long after people stop using it. (3/6/01)

Elsewhere on the web

Science of Addiction

Pathophysiology of Drug Abuse

Dopamine Transporter’s Involvement in Neuropsychiatric Disorders

There's no substitute for a mother's love.

As this ScienCentral News video reports, neuroscientists have found that when kids are deprived of this love, it could affect the way their brains are wired and make them more prone to abuse drugs as adults.


Mother’s Love: The Anti-Drug?

While many individuals experiment with drugs, only some people become addicted to them, according to Wayne Brake, assistant professor of Neuroscience at the University of California Santa Barbara, and his colleagues Michael Meaney and Alain Gratton at McGill University in Canada.

They also report that previous studies have attributed drug abuse to an abnormal dopamine system in the brain. Dopamine is a brain chemical that is released by certain nerve cells and is associated with feelings of pleasure and reward. Brake says that if the dopamine system is compromised in humans, “it could lead to greater susceptibility for drug dependence and perhaps greater vulnerability to develop certain psychiatric illnesses.”

He also says that studies published in research journals report that those who are abused or neglected as children tend to abuse drugs more often as adults. So in a study published in the journal Pscyhoneuroendocrinology, Wayne and his colleagues speculated that a trauma early in childhood, such as being separated from one’s mother, would affect the dopamine system in the brain.

The researchers decided to test the idea on rats. They separated rat babies from their mothers for several hours a day during the first two weeks of their lives. This evokes stress in the mother who eventually, “spends less time licking and grooming and nursing and caring for her pups”, according to Wayne. Then they waited until the rats were 3 months old, at which time they are considered adults. They tested the rats’ sensitivity to different doses of drugs like cocaine and amphetamine. Wayne says that although all the rats responded to high doses of the drugs, the rats separated from their mothers “were much more responsive or hyper in response to the drugs at lower doses.”

Next, Wayne and his team wanted to know if their theory about dopamine was correct. When they analyzed the brain tissue, they found that the rats separated from their mothers released a lot more dopamine than those that grew up next to mom. According to Wayne, this suggests that the dopamine system in the brain is functioning at a higher level in the rats that were separated from their mothers.

The researchers dug further to find out what was causing this change in dopamine levels and found that the separated animals showed a decrease in a protein in the brain called dopamine transporters.

The system works like this. Dopamine is released into the space between two nerve cells, stimulating the neighboring nerve cell. In normal animals, once the signal has been sent, dopamine is taken back up by the dopamine transporters into the cell from which it was released. This function is called dopamine reuptake. “This,” says Wayne, “is what regulates the amount of dopamine released in the brain and how much motivational drive we have to take drugs”.

When there is a decrease in the amount of dopamine transporters in the brain, the dopamine reuptake does not happen as it normally would. This means the dopamine signals last longer and are stronger than those in normal individuals.

Brake’s team also studied a number of genes in the front part or prefrontal cortex of the rat’s brain. They found that several genes that are involved in the development of the dopamine system were either turned on or off or changed in their expression.

Wayne says all this appears to be regulated by the care a mother gives early in the rat’s life. He explains, “while we don’t know a lot about their (genes) exact nature, we do know that it may be important for generating how the adult brain will be wired later on”.

The team plans to examine the genes individually to confirm the reliability of the changes in the genes and to study their role in brain development.

Brake points out that although we cannot automatically translate the findings in rats to humans, the study does show that in the brains of mammals, a mother’s care is extremely important for brain development.

This study was funded by grants from the National Institute on Drug Abuse, and the Canadian Institutes of Health Research.



by Sanjanthi Velu


About Search Login Help Webmaster
ScienCentral News is a production of ScienCentral, Inc.
in collaboration with the Center for Science and the Media.
248 West 35th St., 17th Fl., NY, NY 10001 USA (212) 244-9577.
The contents of these WWW sites © ScienCentral, 2000-2002. All rights reserved.
The views expressed in this website are not necessarily those of the NSF.
NOVA News Minutes and NOVA are registered trademarks of WGBH Educational Foundation and are being used under license.