Proteins necessary for brain development found to be critical for long-term memory

Sep 05, 2006

A type of protein crucial for the growth of brain cells during development appears to be equally important for the formation of long-term memories, according to researchers at UC Irvine. The findings could lead to a better understanding of, and treatments for, cognitive decline associated with normal aging and diseases such as Alzheimer's.

The findings appear in the early online edition of the Proceedings of the National Academy of Sciences.

"This study presents strong evidence that a molecular process fundamental during development is retained in the adult and recycled in the service of memory formation," said Thomas J. Carew, Donald Bren Professor and chair of UCI's Department of Neurobiology and Behavior. "It is a striking example of how molecular rules employed in building a brain are often reused for different purposes throughout a lifetime."

The researchers have shown that proteins known as growth factors are as essential for the induction of long-term memory as they are for the development of the central nervous system. These growth factors, such as brain derived neurotrophic factor (BDNF), bind onto the brain cell through a specific type of receptor known as TrkB, much the same way a key fits into a lock. As an experimental strategy to determine the importance of BDNF-like growth factors in forming memories, the researchers used a "molecular trick" to keep the proteins from binding with the appropriate TrkB receptors.

For the experiment, the scientists used wild-caught Aplysia, a marine snail frequently studied in learning and memory because of its large brain cells. The Aplysia received a series of five tail shocks, spaced 15 minutes apart. The shocks cause the animals to exhibit heightened withdrawal reflexes days and weeks after the shocks are over.

When the animals are shocked, a brain chemical known as serotonin is released that promotes the formation of a long-term memory associated with the shocks. However, when Carew and his colleagues blocked the interaction between the BDNF-like growth factors and the TrkB receptors, they found that serotonin alone was not enough to retain the long-term memory of the shock. While short-term memory was retained, 24 hours later the snails -- which normally would remember the events of the previous day -- exhibited no memory of the shocks. Carew and colleagues went on to show that, when the actions of the growth factors were prevented, long-term enhancement of the connections between the brain cells in the reflex circuit normally induced by the shock treatment was also blocked.

"We would never have expected that the secretion of these growth factors in response to serotonin would be critical for long-term memory formation in this system," Carew said. "But it is apparent that without them, this process cannot happen."

According to Carew, these findings could open possible avenues for treatments relating to memory loss. "This gives us some strong clues as to what we should be looking into for therapeutic interventions," he said. "If we know that growth factors are important for long-term memory, then we can look at possible remedial roles they might play in diseases such as Alzheimer's and dementia."

Source: University of California, Irvine

Explore further: Canada pledges $440 million to vaccinate poor children

add to favorites email to friend print save as pdf

Related Stories

Beyond human: Exploring transhumanism

Nov 25, 2014

What do pacemakers, prosthetic limbs, Iron Man and flu vaccines all have in common? They are examples of an old idea that's been gaining in significance in the last several decades: transhumanism. The word ...

Looking for the best strategy? Ask a chimp

Jun 05, 2014

If you're trying to outwit the competition, it might be better to have been born a chimpanzee, according to a study by researchers at Caltech, which found that chimps at the Kyoto University Primate Research ...

Light field microscopy for whole brain activity maps

Jan 29, 2014

(Phys.org) —Advances in light-sheet microscopy have led to impressive images and videos of the brain in action. With this technique, a plane of light is scanned through the sample to excite fluorescent ...

Scientists engineer human stem cells

Dec 06, 2013

In an important scientific breakthrough in regenerative medicine, researchers at A*STAR's Genome Institute of Singapore have successfully converted human embryonic stem cells (hESCs) cultured in the laboratory to a state ...

Recommended for you

Syria hit by flesh-eating maggot disease

12 hours ago

Three cases of myiasis have been reported near Damascus, marking the first appearance of the flesh-eating maggot disease in Syria, UN health experts said Friday.

Brazil's Amazon region houses latex 'love factory'

13 hours ago

Deep in Amazonia, Raimundo Pereira expertly cuts a gash in a rubber tree to collect white sap destined for the nearby factory at Xapuri, the world's only producer of contraceptives made from tropical forest latex.

Ebola scare boosts business for US company

13 hours ago

The Ebola scare has subsided in the United States, at least temporarily, but an Alabama manufacturer is still trying to catch up with a glut of orders for gear to protect against the disease.

Sperm can carry Ebola for 82 days: WHO

13 hours ago

Sperm can carry the Ebola virus for at least 82 days, the World Health Organization said Friday, urging men recovering from the disease to use condoms for three months after the onset of symptoms.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.