Chapter 7. Life-Span Development of the Brain and Behavior
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By Meeri Kim Babies start with simple vowel sounds — oohs and aahs. A mere months later, the cooing turns into babbling — “bababa” — showing off a newfound grasp of consonants. A new study has found that a key part of the brain involved in forming speech is firing away in babies as they listen to voices around them. This may represent a sort of mental rehearsal leading up to the true milestone that occurs after only a year of life: baby’s first words. Any parent knows how fast babies learn how to comprehend and use language. The skill develops so rapidly and seemingly without much effort, but how do they do it? Researchers at the University of Washington are a step closer to unraveling the mystery of how babies learn how to speak. They had a group of 7- and 11-month-old infants listen to a series of syllables while sitting in a brain scanner. Not only did the auditory areas of their brains light up as expected but so did a region crucial to forming higher-level speech, called Broca’s area. A year-old baby sits in a brain scanner, called magnetoencephalography -- a noninvasive approach to measuring brain activity. The baby listens to speech sounds like "da" and "ta" played over headphones while researchers record her brain responses. (Institute for Learning and Brain Sciences, University of Washington) These findings may suggest that even before babies utter their first words, they may be mentally exercising the pivotal parts of their brains in preparation. Study author and neuroscientist Patricia Kuhl says that her results reinforce the belief that talking and reading to babies from birth is beneficial for their language development, along with exaggerated speech and mouth movements (“Hiii cuuutie! How are youuuuu?”). © 1996-2014 The Washington Post
Tania Browne As a teenager, I lost my grandfather. But he wasn't dead. He still had his favourite music, he still loved to walk in the woods and name the flowers and plants, and he loved his soap operas. He was alive, but gone. A dignified man, a former aircraft engineer and oil company salesman, reduced to the status of a bewildered toddler lost in a shopping centre. When he died, our family felt an odd mix of relief, then guilt at the relief. The man we loved had left his body years before the body gave out. This was 30 years ago. But while a cure is still far away, two new techniques may at least be able to forewarn us of dementia, and allow us to plan treatment for ourselves or loved ones before any outward symptoms are apparent. According to Alzheimer's Research UK, my experience is currently shared by 24m relatives and close friends of the 800 000 diagnosed dementia sufferers in the UK. In December last year, a G8 summit was told by Alzheimer's Disease International that the worldwide figure was 44m and set to treble by 2050, as the life expectancy of people in middle and lower income countries soars – precisely the countries who have either depleted or non-existent healthcare systems. Dementia is a serious time bomb. “Dementia” covers about 100 conditions, all resulting from large scale brain cell death. People often think that when they're diagnosed they're in the early stages. Yet cell death can be occurring for 10-15 years or more before any outward symptoms occur, and by the time they're diagnosed many dementia patients have already lost one fifth of their memory cells. © 2014 Guardian News and Media Limited
Link ID: 19856 - Posted: 07.21.2014
|By Nidhi Subbaraman and SFARI.org A team at Duke University in Durham, North Carolina, is set to launch a $40 million clinical trial to explore stem cells from umbilical cord blood as a treatment for autism. But experts caution that the trial is premature. A $15 million grant from the Marcus Foundation, a philanthropic funding organization based in Atlanta, will bankroll the first two years of the five-year trial, which also plans to test stem cell therapy for stroke and cerebral palsy. The autism arm of the trial aims to enroll 390 children and adults. Joanne Kurtzberg, the trial’s lead investigator, has extensive experience studying the effectiveness of cord blood transplants for treating various disorders, such as leukemia and sickle cell anemia. Most recently, she showed that cord blood transplants can improve the odds of survival for babies deprived of oxygen at birth. A randomized trial of the approach for this condition is underway. “To really sort out if [stem] cells can treat these children, we need to do randomized, controlled trials that are well designed and well controlled, and that’s what we intend to do,” says Kurtzberg, professor of pediatrics and pathology at Duke. “We firmly believe we should be moving ahead in the clinic.” Early animal studies have shown that stem cells isolated from umbilical cord blood can stimulate cells in the spinal cord to regrow their myelin layers, and in doing so help restore connections with surrounding cells. Autism is thought to result from impaired connectivity in the brain. Because of this, some groups of children with the disorder may benefit from a stem cell transplant, Kurtzberg says. © 2014 Scientific American
Associated Press The rate of Alzheimer's disease and other dementias is falling in the United States and some other rich countries - good news about an epidemic that is still growing simply because more people are living to an old age, new studies show. An American over age 60 today has a 44 percent lower chance of developing dementia than a similar-aged person did roughly 30 years ago, the longest study of these trends in the U.S. concluded. Dementia rates also are down in Germany, a study there found. "For an individual, the actual risk of dementia seems to have declined," probably because of more education and control of health factors such as cholesterol and blood pressure, said Dr. Kenneth Langa. He is a University of Michigan expert on aging who discussed the studies Tuesday at the Alzheimer's Association International Conference in Copenhagen. The opposite is occurring in some poor countries that have lagged on education and health, where dementia seems to be rising. More than 5.4 million Americans and 35 million people worldwide have Alzheimer's, the most common form of dementia. It has no cure, and current drugs only temporarily ease symptoms. A drop in rates is a silver lining in the so-called silver tsunami - the expected wave of age-related health problems from an older population. Alzheimer's will remain a major public health issue, but countries where rates are dropping may be able to lower current projections for spending and needed services, experts said. © 2014 Hearst Communications, Inc.
Link ID: 19838 - Posted: 07.16.2014
By PAULA SPAN What we really want, if we’re honest, is a pill or a shot that would allow us to stop worrying about ever sinking into dementia. Instead, what we’re hearing about preventing dementia is, in many ways, the same stuff we hear about preventing other kinds of illnesses. Healthy lifestyles. Behavioral modification. Stress reduction. At the Alzheimer’s Association International Conference in Copenhagen this week, researchers from Montefiore Medical Center and the Albert Einstein College of Medicine were among the scientists presenting findings that had little to do with amyloid in the brain and a lot to do with how people feel and act and cope with life. “A number of people have been interested in modifiable lifestyle factors for years,” said Richard Lipton, a neurologist at the college and director of the Einstein Aging Study, which has tracked cognition in elderly Bronx residents since the 1980s. But interest has increased lately, he said: “It’s at least in part a reflection of disappointing drug trials.” Medications have failed, over and over, to prevent or cure or substantially slow the ravages of dementing diseases. What else might help? Dr. Lipton and his colleagues, who monitor about 600 people aged 70 to 105, have been exploring the impact of stress. More specifically, they have been measuring “perceived stress,” a metric not so much about unpleasant things happening as how people respond to them. They use a scale based on the answers to 13 questions like, “In the past month, how often have you felt confident about your ability to handle your personal problems?” and “In the past month, how often have you felt difficulties were piling up so high you could not overcome them?” © 2014 The New York Times Company
Link ID: 19837 - Posted: 07.16.2014
By Gary Stix Popular neuroscience books have made much in recent years of the possibility that the adult brain is capable of restoring lost function or even enhancing cognition through sustained mental or physical activities. One piece of evidence often cited is a 14-year-old study that that shows that London taxi drivers have enlarged hippocampi, brain areas that store a mental map of one’s surroundings. Taxi drivers, it is assumed, have better spatial memory because they must constantly distinguish the streets and landmarks of Shepherd’s Bush from those of Brixton. A mini-industry now peddles books with titles like The Brain that Changes Itself or Rewire Your Brain: Think Your Way to a Better Life. Along with self-help guides, the value of games intended to enhance what is known as neuroplasticity are still a topic of heated debate because no one knows for sure whether or not they improve intelligence, memory, reaction times or any other facet of cognition. Beyond the controversy, however, scientists have taken a number of steps in recent years to start to answer the basic biological questions that may ultimately lead to a deeper understanding of neuroplasticity. This type of research does not look at whether psychological tests used to assess cognitive deficits can be refashioned with cartoonlike graphics and marketed as games intended to improve mental skills. Rather, these studies attempt to provide a simple definition of how mutable the brain really is at all life stages, from infancy onward into adulthood. One ongoing question that preoccupies the basic scientists pursuing this line of research is how routine everyday activities—sleep, wakefulness, even any sort of movement—may affect the ability to perceive things in the surrounding environment. One of the leaders in these efforts is Michael Stryker, who researches neuroplasticity at the University of California San Francisco. Stryker headed a group that in 2010 published a study on what happened when mice run on top of a Styrofoam ball floating on air. They found that neurons in a brain region that processes visual signals—the visual cortex—nearly doubled their firing rate when the mice ran on the ball. © 2014 Scientific American
By ALEX STONE Last summer, in a failed attempt at humor, Clorox ran an online ad that declared, “Like dogs or other house pets, new dads are filled with good intentions but lacking the judgment and fine motor skills to execute well.” Although the company pulled the ad amid a flurry of scorn from the online commentariat, it nevertheless played to a remarkably widespread stereotype — that fathers are somehow unfit to raise children. In “Do Fathers Matter?” — spoiler alert: they do — the veteran science writer Paul Raeburn jumps to Dad’s defense, drawing on several decades of research and his own experience as a five-time father. What emerges is a thought-provoking field piece on the science of fatherhood, studded with insights on how to apply it in the real world. Historically, developmental psychologists have largely dismissed fathers as irrelevant. Nearly half the articles on child and adolescent psychology published in leading journals from 1997 to 2005, for example, make no mention of fathers; before 1970, when fathers weren’t even allowed in delivery rooms, less than a fifth of the research on parental bonding took them into account. This bias reflects a deeply ingrained assumption that fathers play a marginal role in how their children turn out, a belief enshrined in the theory of infant attachment, which grew out of the work of the British psychiatrist John Bowlby in the second half of the 20th century. “It focused exclusively on mothers,” Mr. Raeburn writes. “The role of the father, Bowlby believed, was to provide support for the mother. In the drama of childhood, he was merely a supporting actor.” This was more or less the established view until a few decades ago, when psychologists, motivated in part by the growing number of women entering the work force, finally started paying attention to fathers. © 2014 The New York Times Company
|By Maria Burke and ChemistryWorld The world needs to tackle head-on the market failures undermining dementia research and drug development, UK Prime Minister David Cameron told a summit of world health and finance leaders in London in June. He announced an investigation into how to get medicines to patients earlier, extend patents and facilitate research collaborations, to report this autumn. But just how much difference will these sorts of measures make when scientists are still grappling with exactly what causes different types of dementia? Added to these problems is that dementia has become a graveyard for a large number of promising drugs. A recent study looked at how 244 compounds in 413 clinical trials fared for Alzheimer's disease between 2002 and 2012. The researchers findings paint a gloomy picture. Of those 244 compounds, only one was approved. The researchers report that this gives Alzheimer's disease drug candidates one of the highest failures rates of any disease area – 99.6%, compared with 81% for cancer. ‘Dementia is a ticking bomb costing the global economy £350 billion and yet progress with research is achingly slow,’ warned the World Dementia Envoy, Dennis Gillings. Businesses need incentives to invest in research and bring in faster, cheaper clinical trials, or the world won’t meet the ambition to find a cure or disease-modifying therapy by 2025, he added. ‘We need to free up regulation so that we can test ground-breaking new drugs, and examine whether the period for market exclusivity could be extended.’ © 2014 Scientific American
Link ID: 19828 - Posted: 07.15.2014
By Fredrick Kunkle Sleep disturbances such as apnea may increase the risk of Alzheimer’s disease, while moderate exercise in middle age and mentally stimulating games, such as crossword puzzles, may prevent the onset of the dementia-causing disease, according to new research to be presented Monday. The findings — which are to be introduced during the six-day Alzheimer’s Association International Conference in Copenhagen — bolster previous studies that suggest sleep plays a critical role in the aging brain’s health, perhaps by allowing the body to cleanse itself of Alzheimer's-related compounds during down time. The studies also add to a growing body of literature that suggests keeping the brain busy keeps it healthy. The battle against Alzheimer’s disease has become more urgent for the United States and other developing nations as their populations turn increasingly gray. The disease is the leading cause of dementia in older people and afflicts more than 5 million Americans. At its current pace, the number is expected to soar to 16 million people by 2050. In 2012, the United States adopted a national plan to combat the disease and the G-8 nations last year adopted a goal of providing better treatment and prevention by 2025. Erin Heintz, a spokeswoman for the Alzheimer’s Association, said U.S. government funding to combat the disease now stands at about $500 million a year. To reach its 2025 goal, the United States should be spending $2 billion a year, she said.
One in three cases of Alzheimer's disease worldwide is preventable, according to research from the University of Cambridge. The main risk factors for the disease are a lack of exercise, smoking, depression and poor education, it says. Previous research from 2011 put the estimate at one in two cases, but this new study takes into account overlapping risk factors. Alzheimer's Research UK said age was still the biggest risk factor. Writing in The Lancet Neurology, the Cambridge team analysed population-based data to work out the main seven risk factors for Alzheimer's disease. These are: Diabetes Mid-life hypertension Mid-life obesity Physical inactivity Depression Smoking Low educational attainment They worked out that a third of Alzheimer's cases could be linked to lifestyle factors that could be modified, such as lack of exercise and smoking. The researchers then looked at how reducing these factors could affect the number of future Alzheimer's cases. They found that by reducing each risk factor by 10%, nearly nine million cases of the disease could be prevented by 2050. In the UK, a 10% reduction in risk factors would reduce cases by 8.8%, or 200,000, by 2050, they calculated. BBC © 2014
Link ID: 19824 - Posted: 07.14.2014
By Fredrick Kunkle A simple test of a person’s ability to identify odors and noninvasive eye exams might someday help doctors learn whether their patients are at risk of Alzheimer’s disease, according to research to be presented Sunday. With Alzheimer’s disease growing fast among the world’s aging population, researchers are increasingly focused on the search for new ways to detect and treat the brain-killing disease in its earliest stages. In two separate studies on the connection between dementia and sense of smell, teams of researchers found that a decreased ability to detect odors in older people, as determined by a common scratch-and-sniff test, could point to brain cell loss and the onset of dementia. In two other studies, researchers showed that noninvasive eye exams also might offer a way to identify Alzheimer’s in its early stages. The findings — which are to be presented at the Alzheimer’s Association International Conference in Copenhagen on Sunday — raise hopes that doctors could develop simple, inexpensive diagnostic tools that would hunt down reliable biomarkers of a disease that affects more than 5 million people in the United States. Alzheimer’s is a progressive and incurable disease that begins in areas of the brain associated with memory. It is the leading cause of dementia in older people, usually striking after the age of 65. It robs people of their cognitive abilities, speech and, ultimately, their identities. Eventually, it shuts down the most basic body functions, resulting in death.
Link ID: 19823 - Posted: 07.14.2014
by Helen Thomson You are what your grandmother ate, potentially, but maybe not what your great grandmother consumed. A study in mice shows that undernourishment during pregnancy increases the chances that the next two generations will develop obesity and diabetes. But by then the slate is wiped clean. If the same holds true for humans, it may mean that stressful events in our lives affect our grandchildren's health, but not great-grandchildren. Environmental stresses cause chemical changes to DNA that turn genes on and off. Many researchers believe that these changes can be passed down through sperm and eggs – a mechanism known as epigenetic inheritance. Low-calorie diet For example, studies have linked pregnant mothers that were undernourished during the second world war with gene changes in their children that put them at higher risk of becoming obese or getting cancer. But what happens to later generations is not clear. To model this effect, Anne Ferguson-Smith at the University of Cambridge and her colleagues fed pregnant mice a diet containing 50 per cent fewer calories than usual from the 12th day of gestation until the birth, which is normally after about 20 days. Offspring were smaller than average and developed diabetes when fed a healthy diet. When the male pups had offspring, they were also at higher risk of becoming diabetic. The team analysed the sperm of the offspring from the undernourished mothers to see how many genes had had their expression altered by the addition or removal of a methyl group – an epigenetic change. The team found a decrease in methylation in 111 regions of the DNA compared with sperm from mice born to mothers fed a healthy diet. © Copyright Reed Business Information Ltd
Erika Check Hayden Nearly 750,000 babies born each year in the United Kingdom are at risk of brain damage because of low oxygen during birth. Cooling babies who are at risk of brain damage provides long-lasting prevention of such injuries, researchers report today in the New England Journal of Medicine1. A team led by Denis Azzopardi, a neonatologist at King’s College London, lowered the body temperature of 145 full-term babies who were born after at least 36 weeks of gestation. All were at risk of brain damage because they had been deprived of oxygen during birth — a problem that is often caused by troubles with the placenta or umbilical cord, and affects nearly 750,000 babies a year in the United Kingdom. The researchers cooled the infants to between 33°C and 34°C for 72 hours, starting within 6 hours of birth. The technique is known to boost the chances that children avoid brain damage until they become toddlers2, but any longer-term benefits have remained unclear. The study finds treated babies had better mental and physical health than untreated infants through to ages 6 or 7: they were 60% more likely to have normal intelligence, hearing and vision. Those who survived to childhood also had fewer disabilities such as difficulty walking and seeing. "The bottom line is that this doubles a child’s chance of normal survival," says David Edwards, a neonatologist at King’s College London and an author of the study. Neonatologist David Rowitch from the University of California, San Francisco, who studies treatments for paediatric brain damage, says the new findings are important because they show sustained improvements. "This study is encouraging, adding to the weight of evidence showing both positive early indicators and also school-age benefits to hypothermia," Rowitch adds. © 2014 Nature Publishing Group,
Keyword: Development of the Brain
Link ID: 19814 - Posted: 07.10.2014
Thomas B. Edsall It’s been a key question of American politics since at least 1968: Why do so many poor, working-class and lower-middle-class whites — many of them dependent for survival on government programs — vote for Republicans? The debate over the motives of conservative low-income white voters remains unresolved, but two recent research papers suggest that the hurdles facing Democrats in carrying this segment of the electorate may prove difficult to overcome. In “Obedience to Traditional Authority: A heritable factor underlying authoritarianism, conservatism and religiousness,” published by the journal Personality and Individual Differences in 2013, three psychologists write that “authoritarianism, religiousness and conservatism,” which they call the “traditional moral values triad,” are “substantially influenced by genetic factors.” According to the authors — Steven Ludeke of Colgate, Thomas J. Bouchard of the University of Minnesota, and Wendy Johnson of the University of Edinburgh — all three traits are reflections of “a single, underlying tendency,” previously described in one word by Bouchard in a 2006 paper as “traditionalism.” Traditionalists in this sense are defined as “having strict moral standards and child-rearing practices, valuing conventional propriety and reputation, opposing rebelliousness and selfish disregard of others, and valuing religious institutions and practices.” Working along a parallel path, Amanda Friesen, a political scientist at Indiana University, and Aleksander Ksiazkiewicz, a graduate student in political science at Rice University, concluded from their study comparing identical and fraternal twins that “the correlation between religious importance and conservatism” is “driven primarily, but usually not exclusively, by genetic factors.” The substantial “genetic component in these relationships suggests that there may be a common underlying predisposition that leads individuals to adopt conservative bedrock social principles and political ideologies while simultaneously feeling the need for religious experiences.” © 2014 The New York Times Company
By Helen Briggs Health editor, BBC News website The same genes drive maths and reading ability, research suggests. Around half of the genes that influence a child's aptitude for reading also play a role in how easily they learn maths, say scientists. The study of 12-year-old British twins from 3,000 families, reported in Nature Communications, adds to the debate about the role of genes in education. An education expert said the work had little relevance for public policy as specific genes had not been identified. Past research suggests both nature and nurture have a similar impact on how children perform in exams. One study found genes explained almost 60% of the variation in GCSE exam results. However, little is known about which genes are involved and how they interact. The new research suggests a substantial overlap between the genetic variations that influence mathematics and reading, say scientists from UCL, the University of Oxford and King's College London. But non-genetic factors - such as parents, schools and teachers - are also important, said Prof Robert Plomin of King's College London, who worked on the study. "The study does not point to specific genes linked to literacy or numeracy, but rather suggests that genetic influence on complex traits, like learning abilities, and common disorders, like learning disabilities, is caused by many genes of very small-effect size," he said. BBC © 2014
by Helen Thomson A blood test for Alzheimer's might be just two years away. Abdul Hye at King's College London and his colleagues have identified 10 proteins in blood that can predict who will develop Alzheimer's disease a year after having mild memory problems. Its accuracy is almost 90 per cent. That could prove a huge boost for researchers seeking treatments. So far, trials of Alzheimer's drugs are thought to have failed because they have been given too late in the course of the disease to halt progression. The new blood test will initially be used to identify those people with mild cognitive impairment who are likely to get Alzheimer's disease and so might be good candidates for clinical trials to find drugs that halt disease progression. "Having a blood test is a really big step forward," says team member Ian Pike of Proteome Sciences in Cobham, UK. "The most important thing we can do is get the correct patients into clinical trials so we can tell, for example, whether it is a drug that is slowing the progression of the disease or the fact that we just happen to have a group of patients who have a slow progressing form of the disease." "This [blood test] is a technical tour de force," says Eric Karran, director of research at the Alzheimer's Research UK charity. However, he remains cautious about its use beyond clinical research. For every 10 people who take the test, one will get an incorrect result. "Alzheimer's is the most feared diagnosis, so we have to be careful, particularly in the absence of any treatment," he says. © Copyright Reed Business Information Ltd.
Link ID: 19802 - Posted: 07.08.2014
|By Jessica Wright and SFARI.org CHD8, a gene that regulates the structure of DNA, is the closest thing so far to an ‘autism gene,’ suggests a study published today in Cell. People with mutations in this gene all have the same cluster of symptoms, including a large head, constipation and characteristic facial features; nearly all also have have autism. Autism is notoriously heterogeneous, perhaps involving mutations in any of hundreds of genes. Typically, researchers begin by studying people with similar symptoms and working backward to identify what causes those symptoms. But that approach has not been particularly productive. “We’ve tried for so long to identify subtypes of autism based on behavior alone and we’ve done abysmally at that,” says lead researcher Raphael Bernier, associate professor of psychiatry at the University of Washington in Seattle. The reverse approach — that is, beginning with people who all have mutations in the same gene and characterizing their symptoms — may prove to be more useful for simplifying autism’s complexity. For example, identifying subtypes of autism may help researchers develop drugs tailored to that particular cause, says Evan Eichler, professor of genome sciences at the University of Washington, who spearheaded the genetics side of the study. “I think the most important realization is that not all autisms are created equal,” he says. © 2014 Scientific American,
By Helen Briggs Health editor, BBC News website More than 99% of drug trials for Alzheimer's disease during the past decade have failed, according to a study. There is an urgent need to increase the number of potential therapies being investigated, say US scientists. Only one new medicine has been approved since 2004, they report in the journal Alzheimer's Research & Therapy. The drug failure rate is troubling and higher than for other diseases such as cancer, says Alzheimer's Research UK. Dr Jeffrey Cummings, of the Cleveland Clinic Lou Ruvo Center for Brain Health, in Las Vegas, and colleagues, examined a public website that records clinical trials. Between 2002 and 2012, they found 99.6% of trials of drugs aimed at preventing, curing or improving the symptoms of Alzheimer's had failed or been discontinued. This compares with a failure rate of 81% for cancer drugs. The failure rate was "especially troubling" given the rising numbers of people with dementia, said Dr Simon Ridley, of Alzheimer's Research UK. "The authors of the study highlight a worrying decline in the number of clinical trials for Alzheimer's treatments in more recent years," he said. "There is a danger that the high failure rates of trials in the past will discourage pharmaceutical companies from investing in dementia research. BBC © 2014
Link ID: 19793 - Posted: 07.04.2014
By Smitha Mundasad Health reporter, BBC News Researchers have identified a gene that may put people at greater risk of strokes and heart attacks. Writing in PLOS ONE they say the gene fault may encourage the formation of blood clots - the ultimate cause of most heart attacks and strokes. Scientists hope gene tests may help doctors one day to pinpoint individuals more likely to suffer these conditions. But experts say lifestyle factors such as smoking and exercise have the greatest influence on risk. Around one in 10 people in the Caucasian population carries this variation of the gene, named PIA2. And researchers from King's College London reviewed more than 80 studies involving about 50,000 people - the largest analysis of this genetic fault to date. Threat to under-45s They found individuals with PIA2 were more likely to have a stroke - caused by a blood clot blocking blood supply to the brain - than those without the gene. Scientists calculate the gene increases a person's risk of having a stroke by 10-15%. But how significant this increase is depends on an individual's baseline risk - influenced by factors such as smoking, diet, weight and exercise, the scientists say. Heart attacks are caused by a blockage to the blood vessels that carry oxygen to the heart. More than 100,000 heart attacks are recorded in the UK each year And for people with two copies of the gene the risk rises by up to 70% from this baseline. In a second study published in the same journal, the scientists show PIA2 is also linked to an increased risk of heart attacks in people under 45. More research is needed to see whether this holds true for the whole population, they say. About 150,000 people have a stroke in the UK each year and more than 100,000 heart attacks are recorded annually. BBC © 2014
By GRETCHEN REYNOLDS Exercise may help to keep the brain robust in people who have an increased risk of developing Alzheimer’s disease, according to an inspiring new study. The findings suggests that even moderate amounts of physical activity may help to slow the progression of one of the most dreaded diseases of aging. For the new study, which was published in May in Frontiers in Aging Neuroscience, researchers at the Cleveland Clinic in Ohio recruited almost 100 older men and women, aged 65 to 89, many of whom had a family history of Alzheimer’s disease. Alzheimer’s disease, characterized by a gradual and then quickening loss of memory and cognitive functioning, can strike anyone. But scientists have discovered in recent years that people who harbor a specific variant of a gene, known as the APOE epsilon4 allele or the e4 gene for short, have a substantially increased risk of developing the disease. Genetic testing among the volunteers in the new study determined that about half of the group carried the e4 gene, although, at the start of the study, none showed signs of memory loss beyond what would be normal for their age. Then the scientists set out to more closely examine their volunteers’ brains. For some time, researchers have suspected that Alzheimer’s disease begins altering the structure and function of the brain years or even decades before the first symptoms appear. In particular, it’s been thought that the disease silently accelerates the atrophy of the hippocampus, a portion of the brain critical for memory processing. Brain scans of people who have Alzheimer’s show that their hippocampi are considerably more shrunken than those of people of the same age without the disease. There’s been less study, though, of possible shrinkage in the brains of cognitively normal people at risk for Alzheimer’s. One reason is that, until recently, few interventions, including drugs, had shown much promise in slowing or preventing the disease’s progression, so researchers – and patients – have been reluctant to identify markers of its potential onset. © 2014 The New York Times Company
Link ID: 19783 - Posted: 07.02.2014