Scan of human genome may provide important new tools for prevention and treatment Researchers at the Molecular Neurobiology Branch of the National Institute on Drug Abuse (NIDA), National Institutes of Health, have completed the most comprehensive scan of the human genome to date linked to the ongoing efforts to identify people most at risk for developing alcoholism. This study represents the first time the new genomic technology has been used to comprehensively identify genes linked to substance abuse. The study can be viewed online and will be published in the December 2006 issue of the American Journal of Medical Genetics Part B (Neuropsychiatric Genetics). “Tools such as pooled data genome scanning give us a completely new way of looking at complex biological processes, such as addiction,” says Dr. Elias A. Zerhouni, director of the National Institutes of Health. “The ability to pinpoint genes in the human genome responsible for disease has the potential to revolutionize our ability to treat and even prevent diseases.” “Previous studies established that alcoholism runs in families, but this research has given us the most extensive catalogue yet of the genetic variations that may contribute to the hereditary nature of this disease,” says NIDA Director Dr. Nora D. Volkow. “We now have new tools that will allow us to better understand the physiological foundation of addiction.”

Keyword: Drug Abuse; Genes & Behavior
Link ID: 9274 - Posted: 06.24.2010

Alcoholism can cause neuropsychological deficits, that much is clear. There is much less clarity, however, concerning to what degree recovery may occur with abstinence from alcohol. New findings indicate that long-term abstinence from alcohol can resolve many – but not all – neurocognitive deficits. Results are published in the September issue of Alcoholism: Clinical & Experimental Research. "Previous research has shown some but not total recovery with abstinence from alcohol," said George Fein, president of and senior scientist at Neurobehavioral Research, as well as the corresponding author for the study. "The continuing presence of deficits is not a trivial issue as it may interfere with day-to-day functioning." "The nature of alcoholism as a dynamic condition is largely underappreciated by most people, including clinicians," added Edith Sullivan, a professor in the department of psychiatry and behavioral sciences at Stanford University School of Medicine. "Alcoholics may have periods of abstinence, during which time they give their nervous system time for repair. Thus, longitudinal studies of alcoholics are critical for identifying functional areas that are targeted by alcoholism, those that are relatively spared, and those that can recover with sobriety."

Keyword: Drug Abuse
Link ID: 9273 - Posted: 06.24.2010

Boston, MA -- Socks in the sock drawer, shirts in the shirt drawer, the time-honored lessons of helping organize one's clothes learned in youth. But what parts of the brain are used to encode such categories as socks, shirts or any other item, and how does such learning take place? New research from Harvard Medical School (HMS) investigators has identified an area of the brain where such memories are found. They report in the advanced online Nature that they have identified neurons that assist in categorizing visual stimuli. They found that the activity of neurons in a part of the brain called the parietal cortex encode the category, or meaning, of familiar visual images and that brain activity patterns changed dramatically as a result of learning. Their results suggest that categories are encoded by the activity of individual neurons (brain cells) and that the parietal cortex is a part of the brain circuitry that learns and recognizes the meaning of the things that we see. "It was previously unknown that parietal cortex activity would show such dramatic changes as a result of learning new categories," says lead author David Freedman, PhD, HMS postdoctoral research fellow in neurobiology. "Some areas of the brain, particularly the frontal and temporal lobes, have been associated with visual categorization. Since these brain areas are all interconnected, an important next step will be to determine their relative roles in the categorization process."

Keyword: Vision
Link ID: 9272 - Posted: 08.28.2006

Michael Hopkin For the past two years, researchers have been hotly debating (and coming dangerously close to fighting over) whether the fossils of a diminutive hominin found in Indonesia are those of a previously unknown species. The publication this week of some long-standing doubts over the 'hobbit' fossils show the debate is far from over. The dispute over the bones of Homo floresiensis has involved allegations of name-calling, nationalistic motives, and wilfully damaging specimens. One camp insists that the tiny inhabitants of the Indonesian island of Flores were a unique species; the other claims that the bones are of a diseased Homo sapiens pygmy. As the debate rages, news@nature.com set out to find whether there will ever be an end to the conflict. The latest instalment came on Monday, with the publication in Proceedings of the National Academy of Sciences1 of doubts first raised by Indonesia's leading anthropologist, Teuku Jacob, of Gadjah Mada University, shortly after the finds were first published in 2004. Jacob and his colleagues cite a range of evidence that the 'hobbit' bones bear similarities to features found in various modern pygmies, including a Rampasasa pygmy from Flores who has a receding chin (the single complete hobbit skull features a jaw with no chin at all). ©2006 Nature Publishing Group

Keyword: Evolution
Link ID: 9271 - Posted: 06.24.2010

Hearing loss in the elderly has been linked to flaws in a specific gene in a study by Dutch researchers. About 37% of Britons aged 61 to 70 and 60% of those aged 71 to 80 - 6.5m people - have age-related hearing loss. The Human Mutation study of over 1,200 people found subtle changes in a gene called KCNQ4 were more common in those with age-related hearing problems. The Royal National Institute for Deaf People, which funded the work, said it offered "real hope for treatments." Age-related hearing loss is a complex condition, which scientists believe has both environmental and genetic causes. The most common environmental factor is noise exposure. Hearing loss makes it difficult for elderly people to communicate with friends and family, and can lead to them feeling increasingly isolated. There is currently is no way of identifying those at risk or preventing the onset of hearing loss. Scientists already know that a mutation in KCNQ4 is linked to hereditary hearing loss which happens early in life, regardless of exposure to noise and other environmental factors. In people with normal hearing, it is expressed in the hair cells of the cochlea where it helps recycle potassium, brought in to trigger a nerve signal to be sent to the brain, back into inner ear fluid. (C)BBC

Keyword: Hearing; Genes & Behavior
Link ID: 9270 - Posted: 08.27.2006

PARENTING has obvious effects on mothers, but fathers appear to be affected, too. A study published this week shows that fatherhood increases the nerve connections in the region of the brain that controls goal-driven behaviour—at least, it does in marmosets. Pregnancy and motherhood have long been known to bring about changes—many of them positive—to the female brain. Pregnant and nursing rats have a greater number of neural connections, particularly in the region of the brain that controls hormones and maternal behaviour. The brain changes coincide with improvements in spatial memory and speedier foraging skills, which might help a mother rat protect and feed her young. Just what effect parenting might have on the brains of fathers has remained an open question, however. Male rats sometimes eat their young rather than nurture them, which makes them a poor model for studying how fatherhood affects the brains of species that frown on infanticide. Marmoset fathers on the other hand are a model of paternal devotion. They carry their babies for more than half the time during the offspring's first three months, passing them to the mother only when the babies need to be fed. Elizabeth Gould of Princeton University and her colleagues compared the brains of marmoset fathers with those of males that lived in mated pairs, but lacked offspring. They found substantial differences. The nerve cells in the prefrontal cortex of fathers had more tiny projections, known as dendritic spines, than those of non-fathers. © The Economist Newspaper Limited 2006

Keyword: Sexual Behavior
Link ID: 9269 - Posted: 06.24.2010

Montreal, -- A new breed of permanently 'cheerful' mouse is providing hope of a new treatment for clinical depression. TREK-1 is a gene that can affect transmission of serotonin in the brain. Serotonin is known to play an important role in mood, sleep and sexuality. By breeding mice with an absence of TREK-1, researchers were able create a depression-resistant strain. The details of this research, which involved an international collaboration with scientists from the University of Nice, France, are published in Nature Neuroscience this week. "Depression is a devastating illness, which affects around 10% of people at some point in their life," says Dr. Guy Debonnel an MUHC psychiatrist, professor in the Department of Psychiatry at McGill University, and principal author of the new research. "Current medications for clinical depression are ineffective for a third of patients, which is why the development of alternate treatments is so important." Mice without the TREK-1 gene ('knock-out' mice) were created and bred in collaboration with Dr. Michel Lazdunski, co-author of the research, in his laboratory at the University of Nice, France. "These 'knock-out' mice were then tested using separate behavioral, electrophysiological and biochemical measures known to gauge 'depression' in animals," says Dr. Debonnel. "The results really surprised us; our 'knock-out' mice acted as if they had been treated with antidepressants for at least three weeks." This research represents the first time depression has been eliminated through genetic alteration of an organism. "The discovery of a link between TREK-1 and depression could ultimately lead to the development of a new generation of antidepressant drugs," noted Dr. Debonnel.

Keyword: Depression
Link ID: 9268 - Posted: 08.27.2006

An enzyme that helps neurons rid themselves of excess or aberrant proteins is required for normal brain function, according to a new report in the August 25, 2006 issue of the journal Cell, published by Cell Press. What's more, by increasing brain levels of the enzyme in mice with Alzheimer's symptoms, the researchers found they could reverse lapses of memory characteristic of the debilitating disease. Treatments that elevate the protein, known as ubiquitin C-terminal hydrolase L1 (Uch-L1), might therefore have potential as a new therapy for Alzheimer's disease, according to the researchers. Currently available therapies have almost exclusively targeted amyloid beta (Aß), the protein responsible for the "amyloid plaques" that riddle the brains of patients with Alzheimer's disease, they added. "By injecting what is essentially a Uch-L1 drug to raise its levels in the brain, we were able to restore a great deal of brain activity in a transgenic mouse model of Alzheimer's disease," said Michael Shelanski of Columbia University. "While amyloid beta is certainly a key player in Alzheimer's disease--and efforts to reduce it remain a worthy goal--our results show that, even in the presence of the plaque, damage to memory can be reversed." The findings suggest that neurons' protein-ridding machinery, the so-called ubiquitin/proteasomal pathway, may play an important early role in the pathogenesis of Alzheimer's disease, he added.

Keyword: Alzheimers; Learning & Memory
Link ID: 9267 - Posted: 08.27.2006

Lucy Heady Researchers have worked out how a mammal's tongue detects sour tastes: it's all down to a single, specialized receptor, they say. Taste in mammals is classified into sweet, salty, bitter, sour and umami (the taste of monosodium glutamate, commonly found in Chinese takeaways). Until now, only the sweet, bitter and umami taste receptors had been identified, and researchers were unsure whether the other two tastes had specialized receptors for them at all. The three tastes with known receptors are triggered by large molecules, such as sucrose, that latch on to and are recognized by specialized cells on the tongue. But salty and sour are different in that they are the tastes of very simple ions: hydrogen ions (H+) for acidity and, mainly, sodium ions (Na+) for salt. Some researchers have speculated that many cells in the tongue might be able to pick up these signals, relaying the information in a complex pattern of nerve signals to the brain. "This kind of model is very messy," says Charles Zuker of the Howard Hughes Medical Institute in San Diego. So Zuker's team — the same lab that pinned down the previous three taste receptors — set out to hunt for a sour taste receptor. Angela Huang, a graduate student in Zuker's lab, first trawled through the mouse genome to pick out any proteins that exist in cell membranes: proteins that can pick up signals from the outside world and transmit them to nerves. That left about 10,000 candidates. ©2006 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9266 - Posted: 06.24.2010

Tracy Staedter, Discovery News — A wearable computer system that emits audio cues could help guide the visually impaired. The System for Wearable Audio Navigation, or SWAN, combines global positioning system (GPS) technology with cameras and image processing software to locate a person's whereabouts and "see" details such as windows, doors and corners. "In the future, we could even use the cameras to recognize people or objects," said Frank Dellaert, who developed the system at the Georgia Institute of Technology with Bruce Walker. The technology could do everything from lead a blind person through a new neighborhood to help firefighters or soldiers plot a course in darkness. Since about 2001, visually impaired people have had access to commercial GPS-based navigation systems meant to help them get around. The technology is available on handheld electronic devices such as laptops or PDAs and is similar to that used in cars. A GPS sensor pinpoints the person on a grid, while the computer's database — which contains street names as well as businesses — matches the information to the location. Copyright © 2006 Discovery Communications Inc.

Keyword: Vision; Robotics
Link ID: 9265 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. Most people reach their sexual peak at a time when, to put it charitably, they don’t always make the best use of their libido. My patient Dan, a 53-year-old in perfect physical health, refers to this as biology’s cruel joke, meaning now that he really knows what he wants in life, he would love to recapture some of his youthful sexual vigor and put it to good use. After years of psychotherapy, he had never felt more satisfied: he was at his pinnacle professionally and had a wife and three children whom he clearly adored. One day in therapy he asked me, “Do you think I could get some Viagra?” I don’t consider myself the least bit puritanical, but I’m usually in the business of making the sick better, not making the normal better than well. When I asked him why, he admitted there was no problem; he just wanted to jazz things up. “Is your wife complaining about sex?” I asked. “Oh, no, she seems very happy with the status quo. We have sex about once a week and maybe more on vacation,” he said. “Besides, what’s the harm? So many of my friends use Viagra for a security blanket or a boost.” Copyright 2006 The New York Times Company

Keyword: Sexual Behavior
Link ID: 9264 - Posted: 06.24.2010

By JAMES GORMAN As humans age, so I’m told, they tend not to sleep as well as they once did. There are all sorts of reasons — aches and pains, worries about work, and lifelong accumulations of sins that pretty much rule out the sweet sleep of innocence. Not as a cause of insomnia. What about the problems fruit flies have sleeping? Yes, Drosophila melanogaster also suffer sleep disruption when they get older. And a report on the troubled sleep of drosophila is being published in The Proceedings of the National Academy of Sciences. This is the kind of science that makes you wonder. For instance, are the female flies suffering from hot flashes? Are the male flies getting up to go to the bathroom three or four times a night? Of course not. Fruit flies don’t have bathrooms. Or you may wonder what troubles are keeping the flies up. They don’t have to worry about family values, illegal immigration or debt. They don’t have families or money. And given the ubiquity of fruit and of scientific research, I’m guessing drosophila, bless their little genomes, must benefit from something close to full employment. Copyright 2006 The New York Times Company

Keyword: Evolution; Sleep
Link ID: 9263 - Posted: 06.24.2010

WHAT'S the difference between the male and female brain? Ah, if only we had a dollar for every one-liner that has been spawned by that little poser. An entire industry of books, films, key fobs and stand-up comedians owes its existence to the rich seam of humour that can be mined from the disparity between the sexes. Why is psychoanalysis quicker for men than for women? Because when it's time to go back to childhood, he's already there. Why does a man have a hole in his penis? So the air can get to his brain. What's the main difference between women and men? Women can use sex to get what they want; men can't because sex is what they want. Ha, ha, ha. But when science asks the same question, we seem to lose our sense of humour. Experts who point to biological differences in the male and female brain as a way of explaining behaviour are seen by some as shattering taboos and reinforcing stereotypes. To some, to look for differences is to look for ways to discriminate against women. Louann Brizendine, an American neuropsychiatrist, knows that she will take some flak when her new book, The Female Brain, is published later this month. In Newsweek, she describes the book as a "kind of owner's manual for women" and in it discusses what she believes are the biological reasons that girls gravitate to dolls and boys gravitate to trucks, and which hormones drive teenage girls to become obsessed with shopping and sending mobile phone text messages. © The Australian

Keyword: Sexual Behavior
Link ID: 9262 - Posted: 06.24.2010

ST. PAUL, Minn. -- Children with autism have altered brain anatomy thought to be due to abnormal brain development, according to a study published in the August 22, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology. The study compared 60 autistic children to 16 children with developmental delay and 10 children with typical development. All of the children were age two to four. Using magnetic resonance imaging scans (MRI), the researchers measured the transverse relaxation (T2) of cortical gray and white matter in the children's brains. T2 relaxation is a measure of how tightly bound, or mobile, water is in brain tissue and has been used to measure the temporal progression of brain maturation. The researchers found that the autistic children had differences in the gray matter of their brains compared to the children with typical development. "One of the more consistent brain findings associated with autism has been enlarged brain size," said study author Stephen Dager, MD, of the University of Washington School of Medicine in Seattle. "In contrast to current theories which suggest the enlarged brains are due to accelerated early growth tied to a more advanced stage of brain maturation, gray matter T2 relaxation findings were in the opposite direction. These results suggest that the mechanism or mechanisms responsible for larger brains in autism are different from more rapid growth."

Keyword: Autism; Development of the Brain
Link ID: 9261 - Posted: 08.22.2006

Jennifer Viegas, Discovery News — The horn-like jaws of the trap-jaw ant snap shut at a speed of 78 to 145 mph, qualifying as the fastest known moving body parts, according to new research. The jaws snap together with a force strong enough to hurl the ant 3 inches into the air and 8 1/2 inches away, the equivalent of a 5’6" human jumping 44 feet in the air and soaring for 132 feet. "The ants generate their extreme (jaw) speeds through the use of power amplification – a combination of springs and latches which allow the animals to store up and release energy within their own body," said lead author Sheila Patek, who indicated that the system has an "internal damping" mechanism that prevents the powerful snap from crushing the ant. "Trap-jaw ants slowly contract large muscles while a pair of latches keep the jaws open. Once the muscles are fully contracted, the latches are released and the jaws close explosively," she explained to Discovery News. The findings are published in this week’s Proceedings of the National Academy of Sciences. © 2006 Discovery Communications Inc.

Keyword: Miscellaneous
Link ID: 9260 - Posted: 06.24.2010

In this study, Ann Halbower and colleagues from Johns Hopkins University School of Medicine looked at 19 children aged 6-16 y with OSA and compared them with 12 healthy controls. The children underwent sleep tests, a battery of neuropsychological assessments, including IQ tests, and tests of executive function, and a group of children were assessed by magnetic resonance spectroscopy, a special form of brain imaging. Children with OSA had significantly lower scores than matched controls on full scale IQ tests and significantly lower performance on measures of executive function, including verbal working memory (sentence span) and word fluency. The special brain imaging (proton magnetic resonance spectroscopic imaging) showed decreases in the mean neuronal metabolite ratio of N-acetyl aspartate/choline in the left hippocampus and right frontal cortex, indicating possible neuronal injury in these areas. Symptomatic childhood sleep-disordered breathing includes a range of conditions in which children have difficulties with breathing when they are asleep. The conditions range from simple snoring to the most severe condition, obstructive sleep apnea (OSA). In children, OSA may be associated with enlarged tonsils, long-term allergy, or obesity. About two in every hundred children have OSA. The symptoms of OSA are loud snoring at night, disrupted, restless sleep, undue tiredness, and difficulties in concentration. If untreated, researchers believe that it may lead to a number of long-term problems with health and learning.

Keyword: Sleep; Intelligence
Link ID: 9259 - Posted: 08.22.2006

Kerri Smith Here's a cool strategy for relieving pain: scientists have found that cold temperatures and even cool-sensation chemicals can be used to treat chronic pain. Cold wet cloths and mint leaves pressed to the temple have long been used to put a damper on pain. But aside from the general numbing effect that ice can have on nerves, how cooling treatments work has remained a mystery. Now that the mechanism has been unpicked, researchers say, it could give new hope to sufferers of chronic pain, an often intractable condition affecting 50 million people in the United States alone. Some nerve-ends in the skin are known to hold receptors that are sensitive to temperature changes as well as foods frequently described as hot (such as chilli) or cold (such as menthol). One of these receptors, called TRPM8, can help the body to monitor temperatures between about 8 and 12 °C, as well as being activated by menthol-like chemicals, including a super-cooling chemical called icilin. Susan Fleetwood-Walker of the University of Edinburgh, UK, decided to investigate the link between these cold receptors and pain in rats. They first induced chronic pain in their animals by tying a thread around a thigh, and then either injected a very small dose of icilin into the spinal cord or had the rats stand in a shallow bath of the chemical. They then stroked the painful limb and checked the rats' response: those treated with icilin could withstand three times as much pressure. The findings are reported in Current Biology1. ©2006 Nature Publishing Group

Keyword: Pain & Touch
Link ID: 9258 - Posted: 06.24.2010

By LISA SANDERS, M.D. The white-haired man looked up from his newspaper as the doctor entered the hospital room. His eyes were a bright blue, and a warm, somewhat crooked smile lit up his face. “Sorry I can’t stand,” he said gallantly after the doctor introduced herself. “My legs are weak.” Dr. Merceditas Villanueva, a specialist in infectious diseases, returned the smile, then asked the patient to tell her about the weakness. He was 77. Never sick a day in his life — until the week before, on the Fourth of July. That day, also his wife’s birthday, the patient’s children and grandchildren had come to spend the day at his pool. In the late afternoon, the patient tried to get up to start the family dinner. “I do most of the cooking, especially on the holidays,” he told her in his lightly accented voice. “I’m Hungarian, and I like to cook the foods from home.” But that afternoon he was surprised to find that getting out of his chair was strangely difficult. He struggled to his feet, shrugging off the sons who hurried to help, and made his way slowly to the kitchen. But he hadn’t been able to cook that night — or any night since then. By the end of the week, he had no strength at all. “I couldn’t even take a step,” he said. “I was helpless.” His face eased into his lopsided smile once more. “My wife insisted I come to the hospital.” In the meantime, he also developed pain and swelling in his right knee, his left elbow and both feet. But, the patient added, joint pain was nothing new. The weakness, though, had never happened before; that was a little worrisome. Copyright 2006 The New York Times Company

Keyword: Miscellaneous
Link ID: 9257 - Posted: 06.24.2010

By GRETCHEN REYNOLDS Six years ago, Dr. Paul Savage was a pudgy mess. A 38-year-old emergency-room director in Waukegan, Ill., he weighed 267 pounds, suffered from high blood pressure and shortness of breath and had sallow skin that drooped in wattles around his chin. Today, at 44, he’s a new, unrecognizable man. Almost 100 pounds lighter, he boasts 12 percent body fat, a superhero jaw line and skin tone that seems almost incandescent. Savage says he owes much of his transformation to the self-administration of human growth hormone (H.G.H.). “I worked with a personal trainer and a nutritionist first,” he says. “I actually gained three pounds. Then I started growth hormone, and the weight dropped away.” Like a freshly hatched evangelist, Savage quit emergency-room medicine and in 2004 co-established a clinic in Chicago dedicated to hormone therapy, with an emphasis on H.G.H. His franchise, which operates under the name BodyLogicMD, serves about 1,500 people nationwide, many of whom pay upward of $15,000 for a yearly cycle of growth-hormone injections. The patient count rises by almost 100 each month. According to a 2005 article in The Journal of the American Medical Association, human growth hormone is being prescribed to tens of thousands of people each year at anti-aging or “age management” facilities like Savage’s. Those who take H.G.H. — including many doctors — say it can restore sagging physiques, flagging endurance and wilting libidos as well as cure depression and sharpen mental acuity. “I can’t believe everybody isn’t taking this,” says Dr. Darren Clair, 53, the founder of Vibrance Health Services, an age-management clinic in Beverly Hills, Calif., and himself a dedicated H.G.H. user. No one has yet claimed that H.G.H. reduces foot odor and freshens breath, though that could be coming. Copyright 2006 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 9256 - Posted: 06.24.2010

The compelling urge to satisfy one's hunger enlists structures throughout the brain, as might be expected in a process so necessary for survival. But until now, studies of those structures and of the feeding cycle have been only fragmentary--measuring brain regions only at specific times in the feeding cycle. Now, however, Ivan de Araujo, Duke University Medical Center, and colleagues report they have mapped the activity of whole ensembles of neurons in multiple feeding-related brain areas across a full cycle of hunger-satiety-hunger. Their findings, reported in the August 17, 2006, issue of the journal Neuron, published by Cell Press, open the way to understanding how these ensembles of neurons integrate to form a sort of distributed "code" that governs the motivation that drives organisms to satisfy their hunger. In their paper, Ivan de Araujo and colleagues implanted bundles of infinitesimal recording electrodes in areas of rat brain known to be involved in feeding, motivation, and behavior. Those areas include the lateral hypothalamus, orbitofrontal cortex, insular cortex, and amygdala. The researchers then recorded neuronal activity in those regions through a feeding cycle, in which the rats became hungry, fed on sugar water to satisfy that hunger, and then grew hungry again.

Keyword: Obesity
Link ID: 9255 - Posted: 08.21.2006