By CLAUDIA DREIFUS A cognitive neuroscientist, Ellen Bialystok has spent almost 40 years learning about how bilingualism sharpens the mind. Her good news: Among other benefits, the regular use of two languages appears to delay the onset of Alzheimer’s disease symptoms. Dr. Bialystok, 62, a distinguished research professor of psychology at York University in Toronto, was awarded a $100,000 Killam Prize last year for her contributions to social science. We spoke for two hours in a Washington hotel room in February and again, more recently, by telephone. An edited version of the two conversations follows. Q. How did you begin studying bilingualism? A. You know, I didn’t start trying to find out whether bilingualism was bad or good. I did my doctorate in psychology: on how children acquire language. When I finished graduate school, in 1976, there was a job shortage in Canada for Ph.D.’s. The only position I found was with a research project studying second language acquisition in school children. It wasn’t my area. But it was close enough. As a psychologist, I brought neuroscience questions to the study, like “How does the acquisition of a second language change thought?” It was these types of questions that naturally led to the bilingualism research. The way research works is, it takes you down a road. You then follow that road. Q. So what exactly did you find on this unexpected road? A. As we did our research, you could see there was a big difference in the way monolingual and bilingual children processed language. We found that if you gave 5- and 6-year-olds language problems to solve, monolingual and bilingual children knew, pretty much, the same amount of language. © 2011 The New York Times Company

Keyword: Language; Alzheimers
Link ID: 15382 - Posted: 05.31.2011

By Karen Weintraub When Kathryn Ham and Amy S. Schneider were diagnosed with diabetes as children decades ago, patients were routinely told the disease would rob them of their fertility and ravage their eyes, kidneys, and nerves. They would be dead within 15-20 years, doctors told devastated parents. Both women defied the predictions. Over a bowl of vegetable soup recently, Schneider, now 55, credited her success to “good doctoring, good parenting, good health, and good luck.’’ Disciplined living made the difference for Ham, 82, though she admits it’s sometimes “a pain in the neck’’ to check her blood sugar four times every day, inject insulin, and eat a careful diet. Now, the Joslin Diabetes Center in Boston is studying 650 long-term type 1 diabetes survivors — including Ham, diagnosed 74 years ago, and Schneider, diagnosed a half-century ago — to better understand how they have fared so well for so long. The lesson is: “Diabetes is a controllable disease,’’ said Dr. George L. King, Joslin’s research director. “With the right constellation of proactive activity, you can manage it.’’ The research project — which includes studies of genetics, proteins, family history, and stem cells — marks the first time such a large group of survivors has been examined with records going back decades. © 2011 NY Times Co.

Keyword: Obesity
Link ID: 15381 - Posted: 05.31.2011

By JoNel Aleccia Health writer Hundreds of reports of suicides, psychotic reactions and other serious problems tied to the popular stop-smoking drug Chantix were left out of a crucial government safety review because Pfizer Inc., the drug’s manufacturer, submitted years of data through “improper channels.” Some 150 suicides — more than doubling those previously known — were among 589 delayed reports of severe issues turned up in a new analysis by the non-profit Institute for Safe Medication Practices. “We’ve had a major breakdown in safety surveillance,” said Thomas J. Moore, the ISMP senior scientist who analyzed the data. The serious problems — including reports of completed suicides, suicide attempts, aggression and hostility and depression — had been mixed among some 26,000 records of non-serious side effects such as nausea and rashes, with some dating back to 2006, the year Chantix, or varenicline, was approved. They echo previous claims that the drug can induce extreme reactions in people trying to quit cigarettes, including vivid nightmares, crippling depression and sudden, violent outbursts. “It’s really chilling,” said Moore, who analyzed 26 Chantix reactions in a paper published in the September 2010 issue of the Journal of Pharmacotherapy. "This seems to unleash something in people. It can be violence to anything around." © 2011 msnbc.com

Keyword: Drug Abuse; Depression
Link ID: 15380 - Posted: 05.28.2011

Children who get insufficient sleep at night are more likely to become overweight, according to researchers in New Zealand. A study, published on the BMJ website, followed 244 children between the ages of three and seven. It said more sleep was linked to a lower weight, which could have important public health consequences. UK experts said there was "no harm" in drawing attention to the link between reduced sleep and ill health. The children were seen every six months when their weight, height and body fat were measured. Their sleeping habits and physical-activity levels were recorded at ages three, four and five. The researchers found that those children who had less sleep in their earlier years were at greater risk of having a higher Body Mass Index at age seven. This link continued even when other risk factors, such as gender and physical activity, were accounted for in their research. Suggested reasons for the link include simply having more time to eat and changes to hormones affecting appetite. BBC © 2011

Keyword: Sleep; Obesity
Link ID: 15379 - Posted: 05.28.2011

by Sara Reardon When Lemuel Gulliver, the protagonist in Jonathan Swift’s Gulliver’s Travels lands on Lilliput, he doesn’t think of himself as a giant. Instead, he assumes everyone around him is tiny. Now, a team of cognitive neuroscientists has shown that we’re all a bit like Gulliver. In a clever experiment, they tricked people into thinking that their size relative to other objects had changed and showed that subjects assumed it was the objects, not themselves, that had been transformed. Do people use their own bodies as meter sticks to estimate the size of things? Or are our brains capable of making such estimates without making comparisons to our bodies? To find out, cognitive neuroscientist Björn van der Hoort and colleagues at the Karolinska Institute in Stockholm recruited 198 volunteers and had them lie down with their legs in front of them so that they could see them. Each volunteer donned a headset that played a closed-circuit video of the legs of an adjacent mannequin. Using either his finger or a stick, Van der Hoort touched each volunteer’s leg, which the volunteer couldn’t see, while simultaneously touching the leg of the mannequin, which the volunteer could see. This combination of touch and sight was enough to dupe subjects into thinking the fake legs were their own: Van der Hoort could even make a subject sweat by cutting the mannequin’s legs with a knife. Then things got really weird. The researchers secretly replaced the mannequin legs either with huge legs 400 centimeters long, short ones only 80 centimeters long, or tiny doll legs 30 centimeters long. They dangled a block in front of the camera and asked the subjects to describe how big it was, using both words and gestures. If their new legs were tiny, subjects tended to overestimate the size of the block, whereas if their transformed legs were large, they underestimated the block’s size, typically erring by about 40%. © 2010 American Association for the Advancement of Science.

Keyword: Vision; Pain & Touch
Link ID: 15378 - Posted: 05.28.2011

Ewen Callaway By transforming cells from human skin into working nerve cells, researchers may have come up with a model for nervous-system diseases and perhaps even regenerative therapies based on cell transplants. The achievement, reported online today in Nature1, is the latest in a fast-moving field called transdifferentiation, in which cells are forced to adopt new identities. In the past year, researchers have converted connective tissue cells found in skin into heart cells2, blood cells3 and liver cells4. Transdifferentiation is an alternative to the cellular reprogramming that involves converting a mature cell into a pluripotent stem cell — one capable of becoming many types of cell — then coaxing the pluripotent cell into becoming a particular type of cell, such as neurons. Marius Wernig, a stem-cell researcher at Stanford University in California, and the leader of the study, says that skipping the pluripotency step could avoid some of the problems of making tissues from these induced pluripotent stem cells (iPSCs). The pluripotency technique can also take months to complete. Wernig's team sparked the imaginations of cellular reprogrammers last year, when it transformed cells taken from the tip of a mouse's tail into working nerve cells5. That feat of cellular alchemy took just three foreign genes – delivered into tail cells with a virus – and less than two weeks. "We thought that as it worked so great for the mouse, it should be no problem to work it out in humans," Wernig says. "That turned out to be wrong." © 2011 Nature Publishing Group,

Keyword: Stem Cells; Pain & Touch
Link ID: 15377 - Posted: 05.28.2011

by Helen Thomson FOR some people, seeing pain in someone else is more than emotionally distressing: they feel the pain in their own body too. Now some of the pathways involved have been identified. "Synaesthetic pain" occurs mainly in people who have lost a limb. Some amputees are already known to experience phantom limb pain - a feeling of pain in a limb that is no longer there - but synaesthetic pain is different. Rather than occurring spontaneously, it is triggered by observed or imagined pain. "When I hear my husband's power tools, or see a knife, I often get a sharp pain through my phantom leg," says Jane Barrett, who has experienced synaesthetic pain since losing her leg in a motorcycle accident. When we observe or imagine pain, it activates areas of the brain involved in the processing of real pain. This is called the mirror neuron system and is thought to help us to understand other people's actions and emotions. But the activation is not as strong as that caused by real pain because inhibitory mechanisms normally dampen the response. Bernadette Fitzgibbon at Monash University in Melbourne, Australia, and colleagues, think those inhibitory mechanisms are themselves inhibited in pain synaesthetes. They used EEG to record brain activity in eight amputees who experience both phantom and synaesthetic pain, 10 amputees who experience just phantom pain and 10 healthy people with no amputations while they looked at images of hands or feet in potentially painful and non-painful situations. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Emotions
Link ID: 15376 - Posted: 05.28.2011

by Jessica Griggs Reindeer see their world in glorious ultraviolet, helping them find food and avoid predators. Most mammals, including humans, see using light from the visible part of the spectrum; ultraviolet light, which has a shorter wavelength, is invisible. But not so reindeer, says Glen Jeffery of University College London. The frozen wastes of the Arctic reflect around 90 per cent of the UV light that hits them; snow-free land typically reflects only a few per cent. So Jeffery and colleagues wondered whether reindeers had adapted to their UV-rich world. In dark conditions, they shone LED lights of different wavelengths, including UV, into the eyes of 18 anaesthetised reindeers while recording with an electrode whether nerves in the eye fired, indicating that the light had been seen. The UV light triggered a response in the eyes of all the reindeer. "Since migrating to the Arctic 10,000 years ago, these animals have adapted incredibly quickly," says Jeffery. The team's experiments with a UV camera in the Arctic suggest why. They showed that urine – a sign of predators or potential mates – and lichens – a major food source for reindeers in the winter months – absorb UV light, making them appear black in contrast to the UV-reflecting snow. © Copyright Reed Business Information Ltd.

Keyword: Vision; Evolution
Link ID: 15375 - Posted: 05.28.2011

By Neil Bowdler Science reporter, BBC News A Californian team say they have managed to convert human skin cells directly into functioning brain cells. The scientists manipulated the process by which DNA is transcribed within foetal skin cells to create cells which behaved like neurons. The technique had previously been demonstrated in mice, says the report in Nature. It could be used for neurological research, and might conceivably be used to create brain cells for transplant. The scientists used genetically modified viruses to introduce four different "transcription factors" into foetal skin cells. These transcription factors play a role in the "reading" of DNA and the encoding of proteins within the cell. They found the introduction of these four transcription factors had the effect of switching a small portion of the skin cells into cells which functioned like neurons. Unlike other approaches, the process did not involve the reprogramming of the skin cells into stem cells, but rather the direct transformation of skin cells into neurons. BBC © 2011

Keyword: Pain & Touch; Stem Cells
Link ID: 15374 - Posted: 05.28.2011

By Devin Powell SEATTLE — About a year and a half after her stroke, a 36-year-old professor started to feel sounds. A radio announcer’s voice made her tingle. Background noise in a plane felt physically uncomfortable. Now Tony Ro, a neuroscientist at the City College of New York and the Graduate Center of the City University of New York, might have figured out the cause of this synesthesia. Sophisticated imaging of the woman’s brain revealed that new links had grown between its auditory part, which processes sound, and the somatosensory region, which handles touch. “The auditory area of her brain started taking over the somatosensory area,” says Ro, who used diffusion tensor imaging, which focuses on the brain’s white matter connections, to spot the change. This connection between sound and touch may run deep in the rest of us as well, Ro and colleagues said during presentations May 25 at a meeting of the Acoustical Society of America. Both hearing and touch, the scientists pointed out, rely on nerves set atwitter by vibration. A cell phone set to vibrate can be sensed by the skin of the hand, and the phone’s ring tone generates sound waves — vibrations of air — that move the eardrum. Elizabeth Courtenay Wilson, a neuroscientist who did not attend the Seattle meeting, has also seen strong connections between areas of the brain that process hearing and touch. “We’re suggesting that the ear evolved out of the skin in order to do more finely tuned frequency analysis,” adds Wilson, of Beth Israel Deaconess Medical Center in Boston. © Society for Science & the Public 2000 - 2011

Keyword: Hearing; Pain & Touch
Link ID: 15373 - Posted: 05.28.2011

Sandrine Ceurstemont, video producer In this video, Harry Potter can appear to pass through Dobby the elf, but it's not magic. The illusion, created by Arthur Shapiro and Gideon Caplovitz from the American University in Washington DC, is an example of the different ways our brain can link separate objects in a scene. When watching the video above, focus on the spot where Harry and Dobby meet during the collision. What do you see? The two figures should appear to bounce off each other and return their separate ways. Now take a look at the scene again, this time while looking at something just above the video but keeping the characters in your peripheral vision. This time, Harry and Dobby should appear to pass through each other, even though they are actually bouncing. We experience this phenomenon because our brain processes different features of a scene in parallel. Colour and motion, for example, are analysed separately, even though a moving coloured object would be perceived as a whole. In this case, it shows that features can bind to moving objects in different ways. Shapiro writes: The apparent transfer of features contradicts what would be expected from theories that propose that perception is guided by intelligent inferences about how objects behave in the world © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15372 - Posted: 05.28.2011

By Laura Helmuth 1. We use only 10 percent of our brains. This one sounds so compelling—a precise number, repeated in pop culture for a century, implying that we have huge reserves of untapped mental powers. But the supposedly unused 90 percent of the brain is not some vestigial appendix. Brains are expensive—it takes a lot of energy to build brains during fetal and childhood development and maintain them in adults. Evolutionarily, it would make no sense to carry around surplus brain tissue. Experiments using PET or fMRI scans show that much of the brain is engaged even during simple tasks, and injury to even a small bit of brain can have profound consequences for language, sensory perception, movement or emotion. True, we have some brain reserves. Autopsy studies show that many people have physical signs of Alzheimer’s disease (such as amyloid plaques among neurons) in their brains even though they were not impaired. Apparently we can lose some brain tissue and still function pretty well. And people score higher on IQ tests if they’re highly motivated, suggesting that we don’t always exercise our minds at 100 percent capacity. 2. “Flashbulb memories” are precise, detailed and persistent. We all have memories that feel as vivid and accurate as a snapshot, usually of some shocking, dramatic event—the assassination of President Kennedy, the explosion of the space shuttle Challenger, the attacks of September 11, 2001. People remember exactly where they were, what they were doing, who they were with, what they saw or heard. But several clever experiments have tested people’s memory immediately after a tragedy and again several months or years later. The test subjects tend to be confident that their memories are accurate and say the flashbulb memories are more vivid than other memories. Vivid they may be, but the memories decay over time just as other memories do. People forget important details and add incorrect ones, with no awareness that they’re recreating a muddled scene in their minds rather than calling up a perfect, photographic reproduction.

Keyword: Miscellaneous
Link ID: 15371 - Posted: 05.28.2011

By Laura Sanders Though autism and related disorders vary widely from person to person, certain brain changes may be at the root of the disorder. Changes in genes important for brain-cell development and function contribute to the poorly understood disorder, a study published online May 25 in Nature shows. Finding genetic contributors to the multifaceted disease might help scientists design better ways to treat it. “For us to be able to develop specific therapies that treat the cause, you have to understand the genetics,” says pediatrician and autism researcher Hakon Hakonarson of the Children’s Hospital of Philadelphia. In the study, a team led by Daniel Geschwind of UCLA analyzed post-mortem tissue from the brains of 19 people with autism and 17 without. Patterns of gene activity differed in the two types of brains, as measured by levels of RNA molecules, which shuttle information from DNA to the protein factories in cells. In the healthy brains, hundreds of genes behaved differently depending whether they were found in the frontal or the temporal region of the brain. But in the autistic brains, only a handful of genes acted differently in the two areas. This lack of distinction may be set on course very early in a child’s life, Geschwind says. Many of the genes identified by the research are important for brain development and behavior. What’s more, the changes in the autism spectrum disorder brains were very similar to each other. “It looks like there’s a common pathology in autism, which is a surprising thing,” Geschwind says. “In spite of having many different causes, there’s some shared convergence.” © Society for Science & the Public 2000 - 2011

Keyword: Autism
Link ID: 15370 - Posted: 05.26.2011

by Jim Giles YOU are playing a video game, and your avatar is creeping into a haunted house at the dead of night. Suddenly, you freeze in your chair. Something is crawling up your back... Whether this idea appeals or not, researchers at Disney have made such sensations possible by inventing a system that fools players into thinking that objects are moving against their skin. Their brainchild, known as Tactile Brush, creates the illusion of being touched by anything from falling rain to crawling insects. One of the illusions the team employs is called apparent tactile motion. If two vibrating objects are placed close together on skin in quick succession, people often experience this as a single vibration moving between the two points of contact. In a related illusion, known as a phantom tactile sensation, a pair of stationary vibrations is sensed as a single stimulus placed in between the two. Apparent motion has been around since the early 1900s and phantom sensation since 1957, but this is the first time anyone has used them to provide precise tactile feedback. Ali Israr and Ivan Poupyrev at Disney Research Pittsburgh studied these illusions with the help of volunteers who sat in a chair backed by a grid of 12 vibrating coils. By operating the coils in different sequences and at different intensities, they worked out how to induce the sensations of apparent motion and also persuade the volunteers that they were feeling extra coils that didn't exist, which creates a more realistic effect. Israr and Poupyrev incorporated these two illusions into software that controlled the coils, which convinced the person sitting in the chair that shapes were moving across their back. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 15369 - Posted: 05.26.2011

By Emily Chung, CBC News Blind people who navigate using clicks and echoes, like bats and dolphins do, recruit the part of the brain used by sighted people to see, a new study has found. While few blind people use echolocation — emitting a sound and then listening for the echo to get information about objects in the surroundings — some that do are so good at it that they can use the ability to hike, mountain bike and play basketball, said Melvyn Goodale, one of the co-authors of the study published Wednesday in PloS One. Daniel Kish, 43, went blind at the age of 13 months from retinoblastoma, the same eye cancer that affected the late Canadian musician Jeff Healey. Melvyn Goodale says Kish can't remember a time when he didn't echolocate, and seems to have taught himself at a very young age. "His parents say that when he was about 18 months old, they noticed he was making these clicking noises." Kish is now president of World Access for the Blind, a non-profit group based in Encino, Calif., that teaches echolocation or Flash Sonar, mobility and life skills to blind youth and adults. He has taught echolocation in many countries around the world, including Canada, the U.K., and India. Goodale, a psychology professor and the director of the Centre for Brain and Mind at the University of Western Ontario in London, Ont., said he was amazed by the abilities of the two blind men in the study. © CBC 2011

Keyword: Hearing; Vision
Link ID: 15368 - Posted: 05.26.2011

A man walks into a bar, catches a girl's eye, and immediately looks gloomy, moody and averts his eyes. The woman is overcome with sexual attraction. Not your usual love story but maybe a more realistic one. Turns out, a winning smile isn't the way to a woman's heart; men who swagger and look gloomy are more likely to set pulses raising. That's according to Jessica Tracy at the University of British Columbia, Canada, who asked more than 1000 adults to rate the sexual attractiveness of hundreds of photos of the opposite sex. The images showed men and women in various displays of happiness, with big smiles and puffed out chests or shameful glances, lowered heads and averted eyes. In an interview with UK newspaper The Daily Telegraph, co-author Alec Beall, also at British Columbia said: "We did not ask participants if they thought these targets would make a good boyfriend or wife - we wanted their gut reactions on carnal, sexual attraction." The study found that women were not attracted to smiling, happy men, preferring those who looked proud and powerful or moody and ashamed. In an interview with Reuters, Tracy said: "To the extent that men think that smiling is a good thing to do if they want to be found sexually attractive our findings suggest that's not the case." © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Emotions
Link ID: 15367 - Posted: 05.26.2011

By Rachael Rettner In a finding that won't surprise many mothers, a new study says breast-feeding may help secure the bond between mother and child. But the study also offers one explanation how: through a change in the mother's brain. The brains of breast-feeding mothers show a greater response to the sound of their babies' cries than do the brains of mothers who do not breast-feed, the study researchers say. This boost in brain activity is seen in brain regions associated with mothering behaviors. The finding adds to a growing list of the benefits of breast-feeding. Breast milk is considered the best source of nutrition for babies, and breast-feeding has been linked with better test scores and better health for the child later in life. The results suggest this brain activity facilitates greater sensitivity from the mother toward her infant as the baby begins to socially interact with the world, the researchers say. The study may help people to "recognize that it's important to support mothers who do want to breast-feed," said study researcher Pilyoung Kim, of the National Institute of Mental Health. © 2011 msnbc.com

Keyword: Attention; Sexual Behavior
Link ID: 15366 - Posted: 05.26.2011

By GRETCHEN REYNOLDS Why, as we grow older, do we forget where we parked the car, and could exercise sharpen our recall? Those questions, of considerable interest to any of us who possess a brain as well as those with cars, is motivating a series of remarkable new experiments by researchers at Johns Hopkins University and the Center for the Neurobiology of Learning and Memory at the University of California, Irvine, during which young and older volunteers watch pictures flash onto a screen, while the scientists watch their brains. Creating and accessing memories are complicated processes, with the specific physiological mechanisms still largely unknown. But, using brain scans, neuroscientists already have established that quite a bit of the electrical activity and blood flow associated with memory processing occurs in the dentate gyrus, a part of the brain within the hippocampus, a larger portion of the brain known to be involved with learning and thinking. So for their latest study, published this month in Proceedings of the National Academy of Sciences, the researchers used advanced magnetic resonance imaging machines to scan the dentate gyrus and other areas within the brains of people at the very moment that they were in the process of trying to create and store certain new memories. Specifically, the volunteers, wearing head sensors, were shown a series of pictures of everyday objects, like computers, telephones, pineapples, pianos and tractors, and asked to press a button indicating whether each object typically was found indoors or outside. © 2011 The New York Times Company

Keyword: Learning & Memory; Alzheimers
Link ID: 15365 - Posted: 05.26.2011

By SUSAN DOMINUS It was bedtime for Krista and Tatiana Hogan, and the 4-year-old twin girls were doing what 4-year-olds everywhere do at bedtime. They were stalling, angling for more time awake. Their grandmother, Louise McKay, who lives with the girls and their parents in Vernon, a small city in British Columbia, was speaking to them in soothing tones, but the girls resorted to sleep-deferring classics of the toddler repertory. “I want one more hug!” Krista said to their grandmother, and then a few minutes later, they both called out to her, in unison, “I miss you!” But in the dim light of their room, a night light casting faint, glowing stars and a moon on the ceiling, the girls also showed bedtime behavior that seemed distinctly theirs. The twins, who sleep in one specially built, oversize crib, lay on their stomachs, their bottoms in the air, looking at an open picture book on the mattress. Slowly and silently, in one synchronized movement, they pushed it under a blanket, then pulled it out again, then back under, over and over, seeming to mesmerize each other with the rhythm. Suddenly the girls sat up again, with renewed energy, and Krista reached for a cup with a straw in the corner of the crib. “I am drinking really, really, really, really fast,” she announced and started to power-slurp her juice, her face screwed up with the effort. Tatiana was, as always, sitting beside her but not looking at her, and suddenly her eyes went wide. She put her hand right below her sternum, and then she uttered one small word that suggested a world of possibility: “Whoa!” © 2011 The New York Times Company

Keyword: Attention; Development of the Brain
Link ID: 15364 - Posted: 05.26.2011

by Greg Miller Any would-be cure for Alzheimer’s disease or other brain disorder faces a daunting obstacle: the blood-brain barrier. This nearly impenetrable lining in the capillaries of the brain keeps out viruses and other bad guys, but it also denies entry to many potential drugs and other treatments. Now researchers have devised a way to trick one of the gatekeepers in this cellular defense system into escorting a potentially beneficial antibody into the brain. They report that their method can reduce levels of amyloid-β, the prime suspect in Alzheimer’s disease, by up to 50% in the brains of mice. The new strategy targets an enzyme that helps produce amyloid-β. Efforts to inhibit this enzyme, called β-secretase 1 (BACE1), with small molecule drugs have met with limited success so far, says Ryan Watts, a neurobiologist at the biotech company Genentech in South San Francisco, California, and one of the leaders of the new research. That’s partly because these drugs also interfere with other enzymes and cause side effects. A better strategy, Watts and colleagues reasoned, might be to target BACE1 with antibodies, immune system sharpshooters that can be designed to attack very specific molecular targets. There’s a big problem with that idea, though: antibodies are too big to cross the blood-brain barrier. To overcome that obstacle, the Genentech team tried a strategy first demonstrated about 20 years ago. It took advantage of the brain’s own mechanism for getting a necessary nutrient, iron, across the lining of endothelial cells that form the blood-brain barrier. Iron in the bloodstream is bound to a bulky molecule called transferrin. The endothelial cells have a receptor for transferrin that acts like a gatekeeper: When transferrin binds to a receptor on the blood side of the barrier, the endothelial cell transports it (and its iron cargo) to the other side and spits it out into the brain. © 2010 American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 15363 - Posted: 05.26.2011