by Carl Zimmer Fear: See also dread, panic, terror, fright, trepidation, anxiety, worry, phobia, disquietude, angst, foreboding, the creeps, the jitters, the heebie-jeebies, freaking out. Any halfway decent thesaurus will provide a long list of synonyms for fear, and yet they are not very good substitutes. No one would confuse having the creeps with being terrified. It is strange that we have so many words for fear, when fear is such a unitary, primal feeling. Perhaps all those synonyms are just linguistic inventions. Perhaps, if we looked inside our brains, we would just find plain old fear. That is certainly how things seemed in the early 1900s, when scientists began studying how we come to be scared of things. They built on Ivan Pavlov’s classic experiments on dogs, in which Pavlov would ring a bell before giving his dogs food. Eventually they learned to associate the bell with food and began to salivate in anticipation. Psychologists set up experiments to see if the same kind of learning could instill fear as well. The implicit assumption was that fear, like hunger, was a simple provoked response. In one of the most famous (and infamous) of these experiments, American psychologist John Watson decided to see if he could teach an 11-month-old baby named Albert to become scared of arbitrary things. He presented Albert with a rat, and every time the baby reached out to touch it, Watson hit a steel bar with a hammer, producing a horrendous clang. After several rounds with the rat and the bar, Watson then brought out the rat on its own. “The instant the rat was shown, the baby began to cry,” Watson wrote in a 1920 report.

Keyword: Emotions; Learning & Memory
Link ID: 13786 - Posted: 06.24.2010

by Greg Miller SAN DIEGO—The hormone progesterone is best known for its work in the female reproductive system, where it plays various roles in supporting pregnancy. But starting next month, it will be the focus of a phase III clinical trial for traumatic brain injury (TBI). Researchers hope an infusion of progesterone given within a few hours of a car accident or other trauma will help prevent brain damage, said the trial’s principal investigator, David Wright of Emory University in Atlanta. He described the upcoming trial here today at the annual meeting of the American Association for the Advancement of Science (which publishes ScienceNOW). The rationale for the trial springs from a chance finding made more than a quarter of century ago. While studying the effects of head injuries in rats, Emory researcher Donald Stein noticed that females had fewer ill effects than did males. Females who were at the progesterone peak of their menstrual cycle did even better. Follow-up studies with other animals also pointed to neuroprotective effects of progesterone, which is present in both the male and the female brain. In recent years, two small clinical trials suggested that progesterone can reduce mortality and disability after TBI in people. The new trial will provide a sterner test. It aims to enroll 1140 patients at 17 centers across the United States. Each patient will receive an infusion of progesterone starting within 4 hours of his or her injury and lasting 4 days. © 2010 American Association for the Advancement of Science.

Keyword: Stroke; Hormones & Behavior
Link ID: 13785 - Posted: 06.24.2010

By Sharon Begley | NEWSWEEK By now, it should come as no surprise when scientists discover yet another case of experience changing the brain. From the sensory information we absorb to the movements we make, our lives leave footprints on the bumps and fissures of our cortex, so much so that experiences can alter "hard-wired" brain structures. Through rehab, stroke patients can coax a region of the motor cortex on the opposite side of the damaged region to pinch-hit, restoring lost mobility; volunteers who are blindfolded for just five days can reprogram their visual cortex to process sound and touch. Still, scientists have been surprised at how deeply culture—the language we speak, the values we absorb—shapes the brain, and are rethinking findings derived from studies of Westerners. To take one recent example, a region behind the forehead called the medial prefrontal cortex supposedly represents the self: it is active when we ("we" being the Americans in the study) think of our own identity and traits. But with Chinese volunteers, the results were strikingly different. The "me" circuit hummed not only when they thought whether a particular adjective described themselves, but also when they considered whether it described their mother. The Westerners showed no such overlap between self and mom. Depending whether one lives in a culture that views the self as autonomous and unique or as connected to and part of a larger whole, this neural circuit takes on quite different functions. "Cultural neuroscience," as this new field is called, is about discovering such differences. Some of the findings, as with the "me/mom" circuit, buttress longstanding notions of cultural differences. For instance, it is a cultural cliché that Westerners focus on individual objects while East Asians pay attention to context and background (another manifestation of the individualism-collectivism split). Sure enough, when shown complex, busy scenes, Asian-Americans and non-Asian--Americans recruited different brain regions. The Asians showed more activity in areas that process figure-ground relations—holistic context—while the Americans showed more activity in regions that recognize objects. © 2010 Newsweek, Inc.

Keyword: Learning & Memory; Evolution
Link ID: 13784 - Posted: 06.24.2010

Being happy and staying positive may help ward off heart disease, a study suggests. US researchers monitored the health of 1,700 people over 10 years, finding the most anxious and depressed were at the highest risk of the disease. They could not categorically prove happiness was protective, but said people should try to enjoy themselves. But experts suggested the findings may be of limited use as an individual's approach to life was often ingrained. At the start of the study, which was published in the European Heart Journal, participants were assessed for emotions ranging from hostility and anxiousness to joy, enthusiasm and contentment. They were given a rating on a five-point scale to score their level of positive emotions. By the end of the analysis, some 145 had developed heart disease - fewer than one in 10. But for each rise in the happiness scale there was a 22% lower risk of developing heart disease. The team believes happier people may have better sleeping patterns, be less liable to suffer stress and be more able to move on from upsetting experiences - all of which can put physical strain on the body. Lead researcher Dr Karina Davidson admitted more research was needed into the link, but said she would still recommend that people try to develop a more positive outlook. She said all too often people just waited for their "two weeks of vacation to have fun" when instead they should seek enjoyment each day. If you enjoy reading novels, but never get around to it, commit to getting 15 minutes or so of reading in. If walking or listening to music improves you mood, get those activities in your schedule. Essentially spending a few minutes each day truly relaxed and enjoying yourself is certainly good for your mental health and may improve your physical health as well." (C)BBC

Keyword: Emotions
Link ID: 13783 - Posted: 02.18.2010

Amber Dance Scientists in the United States must publicly discuss the merits of animal research if they are to win over the public and neutralize the threat from activists. That was the view of animal-research supporters at a landmark panel discussion yesterday, which saw them come face to face with anti-vivisectionists at the University of California, Los Angeles (UCLA). In recent years, University of California scientists have faced threats of violence from animal-rights activists, with firebomb incidents at the Los Angeles and Santa Cruz campuses. But Colin Blakemore, a neuroscientist at the University of Oxford, UK, and a vocal supporter of animal research who has faced numerous attacks from activists, said that scientists in the United Kingdom have made progress in dealing with the problem by engaging with the media and the public. "The only way to breakthroughs is to have the courage to be open," Blakemore told Nature. But examples of such dialogue have been few and far between in the United States. "Scientists for a long time have not fulfilled society's expectations of being fully engaged about what they're doing," said J. David Jentsch, a UCLA neuroscientist and founder of the UCLA Pro-Test for Science animal-research advocacy group, before the event. "We really felt the time was ripe." © 2010 Nature Publishing Group

Keyword: Animal Rights
Link ID: 13782 - Posted: 06.24.2010

by Rajendrani Mukhopadhyay Is that Folgers coffee in your cup or Maxwell House? Now you no longer have to rely on your nose to tell. Researchers have developed an analyzer that can distinguish between 10 commercial brands of coffee and can even tell apart coffee beans roasted at various temperatures for different times. The advance could help growers determine within minutes whether a particular batch of coffee is just as good as the previous one or whether it's undrinkable. Researchers have been trying for years to come up with a simple way to analyze coffee. But it's no easy task. The challenge is that the aroma of roasted coffee beans consists of more than 1000 compounds that change with roasting temperatures and time. Traditional methods of chemical analysis like gas chromatography combined with mass spectrometry generally have difficulty distinguishing between compounds that are very similar to one another. And "electronic noses," an array of dyes, and other sensors that change color or chemical properties when they react with certain molecules suffer from the same drawback. Over the past decade, chemist Kenneth Suslick and colleagues at the University of Illinois, Urbana-Champaign, have refined the electronic nose approach. In the new study, they used dyes that interact strongly with other chemicals, making them more specific. They then put drops of 36 dyes on a polymer film the size of a nickel. The pigments in the dyes belonged to a range of chemical classes, including metalloporphyrins (a class of molecules which give blood and chlorophyll their distinctive colors); pH indicators; and molecules that change color with certain chemical vapors. © 2010 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste); Robotics
Link ID: 13781 - Posted: 06.24.2010

Liz Else, associate editor Challenging a multibillion-dollar global industry is bound to be an uncomfortable mission, all the more so if you risk being accused of promoting suffering, being a denialist, or even of culpable ignorance. Few writers who take on the mental health industry can be doing it for the money or in the hopes of sales matching Peter Kramer's 1990s hit Listening to Prozac. It was Kramer who coined the phrase "cosmetic psychopharmacology" to describe a not-too-distant utopia in which drugs such as the selective serotonin reuptake inhibitor Prozac, normally used to treat depression, would be used to enhance or change personality. Kramer did warn of the drug's downsides (tremors, loss of libido, suicidal ideation), but the prospect of exchanging shyness, timidity and other social dysfunctions for self-assurance, gregariousness and success ensured the book's popularity. Fast-forward to 2010 and optimism about biochemical aids in the endless pursuit of happiness or as fixes for misery seems to be vanishing like the morning mist. Writers continue to take the mental health industry apart, big genetics still fails to nail "genes for" mental illness in any important sense, and the deadline for a new edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders has slipped a year amid ugly rows and claims that tens of millions of dollars could be spent on unnecessary drugs should new diseases with no clear scientific foundation be included in the DSM. © Copyright Reed Business Information Ltd.

Keyword: Depression
Link ID: 13780 - Posted: 06.24.2010

By Cristen Conger Chronic insomniacs losing out on sleep may also be missing brain matter. For the first time, brain imaging has linked chronic insomnia to lower gray matter density in areas that regulate the brain's ability to make decisions and to rest. The research could lead to new treatment plans for people who struggle with sleeplessness. "The findings predict that chronic insomnia sufferers may have compromised capacities to evaluate the affective value of stimuli," said Ellemarijie Altena, lead author of the study from the Netherlands Institute for Neuroscience. "This could have consequences for other cognitive processes, notably decision-making." The study, published in Biological Psychiatry, compared the white and gray matter volumes of 24 older, chronic insomnia patients to 13 normal sleepers, and controlled for physical and psychiatric disorders that could also alter brain densities. Severe insomniacs exhibited the most extensive density loss, regardless of how long they had suffered from the disorder. However, the researchers are not yet able to pin down whether sleeplessness precedes gray matter loss or the other way around. © 2010 Discovery Communications, LLC

Keyword: Sleep; Brain imaging
Link ID: 13779 - Posted: 06.24.2010

by Ewen Callaway A GENE variant that ups your risk of developing Alzheimer's disease in old age may not be all bad. It seems that young people with the variant tend to be smarter, more educated and have better memories than their peers. The discovery may improve the variant's negative image (see "Yes or no"). It also suggests why the variant is common despite its debilitating effects in old age. Carriers of the variant may have an advantage earlier in life, allowing them to reproduce and pass on the variant before its negative effects kick in. "From an evolutionary perspective it makes sense," says Duke Han at Rush University Medical Center in Chicago. The "allele" in question is epsilon 4, a version of the apolipoprotein E gene (APOE). Having one copy increases the risk of developing Alzheimer's at least fourfold compared with people who have other forms of the gene. A person with two copies has up to 20 times the risk. One big clue that epsilon 4 might be beneficial emerged several years ago, when Han's team scanned the APOE genes of 78 American soldiers. All had suffered traumatic brain injuries, many while serving in Iraq. Sixteen had at least one copy of epsilon 4. Han's team expected to find that these carriers would be in worse cognitive shape than their counterparts with different versions of APOE, given previous studies that showed elderly people with epsilon 4 fare worse after head injury. But the opposite was true: soldiers with the epsilon 4 allele had better memory and attention spans (Journal of Neurology, Neurosurgery & Psychiatry, DOI: 10.1136/jnnp.2006.108183). © Copyright Reed Business Information Ltd

Keyword: Alzheimers; Learning & Memory
Link ID: 13778 - Posted: 06.24.2010

Andy Coghlan, reporter Remember Rom Houben, the man thought to be in a vegetative state, who turned out to have been fully conscious and "locked in" for more than 20 years? It has now emerged that doubts that he was really communicating using residual movement in his finger and a touchscreen were spot on. "Powerlessness. Utter powerlessness. At first I was angry, then I learned to live with it." That's what Houben, brain damaged in a car accident in 1983, apparently told the world by communicating via a computer touch-screen, at least according to the original report of Houben's story in Der Spiegel in November 2009. The story attracted huge media attention, which quickly turned sour when several videos of Houben typing at the screen prompted commentators to cry foul. They pointed out that the speed of the typing, and the fact that Houben is not even looking at the keyboard at various points in the footage, suggested it was in fact the person holding his finger who was behind the messages. Now, according to a follow-up article in Der Spiegel, it seems these suspicions have been borne out. The magazine reports that Steven Laureys of the University of Liège in Belgium, who first diagnosed Houben as conscious, but dissociated himself from the communication fiasco, has carried out subsequent tests to see if Houben is capable of this kind of communication. He concludes that the speech therapist holding Houben's finger was in fact the source of the messages. © Copyright Reed Business Information Ltd.

Keyword: Attention
Link ID: 13777 - Posted: 06.24.2010

WASHINGTON - A hormone thought to encourage bonding between mothers and their babies may foster social behavior in some adults with autism, French researchers said on Monday. They found patients who inhaled the hormone oxytocin paid more attention to expressions when looking at pictures of faces and were more likely to understand social cues in a game simulation, the researchers said in the journal Proceedings of the National Academy of Sciences. Angela Sirigu of the Center of Cognitive Neuroscience in Lyon, who led the study, said the hormone has a therapeutic potential in adults as well as in children with autism. "For instance, if oxytocin is administered early when the diagnosis is made, we can perhaps change very early the impaired social development of autistic patients," Sirigu said in an email. Sirigu said the study focused on oxytocin because it was known to help breast-feeding mothers bond with their infants and because earlier research has shown that some children with autism have low levels of the hormone. People with Asperger's syndrome and other autism spectrum disorders often have problems with social interaction. Sirigu said oxytocin could help autism patients who have normal intellectual functions and fairly good language abilities because it improves eye contact. Copyright 2010 Reuters

Keyword: Autism; Hormones & Behavior
Link ID: 13776 - Posted: 06.24.2010

By Sandra G. Boodman Karen Hammerman could see that her son was upset, and when he told her why, she was unnerved. Adam Hammerman, then a 16-year-old sophomore at Charles E. Smith Jewish Day School in Montgomery County, had missed a week of school because of a virus and telephoned several classmates to see what assignments he'd missed. "Something's wrong," he told his mother last May. "All my friends are mad at me. They say I've called them five times already and they're not going to tell me again." But Adam had no memory of making the calls. The incident, Karen Hammerman soon discovered, was not isolated. One morning as Adam prepared to take a shower, he screamed after seeing himself in the mirror: He said he did not remember getting a haircut the previous day. He called his mother from school to ask what time she was picking him up, then called again five minutes later to ask the same thing. "Basically it was like living with a 16-year-old Alzheimer's patient," Karen Hammerman recalled. Despite numerous tests, nearly a dozen doctors in Washington and Baltimore could find no reason for Adam's sudden and profound memory loss. "They would either tell me, 'I've never seen anything like this,' or else that he's making it up," his mother recalled. One neurologist's assistant castigated Hammerman for insisting on expensive tests for a problem that was clearly psychological. © 2010 The Washington Post Company

Keyword: Learning & Memory
Link ID: 13775 - Posted: 06.24.2010

By LAURA BEIL HOUSTON — One callous question turned Brittany Caesar into a medical pioneer: “Why do you eat so much? It’s not normal.” At that moment, she was in the Campbell Middle School cafeteria, sitting down to her usual lunch: two cheeseburgers, two orders of fries and a Coke. She knew she weighed too much. Her whole family weighed too much. But her world revolved around food, and she could not imagine any other existence. “Food was my best friend,” she said. “It was always there for me.” Somehow, her classmate’s taunt, back in 2003, wounded her in a way the usual fat jokes never had. She fled to the bathroom and wept, vowing to lose weight. Her salvation did not arrive until more than a year later when, at age 14, doctors at Texas Children’s Hospital performed a gastric bypass that left her stomach the size of an egg. On the day of surgery, she weighed 404 pounds. Ms. Caesar, now 20 years old and 175 pounds, was the first teenager to undergo a gastric bypass at Texas Children’s, but more quickly followed. Today, it maintains one of the busiest bariatric practices for adolescents in the country, performing one or two bypasses each month. Although the procedure is still considered experimental for children, it is fast becoming the next front in the battle against pediatric obesity. “I honestly believe that in 5 to 10 years you’ll see as many children getting weight-loss procedures as adults,” said Dr. Evan Nadler, co-director of the Obesity Institute at Children’s National Medical Center in Washington. Copyright 2010 The New York Times Company

Keyword: Obesity; Development of the Brain
Link ID: 13774 - Posted: 06.24.2010

A gene that may give you an increased risk of a distressing early form of dementia has been identified by Cambridge scientists. Fronto-temporal dementia (FTD) is the second most common type of dementia in the under 65s and can result in a complete personality change. The researchers studied the brains of 515 people with FTD and found the gene on chromosome 7. A charity said this could open the door to new treatments for the disease. Writing in the journal Nature, Professor Maria Grazia Spillantini, of the University of Cambridge, said her team had established an international collaboration with investigators in 11 countries including the UK, the US, Belgium and Spain. The Cambridge team compared the brains of 515 people with known FTD with 2,509 brains of people without the condition. They found several different mutations on chromosome 7 which are thought to affect around half of the people with FTD. These mutations increase the amounts of the protein the gene codes for. About 20% of individuals with FTD have another kind of genetic mutation known as a GRN mutation. Professor Spillantini thinks that the new gene accelerates the harm caused by the GRN mutation and makes the disease progress faster: "We found a specific gene that was associated with an increased risk of the disease. "A better understanding of how the gene is involved could identify a new approach to tackle this disease." (C)BBC

Keyword: Alzheimers; Genes & Behavior
Link ID: 13773 - Posted: 02.15.2010

Jennifer S. Altman A stand-up comedian, a ventriloquist who performs for children and a high school sophomore are among the people who share their stories about living with Tourette’s syndrome in the latest installment of Patient Voices. The often misunderstood condition can cause a range of tics, including sudden jerking movements, grunting, snorting and clearing the throat, which typically first appear during childhood. This week, Dr. Robert A. King and Dr. James F. Leckman of the Yale School of Medicine join the Consults blog to answer readers’ questions about Tourette’s syndrome. “Once thought to be a rare, severe and lifelong condition, Tourette’s is now known to be relatively common, affecting up to one percent of school-age children,” Dr. King says. “Symptoms are often mild and can spontaneously, and markedly, improve by later adolescence.” Dr. King is professor of child psychiatry and medical director of the Yale Child Study Center’s Tourette’s/Obessive-Compulsive Disorder Clinic. Dr. Leckman is the Neison Harris Professor of Child Psychiatry and Pediatrics at Yale, where he also serves as the center’s director of research. Both doctors have been intensively involved in the clinical care of individuals with Tourette’s syndrome and early onset obsessive-compulsive disorder for more than two decades. Do you have a question about Tourette’s syndrome? Post your comments and questions in the comments box below. Drs. King and Leckman will be responding to readers next week. Copyright 2010 The New York Times Company

Keyword: Tourettes
Link ID: 13772 - Posted: 06.24.2010

BY ERIC FERRERI, Staff Writer Kevin LaBar needed to provoke emotional highs in his research subjects. So the Duke neuroscientist turned to what else? A Duke/UNC basketball game. The result: a paper in an academic journal peeling back the cover on the brain's tendency to recall happy moments better than disappointing ones. LaBar and his research team took two dozen college-age men - half Duke fans, half UNC fans - and had them watch a Duke/UNC game from Feb. 3, 2000, a nail-biter at the Dean Smith Center that Duke pulled out 90-86 in overtime. "The question is, how do you ethically manipulate people's emotions to the extreme?" LaBar said. "A Duke/UNC rivalry is rife with emotion." The research subjects - who first had to prove their fan cred by filling out a college hoops questionnaire - watched the game three times in the course of the week. Then, they were put into an MRI machine and shown clips from the game that stopped just before the ball reached the hoop. The subjects were then quizzed on whether the shots went in or not. The conclusion: The UNC fans remembered more of the big shots the Tar Heels made. The Duke fans remembered more of the Blue Devil highlights. The explanation: A big, emotional moment in a game triggers a higher level of brain processing. Essentially, the brain works harder when something good happens. "It's like for the spectacular shot, you sort of put yourself in the shoes of the player," LaBar said. "And if your team isn't doing well, you kind of tune it out." © Copyright 2010, The News & Observer Publishing Company,

Keyword: Emotions; Learning & Memory
Link ID: 13771 - Posted: 06.24.2010

Delays at crucial points during the development of the brain in the womb may explain why people with a condition linked to autism do not like hugs. A study in mice with fragile X syndrome found wiring in the part of the brain that responds to touch is formed late. The findings may help explain why people with the condition are hypersensitive to physical contact, the researchers wrote in Neuron. It also points to key stages when treatment could be most effective. Fragile X syndrome is caused by a mutant gene in the X chromosome that interferes in the production of a protein called fragile X mental retardation protein (FMRP). Under normal circumstances, the protein directs the formation of other proteins that build synapses in the brain. Boys are usually more severely affected with the condition - which is the leading known cause of autism - because they have only one X chromosome. In addition to mental impairment, hyperactivity, emotional and behavioural problems, anxiety and mood swings, people with fragile X also show what doctors call "tactile defensiveness", which means they do not make eye contact and do not like physical contact and are hypersensitive to touch and sound. By recording electrical signals in the brains of mice, bred to mimic the condition, the researchers found that connections in the sensory cortex in the brain were late to mature. This "mistiming" may trigger a domino effect and cause further problems with the correct wiring of the brain, they concluded. The study also found these changes in the brain's connections occur much earlier than previously thought, midway through a baby's development in the womb. (C)BBC

Keyword: Autism; Genes & Behavior
Link ID: 13770 - Posted: 02.13.2010

Maybe everyone could use a gay uncle. A new study found that homosexual men may be predisposed to nurture their nieces and nephews as a way of helping to ensure their own genes get passed down to the next generation. Research has confirmed that male homosexuality is at least partly hereditary – it tends to cluster in families, and identical twin brothers of gay men are more likely to be gay than fraternal twin brothers, who do not share identical DNA. But scientists have been puzzled about how these genes are perpetuated, since homosexual males are less likely to reproduce than straight males. Basically, why haven't gay people gone extinct? One idea is called the "kin selection hypothesis." Perhaps gay men are biologically predisposed to help raise the offspring of their siblings and other relatives. "Maybe what's happening is they're helping their kin reproduce more by just being altruistic towards kin," said evolutionary psychologist Paul Vasey of the University of Lethbridge in Canada. "Kin therefore pass on more of the genes which they would share with their homosexual relatives." Vasey and his student Doug VanderLaan tested this hypothesis among a group of men called fa'afafine on the Pacific island of Samoa. Fa'afafine are effeminate men who are exclusively attracted to men as sexual partners, and are generally recognized and tolerated as a distinct gender category — neither male nor female. © 2010 LiveScience.com.

Keyword: Sexual Behavior; Evolution
Link ID: 13769 - Posted: 06.24.2010

By Adam Hadhazy As Olympians go for the gold in Vancouver, even the steeliest are likely to experience that familiar feeling of "butterflies" in the stomach. Underlying this sensation is an often-overlooked network of neurons lining our guts that is so extensive some scientists have nicknamed it our "second brain". A deeper understanding of this mass of neural tissue, filled with important neurotransmitters, is revealing that it does much more than merely handle digestion or inflict the occasional nervous pang. The little brain in our innards, in connection with the big one in our skulls, partly determines our mental state and plays key roles in certain diseases throughout the body. Although its influence is far-reaching, the second brain is not the seat of any conscious thoughts or decision-making. "The second brain doesn't help with the great thought processes…religion, philosophy and poetry is left to the brain in the head," says Michael Gershon, chairman of the Department of Anatomy and Cell Biology at New York–Presbyterian Hospital/Columbia University Medical Center, an expert in the nascent field of neurogastroenterology and author of the 1998 book The Second Brain (HarperCollins). Technically known as the enteric nervous system, the second brain consists of sheaths of neurons embedded in the walls of the long tube of our gut, or alimentary canal, which measures about nine meters end to end from the esophagus to the anus. The second brain contains some 100 million neurons, more than in either the spinal cord or the peripheral nervous system, Gershon says. © 2010 Scientific American

Keyword: Emotions
Link ID: 13768 - Posted: 06.24.2010

by Anil Ananthaswamy A SIGN of a cell's age could help predict the onset of dementia. Elderly people are more likely to develop cognitive problems if their telomeres - the stretches of DNA that cap the ends of chromosomes - are shorter than those of their peers. The shortening of telomeres is linked to reduced lifespan, heart disease and osteoarthritis. Telomeres naturally shorten with age as cells divide, but also contract when cells experience oxidative damage linked to metabolism. Such damage is associated with cognitive problems like dementia. Thomas von Zglinicki at Newcastle University, UK, showed in 2000 that people with dementia not caused by Alzheimer's tended to have shorter telomeres than people without dementia. To see if healthy individuals with short telomeres are at risk of developing dementia, Kristine Yaffe at the University of California, San Francisco, and colleagues, followed 2734 physically fit adults with an average age of 74. Yaffe's team tracked them for seven years and periodically assessed memory, language, concentration, attention, motor and other skills. At the start, the researchers measured the length of telomeres in blood cells and grouped each person according to short, medium or long telomeres. After accounting for differences in age, race, sex and education, the researchers found that those with long telomeres experienced less cognitive decline compared to those with short or medium-length telomeres (Neurobiology of Aging, DOI: 10.1016/j.neurobiolaging.2009.12.006). © Copyright Reed Business Information Ltd

Keyword: Alzheimers; Genes & Behavior
Link ID: 13767 - Posted: 06.24.2010