Corporate Banner
Satellite Banner
Genomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Genetic Mutation Could Increase Understanding of ADHD

Published: Wednesday, November 27, 2013
Last Updated: Wednesday, November 27, 2013
Bookmark and Share
Absence of normal gene that expresses a protein involved in nerve cell communication results in seizures and hyperactivity.

Scientists at Trinity College Dublin have discovered that a mutation in a single gene involved in the functioning of the brain’s nervous system can lead to hyperactivity symptoms that are characteristic of Attention-Deficit Hyperactivity Disorder (ADHD).

Getting the nervous system wired up properly is a big job. The brain contains billions of different types of nerve cells, which all have to be connected in a very precise fashion. This circuitry self-assembles as an embryo grows, based on a developmental programme involving the actions of thousands of different genes.

The scientists discovered that a mutation in a single mouse gene, ‘Elfn1’, can have a big effect. Their new findings give impetus to discover whether mutations in Elfn1 in humans can give rise to similar symptoms and whether they might play a part in some patients with epilepsy and ADHD. These two conditions occur together far more often than expected by chance.

In an article just published in the international journal, PLOS ONE, Associate Professor in Genetics at Trinity, Kevin Mitchell, and Research Technical Officer, Dr Jackie Dolan, investigated the importance of the function played by Elfn1 and the protein it produces when expressed. They did this by experimentally removing it from some mice and comparing the effects against those seen in mice with the normal gene.

Although overall brain anatomy and patterns of connectivity remained normal, there was clear evidence of disturbance in brain function in individuals without Elfn1. Seizures occurred in some, and these became more common over time and were easily triggered by human interaction. Secondly, hyperactivity was observed, and this showed an unusual response to the stimulant, amphetamine.

Amphetamine normally causes hyperactivity in animals that have Elfn1 present, as it does in most humans. Here, it reduced the hyperactivity of the mice without the gene. This is similar to the situation in patients with ADHD, where amphetamine and related drugs have a paradoxical, calming effect. “These findings clearly show that removal of the Elfn1 gene affects brain circuits with multiple consequences for behaviour,” said Dr Dolan.

The seizures likely relate to the function of Elfn1 in dampening the response of the nervous system to strong stimuli in key brain structures called the cortex and hippocampus. However, the development of ADHD-like hyperactivity focused on a different brain structure, known as the habenula. This structure is part of a system that integrates information from multiple regions of the brain and regulates the activity of nerve cells that produce mood-regulating chemicals such as dopamine and serotonin.

Professor Mitchell said: “We are at the beginning of this process of figuring out how this gene works and understanding the consequences when it is mutated. But, these animals provide a unique model to investigate how subtle changes in brain development can ultimately result in aberrant brain function”.

Elfn1 was first discovered by Dr Dolan, Professor Mitchell and colleagues in 2007. The protein it produces when expressed allows communication from one nerve cell to another. In a study published in Science last year, Emily Sylwestrak and Anirvan Ghosh, of the University of California, San Diego, showed that the Elfn1 protein determined what kind of connection was made onto those nerve cells.

The new research, which was funded by Science Foundation Ireland, is available below. 


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,100+ scientific posters on ePosters
  • More than 4,500+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Scientists Discover Genetic Basis for Memory Formation with Implications for Neurological Diseases
Two genes linked to simple memory formation also regulate appropriate nerve responses that are lacking in related disease sufferers.
Monday, December 23, 2013
International Research Project Identifies a New Genetic Mutation that Helps Explain the Development of Eczema
Scientists have identified a new genetic mutation linked to the development of a type of eczema known as atopic dermatitis (AD).
Monday, November 04, 2013
New Genetic Mutation Helps Explain Development of Eczema
Researchers found that a mutation in the gene Matt/Tmem79 led to the development of spontaneous dermatitis in mice.
Monday, November 04, 2013
Scientists Propose a Molecular Explanation for Degenerative Disease
An international collaboration has shed new light on the origins and molecular causes of age related degenerative conditions including Motor Neurone Disease (MND).
Monday, August 19, 2013
Scientific News
Insight into Bacterial Resilience and Antibiotic Targets
Variant of CRISPR technology paired with computerized imaging reveals essential gene networks in bacteria.
Illuminating Hidden Gene Regulators
New super-resolution technique visualizes important role of short-lived enzyme clusters.
Genes That Increase Children's Risk Of Blood Infection Identified
A team led by Oxford University has identified genes that make certain children more susceptible to invasive bacterial infections by performing a large genome-wide association study in African children.
Poverty Marks a Gene, Predicting Depression
New study of high-risk teens reveals a biological pathway for depression.
World’s Largest Coral Gene Database
‘Genetic toolkit’ will help shed light on which species survive climate change.
Early Genetic Changes in Premalignant Colorectal Tissue Identified
Findings point to drivers of early cancer development, targets for cancer prevention therapies.
Scientists Find Evidence That Cancer Can Arise Changes
Researchers at Rockefeller University have found a mutation that affects the proteins that package DNA without changing the DNA itself can cause a rare form of cancer.
Modified Microalgae Converts Sunlight into Valuable Medicine
A special type of microalgae can soon produce valuable chemicals such as cancer treatment drugs and much more just by harnessing energy from the sun.
Breakthrough Approach to Breast Cancer Treatment
Scripps scientists have designed a drug candidate that decreases growth of breast cancer cells.
Loss Of Y Chromosome Increases Risk Of Alzheimer’s
Men with blood cells that do not carry the Y chromosome are at greater risk of being diagnosed with Alzheimer’s disease. This is in addition to an increased risk of death from other causes, including many cancers. These new findings by researchers at Uppsala University could lead to a simple test to identify those at risk of developing Alzheimer’s disease.
Skyscraper Banner

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,100+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,500+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!