X-Message-Number: 29691
From: "Basie" <>
Subject: DNA and memory
Date: Mon, 30 Jul 2007 13:53:38 -0400

London - Weddings and other big events are the stuff of memories. Now 
researchers have found a genetic change that makes some people remember them 
better than others.

The findings, published on Sunday in the journal Nature Neuroscience, could 
help in the treatment of a number of psychiatric conditions, including 
post-trauma disorders, the researchers said.

Scientists have long recognised a link between memory and strong emotional 
events and the important evolutionary role it plays in remembering dangerous 
or favourable situations, said Andreas Papassotiropoulos, a researcher who 
worked on the study.

But the mechanism that triggers or regulates these responses was unclear, 
Papassotiropoulos, a psychiatrist at the University of Basel, said.

"This is the first proof of principle that we are able to identify genes and 
variants for emotional memory in humans," he said.

Researchers around the world have been scouring the human genome to find 
genetic links to various diseases and conditions in the hope of developing 
new ways to prevent or treat them.

Papassotiropoulos, along with his colleague Dominique de Quervain at the 
University of Zurich, said a readily available database of human genes 
allowed them to zero in on a gene they believed was related to emotional 
memories.

In their study, the researchers collected DNA from 435 Swiss students and 
showed them a series of pictures such as a baby laughing, a car accident or 
a table. Then they asked them to remember what they had seen.

Most people remembered the emotional pictures better than the neutral ones, 
but there was a wide range in how well some people recalled the highly 
charged images, Papassotiropoulos, said.

"There was a huge spectrum of this memory performance," he said. "The result 
was people with the deleted gene remembered emotional pictures better than 
people without the deletion."

The team also wanted to see what would happen to people carrying this 
genetic change who had very strong negative emotional memories.

To do this, they interviewed a group of refugees from Rwanda's bloody civil 
war and found that survivors with the genetic change suffered more severe 
cases of post-traumatic stress syndrome, Papassotiropoulos said.

This showed that the same genetic mutation that helps people remember how to 
avoid a dangerous situation or recall a happy experience could also worsen 
bad memories, the researchers said.

"The deletion variant was not related to whether they had the disease or not 
but it was related to the amount of traumatic memories," he said.

The next step, Papassotiropoulos said, is to search through the whole human 
genome to find genes related to memory researchers did not know about 
before.

The findings also offer hope that one day scientists can develop drugs 
targeting a range of psychiatric conditions such as depression and anxiety 
where memory plays a key role, he said.

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