Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Mental Health Center

Font Size

Gene May Explain Emotional Aspect of Fear

Genetic Differences May Shape Response to Fear

WebMD Health News

Sept. 28, 2005 -- A gene found deep in the emotional center of the brain may help explain why some people prefer to skydive while others are content with keeping both feet on the ground.

A new study shows that mice lacking one of a set of genes found in the emotional part of the brain called the amygdala react differently to fear and take more risks than their normal peers.

Researchers found the mice with only one copy of the gene, called neuro2, had an impaired emotional learning and showed abnormal responses to fear. Those without the set of genes did not have normal development and growth of this region of the brain.

"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," says researcher James Olson, MD, PhD, of the Fred Hutchinson Cancer Research Center, in a news release. "That's called emotional-memory formation. The amygdala is the part of the brain that is responsible for formation of emotional memory."

"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," says Olson.

Gene Linked to Fear Response

In the study, published in the Proceedings of the National Academy of Sciences, researchers looked at the effects of the neuroD2 gene in the brain development of mice.

First, they found that certain areas of the amygdala did not fully develop in mice bred without the gene. These mice also died within a few weeks after birth.

Second, they conducted a series of experiments to determine what effect having only one copy rather than the normal two copies of the gene had on the mice's emotional learning and development.

In one experiment, mice were exposed to a tone followed by a mild foot shock. Normal mice responded by crouching down and not moving the next time they heard the tone, which indicates they were expecting a shock. But the mice with only one copy of the gene did not freeze in anticipation of a shock.

Today on WebMD

Differences between feeling depressed or feeling blue.
lunar eclipse
Signs of mania and depression.
man screaming
Causes, symptoms, and therapies.
woman looking into fridge
When food controls you.
Woman standing in grass field barefoot, wind blowi
senior man eating a cake
woman reading medicine warnings
depressed young woman
man with arms on table
man cringing and covering ears

WebMD Special Sections