By Cristen Conger A debate is brewing in the bat research community over one of the winged mammal’s senses. No, it has nothing to do with vision. Despite the tiny eyes and nocturnal lifestyle, none of the roughly 1,100 bat species is blind. “All bats can see and all bats are sensitive to changing light levels because this is the main cue that they use to sense when it is (night time) and time to become active,” said Paul Faure, of McMaster University’s Bat Lab. Instead, researchers can’t agree on a certain aspect of the mammal’s sonar sight, called echolocation. To track down prey, avoid predators and find their way home in the dark, most bats depend on echolocation. They broadcast high-pitched sonar signals and listen for the echoes of sound waves bouncing off objects they’re looking for or obstacles in their path. Bats’ brains then process the auditory information within those echoes as visual maps. Scientists know a lot about the finer points of how echolocation works, but they differ on whether that sense evolved before or after bat’s ability to fly. “Some question whether echolocation 60 million years ago would’ve been too sophisticated,” said Brock Fenton, of the University of Western Ontario. The scientists who discovered Onychonycteris finneyi, the oldest known bat fossil (above), concluded that the prehistoric species could fly but that the sonar sense didn't evolve until later. © 2010 Discovery Channel

Keyword: Hearing; Evolution
Link ID: 14076 - Posted: 06.24.2010

By Jeremy Laurence, A blood test to assess the risk of brain damage in vulnerable newborn babies could save lives and prevent disability, scientists say. The test, carried out on blood taken from the umbilical cord immediately after birth, measures its acidity (the pH level). Blood with a low pH (more acid) indicates a lack of oxygen at birth, which is the commonest cause of brain damage, cerebral palsy and death. Current guidelines suggest that measuring the pH level of umbilical cord blood is worthless as a predictor of how the baby will fare, because the association is inconsistent. But doctors based in Birmingham reviewed 51 studies involving almost 500,000 babies and found a low pH in the cord blood was strongly linked with serious outcomes. Based on their findings, published in the British Medical Journal, they call for increased surveillance of babies born with low cord blood pH and for further research to explore the cost effectivenees of doing the test on all babies. In an accompanying editorial, James Neilson, professor of obstetrics and gynaecology at the University of Liverpool, said: "We should aim to reduce the number of babies born with a low cord pH, without increasing unnecessary obstetric intervention." Andy Shennan, professor of obstetrics at St Thomas' Hospital in London welcomed the study into the relationship between low pH and future health. "Lack of oxygen to the baby during labour will result in a low pH in the umbilical cord," he said. "If it is prolonged, irreversible neurological damage can occur, although this is rare." ©independent.co.uk

Keyword: Development of the Brain
Link ID: 14075 - Posted: 06.24.2010

by Leigh Krietsch Boerner Even if a mouse has never seen a cat before, he’ll turn tail when one is nearby. Researchers suspected that the rodents somehow sniff out their would-be assassins, but exactly what they smelled was unclear. Now scientists have isolated the compound, one of a class of urinary proteins that are secreted by cats, snakes, and a variety of other predators. Mice have two different ways to pick up scents: their nose and a specialized organ inside their nose called the vomeronasal organ (VNO), which helps them detect other mouse pheromones. Suspecting that VNO might help the rodents sniff out predators as well, neurobiologist Lisa Stowers of The Scripps Research Institute in San Diego, California, dropped cotton balls laced with either cat saliva, rat urine, or snake skin essence into the cages of both normal and mutant mice with inactive VNOs. The normal mice cowered in the corner, as if a predator were present. Meanwhile, the mutants weren’t afraid at all, even when an anesthetized rat was placed in their cage. “Some of the subjects were so relaxed that they actually curled up and went to sleep next to the rat,” Stowers says. In addition, using dyes that light up when neurons are activated, the team saw neurons associated with VNOs turn on in response to the scents. These mice were inbred in labs for hundreds of generations, none of them having ever seen a predator, Stowers notes. “This isn’t the mouse learning to recognize these cues,” she says, “he’s born with the ability to detect them.” © 2010 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste); Emotions
Link ID: 14074 - Posted: 06.24.2010

By Katherine Harmon Even cobras need to defend themselves sometimes. These venomous snakes keep adversaries at bay by spitting a neurotoxin or other substance into their perceived enemy's eyes, causing severe pain and sometimes blindness. And they are incredibly accurate in hitting their target—even though it is often moving and more than a meter away. But how can a cobra be so adept at adjusting its venom trajectory (usually launched straight from openings in the fangs) to different scenarios, when fang and venom-opening sizes remain the same? "Basic fluid dynamics would lead you to think that the pattern of the fluid should be fixed," Bruce Young, of the Department of Physical Therapy at the University of Massachusetts Lowell and co-author of a new study, said in a prepared statement. To find out, Young and his colleagues headed into the snake-filled labs of Horst Bleckmann at the University of Bonn Institute of Zoology to taunt some cobras. After donning proper protection, Young met his experimental partners: red spitting cobras (Naja pallida), black-necked spitting cobras (Naja nigricollis) and black-and-white spiting cobras (Naja siamensis). "I just put on the goggles and the cobras start spitting all over," Young said. He was also outfitted with accelerometers on his head, and his human colleagues used high-speed video to film cobras spitting and then compared the movements of the two. The results were published online May 14 in The Journal of Experimental Biology. © 2010 Scientific American

Keyword: Neurotoxins; Vision
Link ID: 14073 - Posted: 06.24.2010

by Teresa Shipley I always knew we women had the magic touch. Turns out that now science can prove it. As babies, we're touched a lot by our mothers, and we actually take a lot of risks. When we took our first steps, tasted new things or explored unknown places, our mothers were there to hold our hands, pick us up and dust us off. They made us feel safer and therefore more likely to keep exploring. Two researchers at Columbia University were curious whether the comforted, secure feelings we have as babies would transfer to adults when they were faced with making a risky choice. They designed an experiment where participants were greeted by either a female or male experimenter and then tested to see if they would take financial risks, such as investing money or gambling. It turns out that the type of touch mattered as much as who was giving it. When a female experimenter touched a participant on the back of the shoulder, that person was much more likely to risk money. If she shook their hands or just spoke to them, however, there was no effect. At the end of the experiment, participants filled out surveys that asked how secure they felt. Those who were touched by the woman, especially if it was on the back, said they felt safer and took bigger risks than those who weren't. But those who were touched by the man didn't show any extra feelings of security. © 2010 Discovery Communications, LLC.

Keyword: Pain & Touch; Emotions
Link ID: 14072 - Posted: 06.24.2010

by Jim Giles Studying animal conflicts could help shed light on human wars – that is the hope from a study of the choices that monkeys make when deciding to fight or remain at peace. Competition for resources is often assumed to be a main cause of conflict in both humans and other animals, says Jessica Flack at the Santa Fe Institute in New Mexico, but that might be wrong. "We find that fighting is based on memories of what other individuals did last." Flack and colleagues Simon DeDeo and David Krakauer analysed data from 160 days of field observations of a group of 84 pigtailed macaques at the Yerkes National Primate Research Center in Lawrenceville, Georgia. The team paid particular attention to which animals fought and how long each fight lasted. Instead of explaining the monkey's fighting ways by dreaming up a strategy based, for example, on the reward value of winning a fight for food or a mate, Flack and colleagues decided to look for strategies suggested by the data alone. They made no assumption about the reasons for the monkeys' behaviour and looked only at patterns of behaviour leading up to fights. This allowed them to determine the relative importance of the factors that led up to a fight. They found that the strategy that best explained involvement in a fight was one in which decisions were based on the presence or absence of pairs of other monkeys. This suggests that social dynamics play a central role. © Copyright Reed Business Information Ltd.

Keyword: Aggression
Link ID: 14071 - Posted: 06.24.2010

by Dan Ferber Brain cells thought to underlie our ability to understand one another work just fine in people with autism spectrum disorders (ASD), according to the authors of a controversial new study. Other researchers had proposed that these cells, called mirror neurons, malfunction in people with ASD, disrupting their ability to understand what someone else is experiencing. If the results hold up, researchers will need another way to explain the social deficits that characterize the disorder. First identified in monkeys, mirror neurons fire when an animal performs particular movements but also when it sees another monkey or a person perform the same movement. Such neurons allow monkeys—and presumably humans—to learn actions by imitating others, and, some researchers believe, to understand other people and empathize with them. People on the autism spectrum struggle to understand what’s happening in other people’s minds, which makes it hard for them to connect socially. Some neuroscientists had proposed that mirror neuron deficits were at the root of their social problems. Several groups had found evidence supporting the mirror neuron hypothesis; for example, neuroscientist Marco Iacoboni of the University of California, Los Angeles, and colleagues reported in 2005 that children with ASD show reduced mirror neuron activity compared with healthy controls when they watch and imitate others making faces. But neuroscientists Ilan Dinstein and David Heeger of New York University and their colleagues considered the previous results in humans inconsistent and inconclusive and designed what they considered “a more in-depth test,” Dinstein says. © 2010 American Association for the Advancement of Science.

Keyword: Autism
Link ID: 14070 - Posted: 06.24.2010

by Gretchen Vogel If you’re reading this at night, beware: You may be affecting your body’s internal clock. Humans, like other animals, rely on light cues to set their body's daily cycle of activity, or circadian rhythm. Now a new study shows that some wavelengths of light, such as those from computer screens, have an unexpectedly strong influence on these rhythms, keeping us awake, for example, when we should be sleeping. In mammals, a well-tuned system of light-sensing cells regulates the area of the brain that controls circadian rhythms, including those governing alertness and hunger. In diurnal animals, for example, light suppresses the production of the hormone melatonin, which is released during the night and promotes sleep. Researchers once thought that the eye’s rod and cone cells, which allow us to see, were responsible for detecting these light cues. But in some blind mice and blind people, circadian rhythms respond normally to changes in light exposure. Scientists now suspect that neurons in the retina that contain melanopsin, a pigment that is sensitive to short-wavelength blue light, drive circadian signals; these cells are still functional in blind people whose body clocks respond to light and dark signals. As a result, some researchers have recommended blue-light therapy for seasonal affective disorder, a type of depression triggered by winter’s short days. Others have developed blue light-blocking goggles to help insomniacs sleep better. But a new study of the specific effects of blue and green light suggests that the real story is more complicated. Neuroscientist Steven Lockley of Brigham and Women’s Hospital in Boston and his colleagues studied how exposure to different levels of light affected the sleep of healthy human volunteers, too. © 2010 American Association for the Advancement of Science

Keyword: Biological Rhythms; Vision
Link ID: 14069 - Posted: 06.24.2010

by Wendy Zukerman Having trouble picking out the guilty party? A brain scan won't help. Jesse Rissman and his team at Stanford University in California have found that monitoring brain activity of witnesses reveals no more than what they say they remember. The study comes amid controversy over whether to admit functional MRI scans as evidence in US courts. Last week, an attorney in New York City attempted to use a brain scan to demonstrate the truthfulness of a witness in an employment case, but failed on a separate legal technicality. And this week, a judge in a federal case in Tennessee was due to decide whether to admit fMRI evidence in a fraud case; if successful, this would be the first time a court anywhere in the world accepted this type of scan. The Stanford team asked 16 volunteers to view 200 mugshots. An hour later, they were again shown pictures of faces, some of which they had seen before and others that were new. The researchers recorded fMRI scans of the volunteers' brains as they reported which faces they recognised. While the brain scans matched the volunteers' decisions on whether the faces were familiar, they could not predict if the recollection was accurate. The team also don't know how easily a witness could cheat the system: remembering a recent event or fabricating a lie may look the same to the scanner. Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1001028107 © Copyright Reed Business Information Ltd.

Keyword: Brain imaging; Learning & Memory
Link ID: 14068 - Posted: 06.24.2010

Sickle cell disease may affect brain function in adults who have few or mild complications of the inherited blood disease, according to results of the first study to examine cognitive functioning in adults with sickle cell disease. The multicenter study, funded by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, compared brain function scores and imaging tests in adult patients with few sickle cell complications with results in similar adults who did not have the blood disease. Researchers report that the brain function scores in sickle cell patients were, on average, in the normal range. However, twice as many patients as healthy adults (33 percent versus 15 percent) scored below normal levels. Those who were more likely to score lower were older and had the lowest levels of hemoglobin, the protein in red blood cells that carries oxygen in the blood, compared to sickle cell participants who scored higher. Findings from brain magnetic resonance imaging scans did not explain differences in scores. Researchers at 12 sites within the NHLBI-supported Comprehensive Sickle Cell Centers conducted the study. Their results are published in the May 12 issue of the Journal of the American Medical Association. An editorial accompanies the article. "This study suggests that some adult patients who have sickle cell disease may develop cognitive problems, such as having difficulty organizing their thoughts, making decisions, or learning, even if they do not have severe complications such as stroke related to sickle cell disease," said NHLBI Acting Director Susan B. Shurin, M.D."Such challenges can tremendously affect a patient’s quality of life, and we need to address these concerns as part of an overall approach to effectively managing sickle cell disease.

Keyword: Genes & Behavior
Link ID: 14067 - Posted: 06.24.2010

By Michelle Roberts Brain scans could be useful as lie detectors to show if a witness lies when identifying a suspect in a crime investigation, US researchers believe. Scientists at Stanford University were able to tell when a person recognised a mug shot by reading their brain waves. Functional magnetic resonance imaging (fMRI) revealed tell-tale brain activity during the memory recall task, Proceedings journal reports. But experts warn the technology is not foolproof and can give false results. And such false positives could have serious legal consequences, say Dr Jesse Rissman and his team, who conducted the research. In their trial, they asked 16 volunteers to study hundreds of faces in an images database. Next, each was shown a series of pictures that included some of the faces they had just seen and some that were new. The researchers asked the volunteers to say which of the mug shots they recognised, while rigged up to the brain-scanning fMRI device. Using computer software to analyse the brain scan data, the researchers were able to recognise distinct patterns that appeared to reflect what the individual was thinking. Specifically, from the scans alone, they were able to tell if the volunteers recognised the faces as old or new and whether this recognition was accompanied by recollection. But the technique was not perfect. It was unable to reliably distinguish between subjects who accurately reported recognising a face and those who mistakenly claimed to recognise a previously unseen face. Lead researcher Dr Jesse Rissman explained: "It was only as good as a person's memory and their memory may or may not be accurate." (C)BBC

Keyword: Stress; Brain imaging
Link ID: 14066 - Posted: 05.11.2010

By PERRI KLASS, M.D. The 8-year-old boy already had hearing aids when I met him, back in the 1990s. He had been born before newborns were routinely screened for hearing problems, so the diagnosis had not taken place until he was a slow-to-talk toddler. An extensive trail of subspecialists had evaluated him after that first test showed severe hearing loss in both ears. A geneticist, a developmentalist, a kidney specialist — no one could find anything wrong. He was a healthy, cheerful child who couldn’t hear very well. Nowadays, 97 percent of babies born in this country have their hearing screened in the newborn nursery. (More in a minute about the clever technologies that make this possible.) That means essential follow-up testing and treatment can begin very early indeed. But the key term is “follow-up.” As many as 46 percent of children who failed the newborn screening test in 2007 did not have documented repeat testing and treatment, said Marcus Gaffney, a health scientist with the Early Hearing Detection and Intervention program at the Centers for Disease Control and Prevention. “Screening a child doesn’t do a lot of good,” Mr. Gaffney told me, “if you don’t take the appropriate follow-up.” Before newborn screening changed the picture in the late 1990s, the average age for diagnosing hearing loss was about 2 ½. And the testing was usually done only because the child’s speech was slow to develop. In children with relatively mild hearing loss, or loss in only one ear, it sometimes took even longer. Copyright 2010 The New York Times Company

Keyword: Hearing; Development of the Brain
Link ID: 14065 - Posted: 06.24.2010

By Katherine Harmon Schizophrenia involves some of the same genetic variations as autism and attention deficit disorders, a new whole-genome analysis study has confirmed. Schizophrenia, which affects about 1.5 percent of the U.S. population, can result in a variety of symptoms that include disrupted thinking, hallucinations, delusions and abnormal speech. The disease is thought to have genetic links but usually does not manifest itself until adolescence or early adulthood. In an effort to assess some of the common genetic variations that might underpin this fairly common but thorny mental illness, researchers sequenced DNA from 1,735 adults with schizophrenia and 3,485 healthy adults. Across the patients that had the disease, the researchers found many frequent variations related to copying or deleting genes, known as copy-number variations. And among the genes that were more likely affected by these changes in schizophrenic individuals were CACNA1B and DOC2A, which help make proteins for calcium signals that regulate neurotransmitters in the brain. Two other more common variations, in RET and RIT2, would likely impact brain development. "These genes affect synaptic function, so deletions or duplications in those genes may alter how brain circuits are formed," Hakon Hakonarson, director of the Center for Applied Genomics at The Children's Hospital of Philadelphia and coauthor of the new study, said in a prepared statement. © 2010 Scientific American,

Keyword: Schizophrenia; Genes & Behavior
Link ID: 14064 - Posted: 06.24.2010

By Emily Anthes Addiction has long been considered a man’s disease. Men are far more likely to use illicit substances, and partly for that reason, research on addiction for decades included only male users. Thus, far more is known about drug dependence in men than in women, and treatment programs and centers have been based on the needs of men. But there are signs that the gender gap is closing, as drug and alcohol use have become more socially acceptable for girls and women. Indeed, drinking and alcohol dependence have grown increasingly prevalent among women in recent decades, but not among men, reported psychiatrist Richard A. Grucza of Washington University in St. Louis in a 2008 study. And in a reversal of past trends, teenage girls are now trying marijuana, alcohol and cigarettes at higher rates than boys are, according to recent results from the National Survey on Drug Use and Health. Meanwhile the survey demonstrated that overall illegal drug use among both girls and women rose from 5.8 to 6.3 percent between 2007 and 2008 as the rate for boys and men dipped from 10.4 to 9.9 percent. What is more, a growing literature on female addicts shows that they are not much like their male counterparts. Women may be uniquely vulnerable to substance abuse and its effects, because female sex hormones affect the brain’s reward circuitry, influencing women’s response to drugs. The studies point to new drug treatments for addiction as well as practical tips for women who want to quit using. © 2010 Scientific American,

Keyword: Drug Abuse; Hormones & Behavior
Link ID: 14063 - Posted: 06.24.2010

Premature babies feel pain more acutely than healthy newborns largely due to the invasive hospital treatments they receive, experts believe. Tests at University College London suggest procedures like tube feeding, injections and blood tests make pre-term infants more sensitive to pain. The researchers say better pain relief should be given to premature babies in intensive care. Their study is published in the journal NeuroImage. The UCL team carrying out the study measured the brain activity of babies with an electroencephalogram (EEG) while they underwent routine heel lancing to draw blood samples. Stronger brain activity was seen for premature infants who had been in hospital for at least 40 days, compared to healthy babies of the same age. This suggests that the premature group are more sensitive to pain. When both groups of babies were gently touched on the heel there was no difference in brain activity, however, suggesting that the sensitisation of preterm babies is specific to pain rather than touch. This, say the researchers, implies that premature babies can benefit from a mother's touch - being held or cuddled - in the same way as normal infants. The study, which was funded by the Medical Research Council, supports previous studies that reported increased sensitivity to pain in older children who were born prematurely. Dr Rebeccah Slater, lead researcher on the study from University college London, said: "Our study shows that being born prematurely and undergoing intensive care affects pain processing in the infant brain. (C)BBC

Keyword: Pain & Touch; Development of the Brain
Link ID: 14062 - Posted: 05.10.2010

Janelle Weaver Humans are not the only ones to grimace when they are in pain, scientists have found. Mice show their discomfort in the same way. Decoding animals' facial expressions may allow researchers and veterinarians to monitor spontaneous pain over long timescales. This may also aid the discovery of painkillers, because this type of pain is similar to that experienced by humans. Researchers typically detect pain in mice by eliciting specific reactions. Poking the hind paw, for example, causes a mouse to reflexively withdraw the paw; heating the tail makes it flick. But scientists are not agreed on how to measure unprovoked pain. To analyse facial expressions in mice, geneticist Jeffrey Mogil at McGill University in Montreal, Canada, and his colleagues have adapted a coding system used to measure pain in infants. The work is published today in Nature Methods1. Mogil teamed up with Kenneth Craig, a psychologist who studies human pain at the University of British Columbia in Vancouver. Expert expression-spotters from Craig's lab compared video frames of mice filmed for up to 30 minutes before and after receiving a painful injection of acetic acid. The researchers detected five signs indicative of pain in mice. Three are similar to human responses: the eyes close and the area around them tightens, and the nose and cheeks bulge. Mice also pull back their ears and move their whiskers. © 2010 Nature Publishing Group,

Keyword: Pain & Touch; Animal Rights
Link ID: 14061 - Posted: 06.24.2010

By Jody Bourton Bonobos have been filmed appearing to 'say no' by shaking their heads, report scientists. On a number of occasions, bonobos were filmed using side to side head movements to prevent others from doing something they did not want them to do. In one film a mother is seen shaking her head to stop her infant playing with its food. This may reflect an early precursor to head-shaking behaviour amongst humans in one of our closest relatives. The study has been published in the journal Primates. "In bonobos, our observations are the first reported use of preventive head-shaking," say Ms Christel Schneider from the Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. This would raise the question of whether these gestures reflect a primitive precursor of the human 'no' head-shake Ms Schneider undertook the study with Dr Josep Call of the Max Planck Institute and Dr Katja Liebal from Freie Universität, Berlin, Germany. Ms Schneider recalls how the videos captured at Leipzig Zoo in Germany show a bonobo mother shaking her head in disapproval when her infant plays with some food. "Ulindi, tried to stop her infant, Luiza, from playing with a piece of leek. Since Luiza took no notice despite repeated attempts to stop her, Ulindi finally shakes her head towards the infant," she says. BBC © MMX

Keyword: Language; Evolution
Link ID: 14060 - Posted: 06.24.2010

By Janet Raloff When Lilian Calderón-Garcidueñas recruited children for a study probing the effects of air pollution, Ana was just 7. The trim girl with an above-average IQ of 113 “was bright, very beautiful and clinically healthy,” the physician and toxicologist recalls. But now Ana (not her real name) is 11. And after putting her and 54 other children from a middle-class area of Mexico City through a new battery of medical and cognitive tests, Calderón-Garcidueñas found that something has been ravaging the youngsters’ lungs, hearts — and, especially troubling, their minds. Brain scans and screening for chemical biomarkers in the blood pointed to inflammation affecting all parts of the brain, says Calderón-Garcidueñas, of the National Institute of Pediatrics in Mexico City and the University of Montana in Missoula. On MRI scans, white spots showed up in the prefrontal cortex. In the elderly, she says, such brain lesions tend to denote reduced blood flow and often show up in people who are developing dementias, including Alzheimer’s disease. In autopsies of seemingly healthy Mexico City children who had died in auto accidents or other traumatic events, Calderón-Garcidueñas uncovered brain deposits of amyloid-beta and alpha-synuclein, proteins that serve as hallmarks of Alzheimer’s and Parkinson’s diseases. Several years earlier, she had found similar abnormalities in homeless Mexico City dogs and exaggerated versions of the abnormalities in local 20- to 50-year-olds. © Society for Science & the Public 2000 - 2010

Keyword: Neurotoxins; Development of the Brain
Link ID: 14059 - Posted: 06.24.2010

by Dan Ferber For a father to truly bond with his children, he needs to grow some new gray matter. At least that seems to be the case in mice. A new study shows that when a mouse father nuzzles his pups, he develops new neurons that help him remember—and protect—those offspring later in life. The results suggest that in mice, and perhaps in humans, young babies and dads bond biologically in ways that can last a lifetime. A few years ago, neuroscientist Samuel Weiss of the University of Calgary in Canada discovered that female mice grow new neurons when they smell pheromones from dominant male mice. The neurons appear in two key structures of the brain: the olfactory bulb and the hippocampus, which together coordinate the memory of odors. That helps the females identify and mate with the dominant males, thereby giving their offspring better odds at survival. Weiss wondered if bonding with their pups would cause similar changes in the brains of new mouse fathers, altering their behavior toward their offspring in ways that might give the pups better odds of success in life. To find out, Weiss and one of his graduate students, Gloria Mak, let mouse couples cohabit in a cage, mate, and produce pups. They removed some of the fathers to another cage as soon as the pups were born, let others hang around for a couple of days and nuzzle with mom and baby, and let a third group hang around, watching and sniffing—but not nuzzling—from outside of a mesh tent. Then the researchers removed all of the dads and reunited them with their sons 6 weeks later when they were fully grown. (They avoided testing daughters because father mice tend to mate with them, making the study hard to interpret.) Dads who did not attack their sons and who spent a significant amount of time nuzzling them were seen as recognizing their offspring. © 2010 American Association for the Advancement of Science.

Keyword: Neurogenesis; Sexual Behavior
Link ID: 14058 - Posted: 06.24.2010

By KIRK JOHNSON ASHBURN, Va. — For generations, the prototypical search-and-rescue case in America was Timmy in the well, with Lassie barking insistently to summon help. Lost children and adolescents — from the woods to the mall — generally outnumbered all others. Have a question about how to prevent an elderly relative from wandering away? An expert will answer some readers’ questions today. But last year for the first time, another type of search crossed into first place here in Virginia, marking a profound demographic shift that public safety officials say will increasingly define the future as the nation ages: wandering, confused dementia patients like Freda Machett. Ms. Machett, 60, suffers from a form of dementia that attacks the brain like Alzheimer’s disease and imposes on many of its victims a restless urge to head out the door. Their journeys, shrouded in a fog of confusion and fragmented memory, are often dangerous and not infrequently fatal. About 6 in 10 dementia victims will wander at least once, health care statistics show, and the numbers are growing worldwide, fueled primarily by Alzheimer’s disease, which has no cure and affects about half of all people over 85. “It started with five words — ‘I want to go home’ — even though this is her home,” said Ms. Machett’s husband, John, a retired engineer who now cares for his wife full time near Richmond. She has gone off dozens of times in the four years since receiving her diagnosis, three times requiring a police search. “It’s a cruel disease,” he said. Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 14057 - Posted: 06.24.2010