Norepinephrine

There is this interesting article i read. It is about the brain chemical that makes bad memories stay. Here is the copy of the article.

We bank on our memory to help us recall things in our daily lives. We welcome good memories, but bad memories are just sometimes here to stay no matter how much we want to forget them. A group of scientists may hold the answer to this mystery.

Researchers theorized that stress hormone called Norepinephrine aids in the release of a chemical receptor in the brain called GluR1. This helps the brain to make memories easier, allowing the brain to remember what happened to avoid a certain stressful event from recurring.

Hailan Hu, PhD and Roberto Manilow, MD,PhD, from the Cold Spring Harbor Laboratory in New York, tested this theory in mice. They injected a group of mice with epinephrine (which boosts norephinephrine), and another group with salt water (which does not affect norepinephrine).

On the first day of the test, the mice were put in a cafe and were allowed to explore for awhile. The next day, the mice got a mild electrical shock as soon as they were placed in the same cage. Scientists then videotaped the mice on the last day of the experiment to see which group of mice stood still longer after being put back in the cage. The epinephrine group was shown to have stood still longer compared to the salt water group. The scientists took that as a sign of "fear-based learning".

Additional tests found that GluR1 played a crucial role in that experiment. Although scientists believe that other chemical chain reactions in the brain may have also been involved. STudy results were purblished in the journal Cell.


Source: Health & Lifestyle, adding life to living. (nov-dec. 2007, p8)