Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Gene in Mice Controls Risk-Taking Behavior in Humans

Published: Wednesday, September 28, 2005
Last Updated: Wednesday, September 28, 2005
Bookmark and Share
Scientists have studied mice with a single copy of the neuroD2 gene and found they had an impaired ability to form emotional memories and conditioned fear.

Scientists at Fred Hutchinson Cancer Research Center have found that a specific neurodevelopmental gene, called neuroD2, is related to the development of an almond-shaped area of the brain called the amygdala, the brain's emotional seat.

This gene also controls emotional-memory formation and development of the fear response, according to research led by James Olson, M.D., Ph.D., associate member of the Clinical Research Division at the Hutchinson Center.

The findings will be published in the early online edition of the Proceedings of the National Academy of Sciences the week of Sept. 26.

Olson and colleagues studied mice with a single copy of the neuroD2 gene and found they had an impaired ability to form emotional memories and conditioned fear.

“Most of us are familiar with the fact that we can remember things better if those memories are formed at a time when there is a strong emotional impact - times when we are frightened, angry or falling in love,” he said.

“That's called emotional-memory formation. The amygdala is the part of the brain that is responsible for formation of emotional memory.”

In the brain's early development, the neuroD2 gene encodes the neuroD2 protein to transform undifferentiated stem cell-like cells into neurons, or brain cells.

Under the microscope, certain areas of the amygdala were absent in mice with no neuroD2 gene.

In mice with just one copy of neuroD2, researchers also found fewer nerve cells in the amygdala.

Researchers conducted experiments on mice with a single copy of the neuroD2 gene to test the theory that only having one copy of the gene impacts emotional learning and the development of traits such as fear and aggression.

In one experiment, mice were exposed to an adverse stimulus coupled with a non-adverse stimulus, a tone followed by a mild foot shock.

Normal mice crouch down and stop moving the next time they hear the tone, a physiologic response that indicates they expected a shock. The mice remembered the experience.

However, those with a single copy of the neuroD2 gene did not respond to the tone like the normal mice did, researchers found.

These mice did not freeze their movements as often in anticipation of the mild shock.

To assess the level of unconditioned fear in mice with a single copy of the neuroD2 gene, researchers put them into a situation that would elicit a fear response in normal mice.

They used a maze elevated 40 centimeters above a tabletop where mice had the option to walk along narrow, unprotected walkways or arms with protective walls.

Half of the time the neuroD2-deficient mice chose the unprotected arms, whereas the normal mice almost always chose the protected arms, Olson said.

“All of this matches very well with previous observations that the amygdala is responsible for fear, anxiety and aggression,” said Olson.

“Now we're seeing that the neuroD2-deficient mice, when compared to normal littermates, show a profound difference in unconditioned anxiety levels as well as their ability to form emotional memories.”

Olson noted that the dosage of neuroD2, one copy versus the normal two copies, was important for how much fear, anxiety and aggression the mice displayed.

“These findings are new to science,” said Olson, who is also an associate professor in pediatrics at the University of Washington School of Medicine.

“The contribution we have made is showing that neuroD2 is related to the development of the amygdala.”

“This is the first time that a specific neurodevelopmental gene has been related to these emotional activities in the brain.”

Further research is needed that one day could explain why some people react the way they do to fear, or why they take risks, Olson said.

“The question is, are there differences in the neuroD2 gene-coding sequence or differences downstream of the neuroD2 pathway during brain development that could affect either psychiatric or emotional functions in humans?”

“It's a completely unexplored question; it is the immediate next question you would go to if you want to understand how this gene impacts human behavior.”


Further Information
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 2,500+ scientific posters on ePosters
  • More Than 3,800+ 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

Protein-Measurement Technique’s Could Standardize Quantification of the Human Proteome
Novel method could alleviate bottleneck in bringing cancer biomarkers to the clinic and increase reproducibility of pre-clinical research.
Wednesday, December 18, 2013
Study Reveals Why Certain Ovarian Cancers Develop Resistance to Platinum-Based Chemotherapy
Researchers identified a mechanism that explains why some recurrent ovarian tumors become resistant to treatment with commonly used platinum-based chemotherapy drugs.
Wednesday, February 13, 2008
Scientific News
NIH Study Finds Calorie Restriction Lowers Some Risk Factors for Age-Related Diseases
Two-year trial did not produce expected metabolic changes, but influenced other life span markers.
Immunotherapy Agent Benefits Patients with Drug-Resistant Multiple Myeloma in First Human Trial
Daratumumab proved generally safe in patients, even at the highest doses.
Low-level Arsenic Exposure Before Birth Associated with Early Puberty in Female Mice
Study examine whether low-dose arsenic exposure could have similar health outcomes in humans.
Inciting an Immune Attack On Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
‘Mutation-Tracking’ Blood Test for Breast Cancer
Scientists have developed a blood test for breast cancer able to identify which patients will suffer a relapse after treatment, months before tumours are visible on hospital scans.
Cellular Contamination Pathway for Heavy Elements Identified
Berkeley Lab scientists find that an iron-binding protein can transport actinides into cells.
Intensity of Desert Storms May Affect Ocean Phytoplankton
MIT study finds phytoplankton are extremely sensitive to changing levels of desert dust.
Common ‘Heart Attack’ Blood Test May Predict Future Hypertension
Small rises in troponin levels may have value as markers for subclinical heart damage and high blood pressure.
LaVision BioTec Reports on the Neuro Research on the Human Brain After Trauma
Company reports on the work of Dr Ali Ertürk from the Institute for Stroke and Dementia Research at LMU Munich.
NIH Study Shows No Benefit of Omega-3 Supplements for Cognitive Decline
Research was published in the Journal of the American Medical Association.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
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
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!