SIRT1 gene important for memory

Jul 22, 2010

A protein implicated in many biological processes also may play a role in memory, according to a study led by the University of Southern California and the National Institute on Aging at the National Institutes of Health.

The findings, published this week in the Journal of Neuroscience, agree with research by a different team published online by Nature on July 11. Both studies found that mice lacking the protein SIRT1 exhibited impaired memory and learning, suggesting SIRT1's importance to those functions.

However, the new study also found that boosting natural levels of SIRT1 protein did not improve learning or memory in the mice, raising questions about the case for supplementing a normal diet with sirtuin activators, a family of compounds targeted to activate SIRT1.

"The over-expression of SIRT1 did not improve memory, implying that increasing the amount of the protein may not enhance memory. Many more studies with different models are necessary, however, to rule this out," said co-corresponding author Valter Longo, a molecular biologist in the USC Leonard Davis School of with a joint appointment in the USC College of Letters, Arts and Sciences.

In mice, sirtuins have been shown to affect metabolism and other biological processes involved in aging. A number of studies have shown that resveratrol, a proposed sirtuin activator and much-advertised "anti-aging" ingredient in , has beneficial effects on some aspects of health, though it does not prolong life in normal mice. However, it does improve the health and extends the of mice on a high fat diet.

The physiological functions of sirtuins in humans are under intense investigation, with many ongoing studies on the effects of sirtuin activators and inhibitors on various diseases.

"This is a very controversial topic since sirtuins have been shown to be both good and bad," Longo noted. "In our previous studies [in mice and ], for example, we showed that it was the absence of SIRT1 that protected neurons.

"So maybe there is a trade-off between protection against toxicity and function such as that which is essential for learning and memory."

In the Longo group's study, mice missing the SIRT1 gene not only had cognitive problems, but also physical defects in their neural networks. The neurons of such mice had simpler structures with less branching and complexity - indicators of a decreased ability to learn and adapt.

At the other end, mice engineered to over-express the SIRT1 gene performed no better on learning and tests than normal . Their brains did not show any adverse physical characteristics.

Explore further: Why your nose can be a pathfinder

Related Stories

Gene linked to aging also linked to Alzheimer's

Jul 22, 2010

MIT biologists report that they have discovered the first link between the amyloid plaques that form in the brains of Alzheimer's patients and a gene previously implicated in the aging process, SIRT1.

Recommended for you

Researchers track down cause of eye mobility disorder

10 hours ago

Imagine you cannot move your eyes up, and you cannot lift your upper eyelid. You walk through life with your head tilted upward so that your eyes look straight when they are rolled down in the eye socket. ...

How kids' brain structures grow as memory develops

11 hours ago

Our ability to store memories improves during childhood, associated with structural changes in the hippocampus and its connections with prefrontal and parietal cortices. New research from UC Davis is exploring ...

User comments : 0

More news stories

Down's chromosome cause genome-wide disruption

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study published Wednesday that surprised its authors.

Simplicity is key to co-operative robots

A way of making hundreds—or even thousands—of tiny robots cluster to carry out tasks without using any memory or processing power has been developed by engineers at the University of Sheffield, UK.

Progress in the fight against quantum dissipation

(Phys.org) —Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. ...