Featured Research

from universities, journals, and other organizations

Mouse model reveals a cause of ADHD

Date:
March 11, 2010
Source:
Rockefeller University
Summary:
Although it's typically considered an adolescent curse, ADHD actually affects about five percent of adults as well. New research in a mouse model of attention deficit/hyperactivity disorder suggests that the root of the psychiatric disorder might be the over-activity of a protein that regulates dopaminergic pathways. The work suggests a path toward new treatments for symptoms including inattentiveness, over-activity and impulsivity.

Although it's typically considered an adolescent curse, ADHD actually affects about five percent of adults as well. New research in a mouse model of attention deficit/hyperactivity disorder suggests that the root of the psychiatric disorder might be the over-activity of a protein that regulates dopaminergic pathways. The work suggests a path toward new treatments for symptoms including inattentiveness, over-activity and impulsivity.

The cause of ADHD is unknown, but there is increasing evidence that dopamine, a neurotransmitter involved in the brain's reward-motivation system, is involved. Scientists have found that the level of dopamine, and the D2 receptor it binds to, are involved in the progression of ADHD, as well as four connected regions in the frontal region of the brain, two of which are directly linked to reward and motivation.

The Rockefeller University researchers, led by Marc Flajolet, a senior research associate, and Paul Greengard, Vincent Astor Professor and head of the Laboratory of Molecular and Cellular Neuroscience, focused on an enzyme called casein kinase I (CK1), which is involved in regulating the dopamine signaling pathway. The work was published in January in the Proceedings of the National Academy of Sciences.

Flajolet and coauthor Ming-Ming Zhou, a research associate in the lab, created a line of mice genetically modified to overexpress a form of CK1, called CK1δ, specifically in the forebrain of the mouse. Under normal conditions and in response to stimulation by drugs such as the ones used today to treat ADHD, the mice that overexpress CK1δ show behavioral symptoms and responses to drugs similar to those observed in people with ADHD.

"The genetically modified mice that we generated present interesting features such as hyperactivity and altered nesting capacities that might be related to attention deficit, and possibly altered impulsivity," says Flajolet.

To test the nesting capacities, the mice were kept overnight, singly housed in an open field arena, with pressed cotton nesting material. After 24 hours, the scientists compared the overall quality of the nests and the amount of material, if any, that each mouse used to build its nest. The normal mice tore up the pressed cotton and slept in the nests, while the CK1δ-overexpressing mice barely touched the cotton material.

The researchers also found that the CK1δ-overexpressing mice became less hyper in response to amphetamine and methylphenidate (Ritalin) in a way similar to that of ADHD patients. Finally, biochemical studies by Postdoctoral Associate Heike Rebholz showed that both classes of dopamine receptors, D1R and D2R, are significantly reduced in the CK1δ-overexpressing mice, further evidence that the dopaminergic system is severely affected.

"We believe that overexpression of CK1δ induces some developmental steps that resemble what might be happening in ADHD patients and therefore we propose that the CK1δ-overexpressing mice are a model for this disorder," says Flajolet. "It will be interesting to investigate if CK1 could be the origin of developmental defects in humans that lead to ADHD."


Story Source:

The above story is based on materials provided by Rockefeller University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zhou et al. Forebrain overexpression of CK1δ leads to down-regulation of dopamine receptors and altered locomotor activity reminiscent of ADHD. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.0915173107

Cite This Page:

Rockefeller University. "Mouse model reveals a cause of ADHD." ScienceDaily. ScienceDaily, 11 March 2010. <www.sciencedaily.com/releases/2010/02/100227211115.htm>.
Rockefeller University. (2010, March 11). Mouse model reveals a cause of ADHD. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2010/02/100227211115.htm
Rockefeller University. "Mouse model reveals a cause of ADHD." ScienceDaily. www.sciencedaily.com/releases/2010/02/100227211115.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins