Alzheimer's drug boosts perceptual learning in healthy adults

Sep 16, 2010

Research on a drug commonly prescribed to Alzheimer's disease patients is helping neuroscientists at the University of California, Berkeley, better understand perceptual learning in healthy adults.

In a new study, to be published online Thursday, Sept. 16, in the journal , researchers from UC Berkeley's Helen Wills Neuroscience Institute and School of Optometry found that study participants showed significantly greater benefits from practice on a task that involved discriminating directions of motion after they took donepezil, sold under the brand name Aricept, compared with a placebo.

Neither the researchers nor the participants knew whether they were taking the placebo or donepezil, a cholinesterase inhibitor that enhances the effects of the in the brain. Cholinesterase inhibitors act by blocking an enzyme that breaks down acetylcholine. Acetylcholine is known to play an important role in mediating and, in animal studies, has been found to promote changes in the brain that are associated with learning.

Donepezil, like other cholinesterase inhibitors, is used to treat early stages of and dementia. Previous research on donepezil has focused primarily on its beneficial effects on quality of life and clinical symptoms in patient populations. However, little was known about the specific that are enhanced by this drug.

"We wanted to better understand the biological mechanisms that underlie the ability to learn new tasks and to shed light on which specific neural processes are being enhanced by donepezil," said the study's principal investigator, Michael Silver, UC Berkeley assistant professor of optometry and neuroscience. "This is the first study to show that donepezil can enhance learning of a new skill, even in normal, healthy people."

The researchers tested 12 healthy, non-smoking adults ages 18-35. Subjects were tasked with detecting whether or not two fields of moving dots, presented one after the other, were moving in the same direction.

Each subject completed two 5-day courses of training on this task. In one of these courses of training, subjects ingested 5 milligrams of donepezil before every training session, and in the other, they took a placebo capsule before each training session. On average, the amount of improvement in performance of the task due to training increased two-fold when training occurred under the influence of donepezil.

However, the study authors noted that the improvements in the task being learned did not result in the same amount of improvement in performance on new motion direction discrimination tasks.

"The effects of donepezil were very specific to the task that the subjects were learning and practicing, and improvements elsewhere were much more moderate," said study lead author Ariel Rokem, a UC Berkeley post-doctoral fellow at the Helen Wills Neuroscience Institute. "As a comparison, with practice, a fruit inspector may become very good at judging small differences in color among red apples, but this learning may not completely transfer to the ability to discriminate shades of green apples."

It would be helpful to test the effectiveness of donepezil on other forms of learning, the study authors said. "We've established that donepezil enhances learning, so now we want to understand how this happens in the brain," said Silver. "We have a study underway where we use brain imaging to measure how the brain changes with learning and the impact of donepezil on these neural changes."

The researchers said that if enhancing the activity of acetylcholine in the brain is shown to benefit other forms of perceptual learning, it could eventually lead to clinical treatments for people with conditions other than Alzheimer's.

"Perceptual learning tasks are used to help patients with clinical conditions such as dyslexia and amblyopia," said Rokem. "Further research could find that cholinesterase inhibitors boost the effectiveness of treatments for these patients."

Explore further: Know the brain, and its axons, by the clothes they wear

Related Stories

Multi-sensory training: Faster learning

Aug 15, 2006

U.S. scientists from Boston University and UCLA say the use of multi-sensory training programs helps people improve low-level perceptual task learning.

Drugs may not delay onset of dementia; and more

Nov 27, 2007

Researchers have examined the evidence in favour of giving people considered to be close to developing dementia the drugs that are most commonly used to treat the condition itself. They have concluded that these drugs (cholinesterase ...

Recommended for you

Know the brain, and its axons, by the clothes they wear

Apr 18, 2014

(Medical Xpress)—It is widely know that the grey matter of the brain is grey because it is dense with cell bodies and capillaries. The white matter is almost entirely composed of lipid-based myelin, but ...

Turning off depression in the brain

Apr 17, 2014

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Rapid whole-brain imaging with single cell resolution

Apr 17, 2014

A major challenge of systems biology is understanding how phenomena at the cellular scale correlate with activity at the organism level. A concerted effort has been made especially in the brain, as scientists are aiming to ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

bottomlesssoul
not rated yet Sep 16, 2010
I've been using Donepezil analogs for years now. It really seems to work but I would be happier to know it wasn't purely placebo.

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.