Navigation Links
Many causes for learning lags in tumor disorder
Date:12/21/2012

The causes of learning problems associated with an inherited brain tumor disorder are much more complex than scientists had anticipated, researchers at Washington University School of Medicine in St. Louis report.

The disorder, neurofibromatosis 1 (NF1), is among the most common inherited pediatric brain cancer syndromes. Children born with NF1 can develop low-grade brain tumors, but their most common problems are learning and attention difficulties.

"While one of our top priorities is halting tumor growth, it's also important to ensure that these children don't have the added challenges of living with learning and behavioral problems," says senior author David H. Gutmann, MD, PhD, the Donald O. Schnuck Family Professor of Neurology. "Our results suggest that learning problems in these patients can be caused by more than one factor. Successful treatment depends on identifying the biological reasons underlying the problems seen in individual patients with NF1."

The study appears online in Annals of Neurology.

According to Gutmann, who is director of the Washington University Neurofibromatosis Center, scientists are divided when considering the basis for NF1-associated learning abnormalities and attention deficits.

Mutations in the Nf1 gene can disrupt normal regulation of an important protein called RAS in the hippocampus, a brain region critical for learning. Initial work from other investigators had shown that increased RAS activity due to defective Nf1 gene function impairs memory and attention in some Nf1 mouse models.

However, earlier studies by Gutmann and collaborator David F. Wozniak, PhD, research professor in psychiatry, showed that a mutation in the Nf1 gene lowers levels of dopamine, a neurotransmitter involved in attention. In this Nf1 mouse model, Gutmann and his colleagues found that the branches of dopamine-producing nerve cells were unusually short, limiting their ability to make and distribute dopamine and leading to reduced attention in those mice.

The new research suggests that both sides may be right.

In the latest study, postdoctoral fellow Kelly Diggs-Andrews, PhD, found that the branches of dopamine-producing nerve cells that normally extend into the hippocampus are shorter in Nf1 mice. As a result, dopamine levels are lower in that part of the brain.

Charles F. Zorumski, MD, the Samuel B. Guze Professor and head of the Department of Psychiatry, showed that the low dopamine levels disrupts the ability of nerve cells in the hippocampus to modulate the way they communicate with each other. These communication adjustments are a primary way the brain creates memories.

Researchers then found that giving Nf1 mice L-DOPA, which increases dopamine levels, restored their nerve cell branch lengths to normal and corrected the hippocampal communication defect. L-DOPA also eliminated the memory and learning deficits in these mice.

"These results and the earlier findings suggest that there are a variety of ways that NF1 may cause cognitive dysfunction in people," Gutmann says. "Some may have problems caused only by increased RAS function, others may be having problems attributable to reduced dopamine, and a third group may be having difficulties caused by both RAS and dopamine abnormalities."

To customize patient therapy, Gutmann and his colleagues are now working to develop ways to quantify the contributions of dopamine and RAS to NF1-related learning disorders.


'/>"/>

Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
Source:Eurekalert

Related medicine news :

1. Study reveals how cancer drug causes diabetic-like state
2. What Causes Hot Flashes, Anyway?
3. No Proof That Gum Disease Causes Heart Disease, Experts Say
4. A new Achilles heel in fungus that causes dandruff
5. Cone beam CT proves better for visualizing some causes of hearing loss at half the radiation dose
6. Infection Causes 1 in 6 Cancers Worldwide: Study
7. Pneumonia and preterm birth complications are the leading causes of childhood death
8. Scientists discover gene which causes rare disease in babies
9. 3-center study identifies main causes of unprofessional behavior among hospitalists
10. Obesity, depression found to be root causes of daytime sleepiness
11. Food elimination diet identifies causes of difficulty swallowing and swelling of the throat
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/25/2016)... (PRWEB) , ... May 25, 2016 , ... ... in Central Michigan, has produced another video highlighting one of the many supplemental ... Arts class. Sensei Ed Taylor, a 5 th Degree Black Belt in the ...
(Date:5/25/2016)... ... May 25, 2016 , ... ... Program (KOHP), a $500,000 two-year pilot initiative to improve oral health-related awareness, education, ... professional development for health care providers and promote best practices in 10 New ...
(Date:5/25/2016)... MA (PRWEB) , ... May 25, 2016 , ... ... Research Institute (WCRI) compare outcomes of injured workers across 15 states. The ... to work, earnings recovery, access to medical care, and satisfaction with medical care. ...
(Date:5/25/2016)... ... ... Cheryl Bowker of Bowker Insurance Group has been presented with one of the ... ran one of Allstate’s most successful agencies for 48 years, but it was his ... award named for him is not given every year, but only when an agency ...
(Date:5/25/2016)... Puerto Vallarta, Mexico (PRWEB) , ... May 25, 2016 , ... ... menu surrounding the restorative properties of precious stones to complement its new wellness ... spread over two floors and feature a plethora of special services and insuite amenities, ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)... , May 24, 2016 ... beide primären Endpunkte und ... Überlegenheit in ‚ausgezeichneter plus guter ... Colons    ,      (Logo: ... gab heute neue positive Daten von der MORA-Studie ...
(Date:5/24/2016)... 24, 2016 Celsion Corporation (NASDAQ: ... today provided an update on its ongoing OVATION ... combining GEN-1, the Company,s DNA-based immunotherapy, with the ... patients with advanced ovarian cancer who will undergo ... is an IL-12 DNA plasmid vector formulated as ...
(Date:5/24/2016)... , May 24, 2016 Open ... in Clinical Neurophysiology  Elsevier , a ... and services, today announced the launch of ... access journal that focuses on clinical practice issues in ... reports, clinical series, normal values and didactic reviews. It ...
Breaking Medicine Technology: