We’ve all suffered through the last-minute exam cram—that largely futile attempt to memorize as much as possible in the final minutes before a test. No matter how hard we try to remember it all, the information often disappears the minute we read the first question. Whereas forming memories is an active and often exhausting process, losing them seems to happen quite passively as time elapses and new information overloads our busy brains.

But a new study published February 19 in the journal Cell shows that forgetting is a biochemically active process not unlike memory formation. The authors of the study, Yi Zhong and his colleagues from Tsinghua University in Beijing and Cold Spring Harbor Laboratory in Long Island, N.Y., drew their conclusions based on studies of fruit flies. They created Drosophila melanogaster in which they could turn off or turn up a protein called Rac, which plays several roles in intracellular signaling. Then they had the tiny flies perform three memory-forming tests. In the first, the flies learned to associate one of two odors with a negative consequence (a mild electric shock to a foot). In the second, the flies had to learn a new pair of odors and their consequences—a test called interference learning because it interferes with the memory of the first test. In the final test, called reversal learning, the consequences associated with the first pair of odors were reversed.

The researchers found that inhibiting the production of Rac slowed memory decay over time and suppressed forgetting: the flies performed better for longer on the first test but worse on the interference and reversal tests. Increased Rac activity had the opposite effect—it accelerated memory decay and promoted forgetting. The effects were independent of the formation of memories, because all flies acquired the memory of the first association equally.

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Elderly people with untreated poor vision are significantly more likely to suffer from Alzheimer’s disease and other forms of dementia than their clear-sighted counterparts, according to a study published online February 18 by the American Journal of Epidemiology. What’s more, the study suggests that vision problems may be a contributing factor in the development of dementia, rather than a symptom of it.

When elderly people with poor vision went to an ophthalmologist even once, their risk of dementia was reduced by 64 percent, the study found. People who had undergone eye procedures to treat glaucoma and correct cataracts were also less likely to develop dementia.

“Visual problems can have serious consequences and are very common among the elderly, but many of them are not seeking treatment,” said University of Michigan researcher Mary Rogers, the study’s lead author, in a prepared statement.

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A new study shows that drinking a daily dose of wild blueberry juice improved the memory of older adults with age-related memory problems. It’s the first study to show this potential benefit of blueberries in those at risk for dementia.
“The findings of this preliminary study suggest that moderate term blueberry supplementation can confer neurocognitive benefit,” write researcher Robert Krikorian, of the University of Cincinnati Academic Health Center, and colleagues in the Journal of Agricultural and Food Chemistry. Researchers say blueberries contain a wealth of phytochemicals that have antioxidant and anti-inflammatory effects.

(WebMD, 1/21/10)

The role of some brain structures are better understood than others. For example, the hippocampus, a small S-shaped structure that lies just inside your temples, plays a specific role in memory for facts, such as the capital of France (Paris), or events, such as what you had for breakfast (in my case, oatmeal).

Our knowledge of the hippocampus comes, in part, from a rare surgical procedure where an epileptic patient known as H.M. had a large portion of his hippocampus removed to prevent seizures. Although after the operation he suffered fewer seizures, he could no longer form new memories, such as remembering his doctors’ faces. Upon each visit, he introduced himself as if seeing them for the first time.

Imaging studies of patients with PTSD and depression reveal that part of their brain actually shrinks. They have a smaller hippocampus.

Given the fact that conditions such as PTSD are characterized by smaller hippocampi and a decline in memory, it might be important for treatments to address these deficits. Notably, patients with the worst memory performance have the most difficulty recovering.

The road to a high-functioning, herculean memory seems to be paved with a robust hippocampus, and PTSD and depression studies indicate that the hippocampus is dynamic and can change over time, for better or worse. It’s unclear whether SSRIs would improve memory for a healthy adult, but there is an alternative action which has shown promise as a memory enhancer. Exercise, well-documented as a stress-reliever and mood-booster, also helps improve the ability to remember words, facts and ideas. Why might this be? Following a 30-minute jog, a person has elevated levels of nerve-growth chemicals such as Brain-Derived Neurotrophic Factor (BDNF) which causes nerve cells in the hippocampus to multiply. The release of BDNF may boost both mood and memory, possibly explaining why exercise remains one of the best natural anti-depressants.

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Use it or lose it!

Pilot study by Alzheimers Australia (WA) finds regular brain exercises are the key to healthy ageing

Just two hours of brain exercises a week can markedly improve a person’s mental capacity and help fight age-related memory loss according to a recent study by Alzheimer’s Australia WA.

· Participants found improvements in their memory and were able to follow conversations better.
· Brain has the ability to change in response to new learning.
· Exercising the brain reduces the risk of developing dementia in later years.

The “Brain Fitness Pilot Project” involved people aged in their 60s, 70s and 80s from retirement villages and seniors fitness centres, taking part in a structured brain fitness program two hours per week over an eight-week period.

The program consisted of a series of computer-based hearing exercises aimed at sharpening a person’s ability to take in speech so that the brain can hear and remember more details.

While a majority of participants reported an improvement in their train of thought and could remember names and shopping lists better, another 70 percent found an improvement in their hearing and their ability to follow and remember conversations.

Alzheimer’s Australia WA Chief Executive Officer Frank Schaper said the study demonstrated that a regular program of brain exercises will reduce the impact of cognitive decline as a person grows older and can lead to healthy ageing.

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Persons with higher levels of leptin, a protein hormone produced by fat cells and involved in the regulation of appetite, may have an associated reduced incidence of Alzheimer disease and dementia, according to a study in the December 16 issue of JAMA.

Previous studies have shown that overweight and obesity in mid-life are associated with poorer cognitive function in the general population and an increased risk of dementia. There has been evidence that leptin exerts additional functions on the brain outside the hypothalamus (a region of the brain that controls body temperature, hunger, and thirst), according to background information in the article.

The researchers found that higher leptin levels were associated with a lower incidence of  dementia and AD. The incidence of dementia decreased gradually across increasing levels of leptin: a person with a baseline leptin level in the lowest quartile group had a 25 percent risk of developing AD after 12 years of follow-up, whereas the corresponding risk for a person in the top quartile group was only 6 percent.

“These findings are consistent with recent experimental data indicating that leptin improves memory function in animals through direct effects on the hippocampus and strengthens the evidence that leptin is a hormone with a broad set of actions in the central nervous system. Due to the exploratory character of the present analyses, we did not adjust for multiple comparisons and acknowledge that our findings require confirmation in independent samples,” the authors write.

“If our findings are confirmed by others, leptin levels in older adults may serve as one of several possible biomarkers for healthy brain aging and, more importantly, may open new pathways for possible preventive and therapeutic intervention. Further exploration of the molecular and cellular basis for the observed association may expand our understanding of the pathophysiology underlying brain aging and the development of AD.”
(JAMA 2009;302[23]:2565-2572. )

Seniors may be able to slow down memory loss by exercising the brain, experts say.

Doing crossword puzzles, playing cards and other games might ward off a decline in memory or help us maintain “brainpower” as we age, reports a study by the Rush Alzheimer’s Disease Center and Rush-Presbyterian-St. Luke’s Medical Center in Chicago. The study found that more frequent participation in cognitively stimulating activities is associated with a reduced risk of Alzheimer’s Disease.

The research looked at everyday activities such as reading books, newspapers or magazines, engaging in crossword puzzles or card games, and going to museums among aging participants. The 2002 study followed more than 700 dementia-free participants age 65 and older for an average of 4.5 years. The results indicated a one-point increase in cognitive activity corresponded with a 33 percent reduction in the risk of Alzheimer’s.

“The brain is like a muscle. If you don’t use it, you lose it,” said Jim Hanekamp, founder of Glenview-based Web site www.myfitbrain.com. The Web site features a variety of cognitive games that are geared to exercising the mind.

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