by Catherine Brahic Sexual stereotypes are not the preserve of humans. Male dolphins, it seems, are not interested in learning how to use a sponge, but their sisters are. Dolphins were first seen carrying sponges cupped over their beaks in Shark Bay, Australia, in the 1980s. Janet Mann of Georgetown University in Washington, DC, and colleagues have now reviewed data collected during 20 years spent monitoring this group of dolphins and found that, while mothers show both their male and female calves how to use sponges, female calves are almost exclusively the only ones to apply this knowledge. "The daughters seem really keen to do it," says Mann. "They try and try, whereas the sons don't seem to think it's a big deal and hang out at the surface waiting for their mothers to come back up." Solitary spongers Sponger dolphins shuffle their beak around in the sand, apparently using the sponge as protection. When they ferreted out a hidden fish, the dolphins drop the sponge and catch the prey. The researchers even dived down with sponge-capped hands and tried the technique themselves - successfully ferreting out spotted grubfish. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Sexual Behavior
Link ID: 12323 - Posted: 06.24.2010

By Morten L. Kringelbach and Tipu Z. Aziz The video is brief, just a couple of minutes, but it’s reality TV as riveting as anything you’ll ever see. A man in his mid-50s, affable, articulate, faces the camera and talks a bit about a medical procedure he’s had. He holds in his hand what looks like a remote control. “I’ll turn myself off now,” he says mildly. The man presses a button on the controller, a beep sounds, and his right arm starts to shake, then to flap violently. It’s as if a biological hurricane has engulfed him, or perhaps it’s that his arm is made of straw and some evil sprite is waving it about. With effort, the man grasps the malfunctioning right arm with his left hand and slowly, firmly, subdues the commotion, as if he were calming a child in the throes of a temper tantrum. He’s breathing hard, and it’s clear he can’t keep it up much longer. With an almost desperate gesture, he reaches out for the controller and manages to press the button again. There’s a soft beep, and suddenly it’s over. He’s fine. Composed, violently afflicted, then composed again. All with the flick of a switch. As before-and-after moments go, this one is potent, verging on the miraculous. It’s the kind of thing you’d expect to witness under a revival tent, not in the neurology ward of a British hospital. Once you’ve seen it, you’ll have an indelible image of Parkinson’s disease. The word “tremor” doesn’t convey what can happen to people—the way they are thrashed and harassed by their own bodies. But this scene, involving a patient of ours, informs viewers about more than a disease; it’s a vivid window onto a powerful medical technology known as deep-brain stimulation (you can watch the video at www.kringelbach.dk/nrn). © 1996-2008 Scientific American Inc.

Keyword: Parkinsons; Depression
Link ID: 12322 - Posted: 06.24.2010

By Elizabeth Landau (CNN) -- For one person, the idea of spending a cold winter's night alone seems great -- a perfect time to catch up on novels, watch cheesy movies, and drink hot chocolate with marshmallows. For another, the prospect is less comforting -- feelings of depression, anger, isolation set in as the hours go by. About 60 million people in the U.S. feel so isolated that it's a major source of unhappiness. About 60 million people in the U.S. feel so isolated that it's a major source of unhappiness. Research suggests that the degree of loneliness that any two people feel in a particular situation may vary widely, partly because of genetics. In fact, loneliness is half inherited, half environmental, says John Cacioppo, director of the University of Chicago's Center for Cognitive and Social Neuroscience. In his recent book "Loneliness," with co-author William Patrick, Cacioppo defines loneliness in terms of the need for social connection and notes that a person can feel lonely even in a large crowd. At any given time, about 60 million people in the U.S. feel so isolated that it's a major source of unhappiness, the book says. "Loneliness we see to be much more like hunger, thirst and pain than a personality factor per se," Cacioppo told CNN. "It's something everybody has, everybody has the capacity to feel that way, and it serves to call attention to a real biological need." © 2008 Cable News Network

Keyword: Emotions; Genes & Behavior
Link ID: 12321 - Posted: 06.24.2010

Scientists believe a transplant of brain cells may one day be able to reverse a common form of hearing loss. Damage to hair cells in the inner ear due to ageing and overstimulation causes hearing problems in 10% of people worldwide. The cell loss is irreversible, but US scientists believe it may be possible to replace them with stem cells from a region of the brain. The study appears in Proceedings of the National Academy of Sciences. The key ependymal cells come from the lining of the lateral ventricle of the brain. They share characteristics with inner ear hair cells - but crucially, unlike them, they have the ability to reproduce. The researchers, led by Dr Dongguang Wei, from the University of California at Davis, believe the brain cells could potentially be transplanted from a person's brain into their ear, where they would take on the role of hair cells, and restore hearing. Loss of inner ear hair cells often also leads to breakdown of the nerve cells along which the signals they generate are transmitted to the brain. The researchers believe these spiral ganglion cells can also be replaced - this time by stem cells from another area of the brain's lateral ventricle. Their conclusions are based on a detailed analysis of the structure, chemistry and role of the brain cells. Tests of the theory are already underway in the laboratory. And they believe the cells also hold out hope for use in the treatment of diseases of the nervous system. Professor Andy Forge, of the University College London Ear Institute, said previous work had suggested that the inner ear might have a small number of stem cells of its own which might be able to replace damaged hair cells. (C)BBC

Keyword: Hearing; Regeneration
Link ID: 12320 - Posted: 12.09.2008

By GINA KOLATA Cheryl Weinstein’s left knee bothered her for years, but when it started clicking and hurting when she straightened it, she told her internist that something was definitely wrong. It was the start of her medical odyssey, a journey that led her to specialists, physical therapy, Internet searches and, finally, an M.R.I. scan that showed a torn cartilage and convinced her that her only hope for relief was to have surgery to repair it. But in fact, fixing the torn cartilage that was picked up on the scan was not going to solve her problem, which, eventually, she found was caused by arthritis. Scans — more sensitive and easily available than ever — are increasingly finding abnormalities that may not be the cause of the problem for which they are blamed. It’s an issue particularly for the millions of people who go to doctors’ offices in pain. The scans are expensive — Medicare and its beneficiaries pay about $750 to $950 for an M.R.I. scan of a knee or back, for example. Many doctors own their own scanners, which can provide an incentive to offer scans to their patients. And so, in what is often an irresistible feedback loop, patients who are in pain often demand scans hoping to find out what is wrong, doctors are tempted to offer scans to those patients, and then, once a scan is done, it is common for doctors and patients to assume that any abnormalities found are the reason for the pain. Copyright 2008 The New York Times Company

Keyword: Pain & Touch; Brain imaging
Link ID: 12319 - Posted: 06.24.2010

By JANE E. BRODY Michael became hooked on headphones in his early teens. He walked the streets of Brooklyn day after day with his favorite music blasting directly into his ears. By his early 20s, the sensory hair cells in his inner ears had been permanently damaged and Michael had lost much of his upper-range hearing. The Children’s Hearing Institute reports that hearing loss among children and young adults is rising in the United States, and that one-third of the damage is caused by noise. According to the American Academy of Audiology, about one child in eight has noise-induced hearing loss. That means some five million children have an entirely preventable disability that will stay with them for life. The academy has begun a “turn it to the left” (the volume dial, that is) awareness campaign in hopes of protecting current and future generations of youngsters from unwittingly damaging their hearing. Often, the problem is not detected until children develop persistent ringing in the ears or begin to have learning or behavior problems in school because of trouble understanding speech. Copyright 2008 The New York Times Company

Keyword: Hearing
Link ID: 12318 - Posted: 06.24.2010

By NATALIE ANGIER Imagine you’re in a dark room, running your fingers over a smooth surface in search of a single dot the size of this period. How high do you think the dot must be for your finger pads to feel it? A hundredth of an inch above background? A thousandth? Well, take a tip from the economy and keep downsizing. Scientists have determined that the human finger is so sensitive it can detect a surface bump just one micron high. All our punctuation point need do, then, is poke above its glassy backdrop by 1/400,000th of an inch — the diameter of a bacterial cell — and our fastidious fingers can find it. The human eye, by contrast, can’t resolve anything much smaller than 100 microns. No wonder we rely on touch rather than vision when confronted by a new roll of toilet paper and its Abominable Invisible Seam. Biologically, chronologically, allegorically and delusionally, touch is the mother of all sensory systems. It is an ancient sense in evolution: even the simplest single-celled organisms can feel when something brushes up against them and will respond by nudging closer or pulling away. It is the first sense aroused during a baby’s gestation and the last sense to fade at life’s culmination. Patients in a deep vegetative coma who seem otherwise lost to the world will show skin responsiveness when touched by a nurse. Copyright 2008 The New York Times Company

Keyword: Pain & Touch
Link ID: 12317 - Posted: 06.24.2010

By Michael Price Rod cells in our eyes help us see in dim light. They also ensure that the cones, the other light-sensitive cells we depend on for vision, get enough food, a new study reveals. The findings may shed light on a common cause of blindness. Approximately 100,000 people in the United States have retinitis pigmentosa, an incurable inherited retinal disease that leads to blindness. More than 40 genes can contribute to the disease, often by damaging important proteins in retinal cells. The disease's initial symptom, night-vision loss, appears when rods start dying off. This attrition usually begins in childhood, and though it's inconvenient, most people get by with their cones--the photoreceptive cells that work in bright light. But by the time affected people reach adulthood, the cones begin dying, too, ultimately resulting in total blindness. This has confounded scientists, because the faulty genes aren't active in the cones, only in the rods. To crack this mystery, biologist Constance Cepko of Harvard University and her colleague Claudio Punzo, a postdoctoral researcher, first evaluated previous theories. Some researchers thought that when the rods died, they produced a toxin that killed the cones. Others hypothesized that because rods use lots of oxygen in the retina, their death might leave behind a large amount of oxygen that overloads and damages the remaining cones. But neither of these seemed to fit the pattern, Cepko says, so he and Punzo decided to look for a new explanation. © 2008 American Association for the Advancement of Science.

Keyword: Vision
Link ID: 12316 - Posted: 06.24.2010

by Nora Schultz A dog might be a man's best friend, but only if it is being treated fairly. When a dog thinks it's getting a raw deal in comparison to other dogs, it doesn't shy away from expressing its envy. Until now, such overt dislike of unfairness had only been demonstrated in primates, but some scientists have suspected that other species that live cooperatively could also be sensitive to fair play - or a lack of one. To test this theory, Friederike Range and her colleagues at the University of Vienna, Austria, asked 43 trained dogs to extend their paw to a human in various situations. The animals performed the trick almost at every request, regardless of whether they were given a reward or not; as well as when working alone or alongside another dog. The dogs' enthusiasm quickly waned, though, when they saw the other dog being rewarded but received nothing themselves. The dogs that were ignored extended their paws significantly less often than in all other circumstances, doing so in only 13 out of 30 trials. They also showed significantly more symptoms of stress, such as licking or scratching themselves. © Copyright Reed Business Information Ltd

Keyword: Emotions; Evolution
Link ID: 12315 - Posted: 06.24.2010

By BENEDICT CAREY A long-awaited government report is calling on the military to test all new recruits for cognitive skills and then do large-scale studies of returning combat veterans to better evaluate and respond to traumatic brain injury, the signature wound of the Iraq war. For years, veterans’ advocates and researchers have called for more careful investigation of head injuries — not just severe wounds but also “closed head” injuries, which do not produce visible damage and do not show up on CT scans. Some doctors and veterans say the high blast impact of I.E.D.’s, the roadside explosives that have accounted for most head injuries to troops in Iraq, may be creating symptoms that differ from the sort of concussions suffered in sports or car accidents. Many veterans have complained of persistent, sometimes disabling symptoms like sleeplessness, dizziness and confusion that can resemble disorders like post-traumatic stress and can complicate disability assessments. The report, released Thursday by the Institute of Medicine, a government advisory group that studies health and medical issues, recommends that the Departments of Defense and Veterans Affairs conduct careful studies “to confirm reports of long-term or latent effects of exposure to blasts.” Some 5,500 military personnel have suffered brain injuries from mild to severe. The wounds account for an estimated 22 percent of all casualties in Afghanistan and Iraq — about twice the rate in Vietnam. Experts attribute this increase in part to better on-site medical care and body armor that allows ground troops to survive blasts that would otherwise be deadly. Copyright 2008 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 12314 - Posted: 06.24.2010

Catching a cold sore puts you at risk of Alzheimer's disease, mounting evidence suggests. The herpes virus behind cold sores is a major cause of the protein plaques that accumulate in the brains of people with Alzheimer's, scientists have shown. On the plus side, the latest discovery by the University of Manchester team may mean antiviral drugs used to treat cold sores could also prevent dementia. The findings are published in the Journal of Pathology. Professor Ruth Itzhaki and colleagues found DNA evidence of the herpes simplex virus (HSV) type 1 in 90% of plaques in Alzheimer's disease patients' brains. They had previously shown that HSV1 infection of nerve-type cells in mice leads to deposition of the main component of the plaques - beta amyloid. And that the virus is present in the brains of many elderly people and that in those people with a specific genetic factor, there is a high risk of developing Alzheimer's disease. Taken together, the researchers say the findings strongly implicate the cold sore-causing virus as a root cause of Alzheimer's dementia. Professor Itzhaki said: "We suggest that HSV1 enters the brain in the elderly as their immune systems decline and then establishes a dormant infection from which it is repeatedly activated by events such as stress, immunosuppression, and various infections." In turn, this causes damages the brain cells, which die and then disintegrate, releasing the proteins which develop into amyloid plaques, she said. The researchers now plan to test whether antiviral drugs used to treat cold sores, which block the action of HSV1, might stop the cell damage that leads to Alzheimer's. (C)BBC

Keyword: Alzheimers
Link ID: 12313 - Posted: 12.08.2008

By LISA SANDERS, M.D. The middle-aged man writhed on the gurney in the E.R. His eyes were squeezed shut. Low moans emerged from his parched lips. His sister and brother — the only members of his large Polynesian family who lived here in Portland, Ore. — tried to comfort him, but worry was etched deeply into their faces. Dr. David Peel, the emergency-room doctor at Providence Portland Medical Center, was also worried. This 53-year-old man had a fever and excruciating pain in his back. One leg was weak and he was confused. But the scariest part of all was that the man had been discharged from this hospital just three days earlier after being treated for the exact same thing. Peel quickly reviewed the records of that first weeklong stay in the hospital. The patient, a smoker, had a history of diabetes and high blood pressure. He came in confused and with a fever. During that admission, the medical team thought he had an infection in his brain, an encephalitis. His white-blood-cell count was high, which was consistent with an infection, and his spinal fluid was abnormal, suggesting inflammation. In addition, the amount of sodium in his blood — an essential mineral and one that is tightly regulated by the brain and the kidneys — was dangerously low, a condition known as hyponatremia. Infections can cause low sodium. So can severe vomiting and diarrhea. And both the encephalitis and the hyponatremia can cause confusion. The team put the patient on powerful antibiotics and was replacing the missing sodium. Treat both, the doctors thought, and the confusion should improve. But it didn’t. His fever went down; his sodium went up. But his confusion remained unchanged. He still didn’t know where he was or why he was there. Copyright 2008 The New York Times Company

Keyword: Miscellaneous
Link ID: 12312 - Posted: 06.24.2010

By MOLLY BIRNBAUM I MOVED to New York on a cold February morning in 2006. When I stepped off the train at Penn Station, lugging two suitcases and a good deal of anxiety, I didn’t smell the garbage overflowing in a bin next to the tracks. I didn’t smell the piping hot coffee in the terminal kiosks as I walked toward the stairs that led to the subway. I didn’t smell the homeless man who shared my car on the F train. When I arrived in New York, I could barely smell anything. There was a whiff of garlic here, a breath of laundry detergent there. But most of my sense of smell had vanished six months earlier, when, on a drizzly August morning while jogging near my family’s home in Boston, I had been hit by a Honda Civic and shattered its windshield with the back of my skull. The trauma of the impact had severed my olfactory neurons, which snake delicately behind the forehead en route to the brain. Before the accident, I had been doing prep work in the kitchen of a small bistro in Boston, training to become a chef. My nights were filled with pristine boxes of wild mushrooms, stacks of chocolate bars from Venezuela and carefully constructed plates of quail. I arrived home in the early morning hours smelling of chicken stock and butter. I loved it. Copyright 2008 The New York Times Company

Keyword: Chemical Senses (Smell & Taste); Regeneration
Link ID: 12311 - Posted: 06.24.2010

By MALCOLM RITTER NEW YORK -- Healthy people should have the right to boost their brains with pills, like those prescribed for hyperactive kids or memory-impaired older folks, several scientists contend in a provocative commentary. College students are already illegally taking prescription stimulants like Ritalin to help them study, and demand for such drugs is likely to grow elsewhere, they say. "We should welcome new methods of improving our brain function," and doing it with pills is no more morally objectionable than eating right or getting a good night's sleep, these experts wrote in an opinion piece published online Sunday by the journal Nature. The commentary calls for more research and a variety of steps for managing the risks. As more effective brain-boosting pills are developed, demand for them is likely to grow among middle-aged people who want youthful memory powers and multitasking workers who need to keep track of multiple demands, said one commentary author, brain scientist Martha Farah of the University of Pennsylvania. "Almost everybody is going to want to use it," Farah said. © 2008 The Associated Press

Keyword: Sleep; Drug Abuse
Link ID: 12310 - Posted: 06.24.2010

Heidi Ledford Fresh evidence suggests that melatonin, a hormone that regulates the body's biological clock, is associated with type 2 diabetes. Epidemiological studies have shown that shift workers have an increased risk of developing type 2 diabetes. And patients with type 1 diabetes have sometimes reported higher blood-sugar levels after taking synthetic melatonin, which can be used to ease jet lag or as a sleep aid. Now, two separate studies by researchers based in Europe and the United States have found that variants of a gene called MTNR1B, which produces a receptor protein that binds and responds to melatonin, is linked to an increased chance of developing type 2 diabetes1,2. In 2007, endocrinologist Leif Groop of Lund University in Sweden and his colleagues published a genetic analysis of nearly 3,000 people, half of whom had type 2 diabetes3. Further work indicated that a sequence variation in the MTNR1B gene was associated with increased levels of glucose in the blood under fasting conditions. Although an abnormally high fasting-glucose level is a symptom of diabetes, the study did not find a link between the variant and the disease. But Groop suspected that the study may have been too small to pick up the association. © 2008 Nature Publishing Group

Keyword: Biological Rhythms
Link ID: 12309 - Posted: 06.24.2010

By Brendan Borrell The baby-faced gunman of Mumbai, Azam Amir Kasab, now in the custody of Indian police, is the sole surviving attacker in the three-day rampage that began on the night of November 26 and left more than 170 people dead and scores of others injured. After the attacks, Indian officials immediately began pointing fingers at longtime rival, Pakistan, as the source of the 10 militants—a charge that Pakistan President Asif Ali Zardari disputed last night on CNN. During police interrogations, Kasab himself claimed to hail from the Punjab region of Pakistan and to have trained with the Pakistan-based extremist group, Lashkar-e-Taiba. Of course, Kasab could be making this all up. The only way that interrogators can tap a man's memory is to ask him. But what if the person is unwilling to spill the beans or, at least, the real ones? If only there were only a way to plug a USB cable to the back of Kasab's head and just download the experiences. While such technology may be the stuff of science fiction, Indian government officials have announced they will employ another technique that seems to leap from the pages of a 1940s pulp novel: truth serum. Also known as narcoanalysis, administering psychoactive drugs for interrogation purposes has been around for just under a century, but it has been viewed with skepticism from the start. Indeed, the practice is banned in most democracies, and evidence obtained from such an interrogation would have a hard time making it into an American court. © 1996-2008 Scientific American Inc.

Keyword: Drug Abuse; Stress
Link ID: 12308 - Posted: 06.24.2010

By Melinda Wenner This year 2.25 million Americans will get married—and a million will get divorced. Could birth control be to blame for some of these breakups? Recent research suggests that the contraceptive pill—which prevents women from ovulating by fooling their body into believing it is pregnant—could affect which types of men women desire. Going on or off the pill during a relationship, therefore, may tempt a woman away from her man. It’s all about scent. Hidden in a man’s smell are clues about his major histocompatibility complex (MHC) genes, which play an important role in immune system surveillance. Studies suggest that females prefer the scent of males whose MHC genes differ from their own, a preference that has probably evolved because it helps offspring survive: couples with different MHC genes are less likely to be related to each other than couples with similar genes are, and their children are born with more varied MHC profiles and thus more robust immune systems. A study published in August in the Proceedings of the Royal Society B, however, suggests that women on the pill undergo a shift in preference toward men who share similar MHC genes. The female subjects were more likely to rate these genetically similar men’s scents (via a T-shirt the men had worn for two nights) as pleasant and desirable after they went on the pill as compared with before. Although no one knows why the pill affects attraction, some scientists believe that pregnancy—or in this case, the hormonal changes that mimic pregnancy—draws women toward nurturing relatives. © 1996-2008 Scientific American Inc.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 12307 - Posted: 06.24.2010

By Bruce Bower There may be no single, simple explanation for reports of recovered memories of childhood sexual abuse. Witness the first evidence that people who report such recall display either of two cognitive profiles, one signaling a susceptibility to retrieving false memories and the other a tendency to have forgotten earlier recollections of actual abuse. Members of the first group typically salvage child sex-abuse memories gradually via psychotherapy that includes hypnosis and other suggestive techniques, say psychologist Elke Geraerts of the University of St. Andrews, Scotland, and her colleagues. Those in the second group suddenly recover memories of abuse, due to unexpected reminders of what happened, the researchers assert in the January Psychological Science. The new research is based on the results of memory tests taken by 120 middle-aged volunteers, mostly women. The work reveals that different ways of remembering and forgetting correspond to how people recover memories of child abuse. Spontaneous recall of actual childhood sexual abuse often produces an illusion of not having remembered those events earlier, Geraerts contends. Her team refers to this phenomenon, which hinges on having recalled the same event in different contexts, as the forgot-it-all-along effect. © Society for Science & the Public 2000 - 2008

Keyword: Learning & Memory
Link ID: 12306 - Posted: 06.24.2010

By Jennifer Couzin With a tanking economy and global violence on the rise, there's at least one thing to smile about: A pair of scientists is reporting that happiness can spread through social networks, meaning that friends of the cheery contract the happiness bug themselves. The data behind the new findings come from, of all things, a massive study of cardiovascular disease. In 1948, researchers began collecting health and other information on U.S. adults as part of the Framingham Heart Study. Today, the project has data on more than 14,000 people, and it has helped researchers identify many of the major risk factors behind heart disease and stroke. Because the Framingham leaders, trying to track volunteers over many years, worried about losing contact with them, they asked all subjects to provide the name of a friend who would know how to find them if necessary. Often, those friends were also part of the study. Nicholas Christakis, formerly a hospice physician at Harvard, and James Fowler, a political scientist at the University of California, San Diego, used these data to create a social network of nearly 5000 people. The duo then matched the information with various health data. Last year, they reported that weight loss and weight gain could "spread" through the network, meaning that a guy whose friends were overweight was more likely to pack on the pounds himself (ScienceNOW, 25 July 2007). Christakis and Fowler published a similar finding on smoking earlier this year. © 2008 American Association for the Advancement of Science.

Keyword: Emotions
Link ID: 12305 - Posted: 06.24.2010

By Guest Columnists Placebos are supposed to be nothing. They’re sugar pills, shots of saline, fake creams; they’re given to the comparison group in drug trials so doctors can see whether a new treatment is better than no treatment. But placebos aren’t nothing. Their ingredients may be bogus, but the elicited reactions are real. “The placebo effect is in some way the bane of the pharma industry’s existence because people have this nasty habit of getting better even without a specific drug,” says David Spiegel, a psychiatrist at Stanford University School of Medicine. It all boils down to expectation. If you expect pain to diminish, the brain releases natural painkillers. If you expect pain to get worse, the brain shuts off the processes that provide pain relief. Somehow, anticipation trips the same neural wires as actual treatment does. Scientists are using imaging techniques to probe brains on placebos and watch the placebo effect in real time. Such studies show, for example, that the pleasure chemical dopamine and the brain’s natural painkillers, opioids, work oppositely depending on whether people expect pain to get better or worse. Other research shows that placebos can reduce anxiety. © Society for Science & the Public 2000 - 2008

Keyword: Pain & Touch
Link ID: 12304 - Posted: 06.24.2010