Symptoms of mental retardation and autism have been reversed for the first time in laboratory mice. US scientists created mice that showed symptoms of Fragile X Syndrome - a leading cause of mental retardation and autism in humans. They then reversed symptoms of the condition by inhibiting the action of an enzyme in the brain. The study, by Massachusetts Institute of Technology, appears in Proceedings of the National Academy of Sciences. Fragile X Syndrome is linked to mutation in a gene carried on the X chromosome called FMR1. It can cause symptoms ranging from mild learning disabilities to severe autism. The researchers, based at MIT's Picower Institute for Learning and Memory, targeted an enzyme called PAK which affects the number, size and shape of connection between brain cells. They found that inhibiting the enzyme stopped mice with Fragile X Syndrome behaving in erratic ways. Prior to treatment they showed signs of hyperactivity, purposeless and repetitive movements. Further analysis showed that not only were structural abnormalities in connections between brain cells righted, proper electrical communication was restored between the cells. In the brain small protrusions called dendritic spines are responsible for communication between cells. People with Fragile X Syndrome have more dendritic spines than usual, but each is longer and thinner, and transmits weaker electric signals. Blocking PAK activity in the lab mice corrected these abnormalities. (C)BBC

Keyword: Autism; Genes & Behavior
Link ID: 10433 - Posted: 06.28.2007

By Melinda Wenner Female timber rattlesnakes tend to be stay-at-home moms while the males wander the streets — sometimes even suburban streets, according to new research. A team of researchers is seeking out these sneaky rattlers, implanting tracking devices inside them and then turning them loose in order to learn more about their behavior. Wayne Drda, a researcher at the Tyson Research Center at Washington University in St. Louis, and his colleagues recently also learned that, contrary to popular belief, timber rattlesnakes are shy and rarely use their rattlers. This is because they are well camouflaged, and rattling gives away their location. They have also found that females and males behave quite differently. While the females stay with their young for up to 10 days after birth, the males prefer to wander around. Most snakes, however, do return to the same sites year after year. Unfortunately for the snakes, their wanderlust — as well as their tendency to pop up in suburban neighborhoods, where families have unknowingly encroached upon their turf — puts them in danger of being killed by fearful residents. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sexual Behavior
Link ID: 10432 - Posted: 06.24.2010

By NATALIE ANGIER Not long ago, my daughter proposed a way she could earn some extra cash beyond her weekly allowance. Would I give her a quarter, she wanted to know, every time she cleaned the cat box? Twenty-five cents to clean the cat box? I squealed with unconcealed joy. Truly we’d hit commensal pay dirt here. She had fiscal motivation, and I could use the olfactory vacation. But then I read a few items about Toxoplasma gondii, the parasitic protozoa that can be lurking in cat scat, and I changed my mind. I told my daughter that she should skip the litter patrol and try cleaning the refrigerator instead. I’m not normally a fluttering, overprotective mother, and I know that the risk of contracting the toxoplasma pathogen or any serious infectious illness from the cat box is tiny. Still, we’re talking parasites here, and parasitism is an evolutionary force to be reckoned with, a source of nearly bottomless cunning and breathtaking bio-inventiveness. Predators want to kill you and eat you right there on the veldt. Parasites, by contrast, want to keep you alive, the better to serve as a parasite paradise, a cozy haven where they can grow at their own pace, suckle on your moist, nourishing tissues, multiply their numbers and finally, one way or another, pass those numbers along. Toxoplasma, it seems, is a member of a particularly insidious genus of parasite, which seek perpetuity by controlling their hapless hosts’ minds. So maybe I’m hyperventilating here, but if any mind in my house is to be monkeyed with, I would really prefer it be mine. Copyright 2007 The New York Times Company

Keyword: Miscellaneous
Link ID: 10431 - Posted: 06.24.2010

By Michael Shermer Imagine that your child’s private school tuition bill of $20,000 is due and the only source you have for paying it is the sale of some of your stock holdings. Fortunately, you got in on the great Google godsend and purchased 100 shares at $200 each, for a total investment of $20,000, and the stock is now at $400 a share. Should you realize your net gain by selling half of your Google stock and paying off your bill? Or should you sell off that Ford stock you purchased ages ago for $40,000 at its current value of $20,000? If you are like most people (myself included), you would sell your Google stock and hang on to your Ford stock in hopes of recovering your losses. This would be the wrong strategy. Why would you sell shares in a company whose stock is on the rise, and hang on to shares in a company whose stock is on the decline? The reason, in a phrase, is “loss aversion,” and the psychology behind it does not fit the model of Homo economicus, that figurative species of human characterized by unbounded rationality in decision making. Homo economicus is extinct, felled by the new sciences of behavioral economics and neuroeconomics, which have demonstrated that we are remarkably irrational creatures. Thousands of experiments in behavioral economics since Daniel Kahneman and Amos Tversky founded the field with their seminal 1979 paper, “Prospect Theory: An Analysis of Decision under Risk,” have demonstrated that most of us are highly loss averse. Specifically, most people will reject the prospect of a 50–50 probability of gaining or losing money, unless the amount to be gained is at least double the amount to be lost. That is, people feel worse about the pain of a loss than they feel better about the pleasure of a gain. Twice as badly, in fact. © 1996-2007 Scientific American, Inc.

Keyword: Emotions
Link ID: 10430 - Posted: 06.24.2010

Louis Buckley Despite their cumbersome appearance, elephants can run. And, researchers have found, they break into that run at surprisingly slow speeds. Elephants typically stroll along at a leisurely 4 kilometres per hour, explains John Hutchinson of the Royal Veterinary College in London. But once they ramp up to just twice this speed they start to use their back legs "like pogo sticks" to drive their bodies forward, bouncing over their relatively stiff, vaulting forelimbs. This unusual gait counts as running, says Hutchinson, whose study on elephant locomotion is published today in the Journal of the Royal Society Interface1. Hutchinson studied the locomotion of five elephants in safari parks in the United Kingdom. Fitted with four motion sensors — two on their backs, two on their feet — the animals plodded, and in some cases dashed, along a 25-30-metre track, enticed by food rewards and the encouragement of their trainers. The fastest speed clocked up during the experiment was a modest 12.6 kilometres per hour, perhaps suggesting the elephants were a little out of shape. Earlier work by Hutchinson's team in Thailand2 showed that more athletic individuals can reach speeds of up to 24 kilometres per hour, and provided some of the first evidence that elephants can indeed run (as opposed to just walking very quickly) — an issue that had previously been much disputed. But in that study they spotted a running gait only at speeds of more than 16 kilometres per hour. ©2007 Nature Publishing Group

Keyword: Miscellaneous
Link ID: 10429 - Posted: 06.24.2010

IT IS a time parents relish: their child's afternoon nap. But it seems that napping may not be such a good idea after all. Preliminary studies suggest that daytime napping in young children may be linked to poorer sleep and mental functioning than in their peers who only sleep at night. The big question is whether napping is the cause of the problem, or the result. John Harsh at the University of Southern Mississippi in Hattiesburg and his colleagues asked the parents of 738 children aged between 2 and 12 about their children's sleeping habits. Children who took long daytime naps fell asleep at night an average of 39 minutes later and slept later at the weekend than those who did not nap. The effect was more pronounced in older children (over a quarter of 10 to 12-year-olds still took afternoon naps). The problem came during the following week, when children had to wake up at set times to get to school or to meet the demands of their parents' work schedules. The napping children continued to stay up later, meaning they spent less time in bed at night than their counterparts. "Napping children not only had a difficult time getting to bed, they had a harder time falling asleep, and they had a harder time getting up in the morning," says study author Alyssa Cairns, who presented the work at the annual meeting of the Associated Professional Sleep Societies in Minneapolis earlier this month. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Development of the Brain
Link ID: 10428 - Posted: 06.24.2010

By Kim Griggs A young New Zealand scientist has managed to create the world's first large transgenic animal model for Huntington's disease, a devastating neurodegenerative disorder. For her PhD, 25-year-old Jessie Jacobsen from the University of Auckland worked out how to inject into sheep the DNA containing the gene that causes Huntington's. From 150 animals bred at a specialist research facility in South Australia, six sheep were born with the Huntington's gene; and now two are being used to breed a flock. Much of what's known about Huntington's disease comes from studies of the brains of patients who've died from the disease, but little is understood about the early stages of the disease. Huntington's disease affects one person in every 10,000 and the disease causes cell death in the brain, ultimately leading to an inability to walk, talk, think or swallow. It is an insidious disease, as for the first 30 or 40 years of a person's life, there can be no outward signs of the disease's progress. So, it is what happens in those early years that Jacobsen - and the project she is part of - aims to understand. The University of Auckland scientists decided to use sheep because their brain structure is remarkably similar to humans. They also live longer than other laboratory animals such as mice. The researchers, however, will not allow the sheep to develop the symptoms of the disease. Rather, they want to look at what is happening in the brain before symptoms occur. "They will develop the toxic protein like humans do, in exactly the same process; and then the cells will die off, hopefully in a similar pattern; and hopefully we'll be able to discover what's going on," says Jacobsen, who was named New Zealand MacDiarmid Young Scientist of the Year this week. (C) BBC

Keyword: Huntingtons
Link ID: 10426 - Posted: 06.26.2007

Kavita Mishra, Chronicle Staff Writer As the oldest kid in his family, Rich Ha says there's no question he's got more brains than his 17-year-old brother. The 19-year-old San Francisco State University student says his brother is "really smart, but if we had to compare the two, I'd say me." Luckily for Ha, experts wouldn't disagree. Settling nearly a century of debate, researchers in Norway have confirmed what many older siblings have thought all along -- they're smarter. Experts have been split about whether birth order in a family affects intelligence. But after conducting the largest study of its kind, Norwegian researcher Petter Kristensen said the debate is over. "We can dismiss the theory that (intelligence based on birth order) is not a true effect, that it is an artifact," he said. Kristensen and his colleagues, reporting in Thursday's online version of the journal Science, also concluded it doesn't matter if you aren't really the first child. If an older sibling dies young and you end up first in the household, you'll be smarter. © 2007 Hearst Communications Inc.

Keyword: Intelligence
Link ID: 10425 - Posted: 06.24.2010

By CORNELIA DEAN In 1950, in a letter to bishops, Pope Pius XII took up the issue of evolution. The Roman Catholic Church does not necessarily object to the study of evolution as far as it relates to physical traits, he wrote in the encyclical, Humani Generis.” But he added, “Catholic faith obliges us to hold that souls are immediately created by God.” Pope John Paul II made much the same point in 1996, in a message to the Pontifical Academy of Sciences, an advisory group to the Vatican. Although he noted that in the intervening years evolution had become “more than a hypothesis,” he added that considering the mind as emerging merely from physical phenomena was “incompatible with the truth about man.” But as evolutionary biologists and cognitive neuroscientists peer ever deeper into the brain, they are discovering more and more genes, brain structures and other physical correlates to feelings like empathy, disgust and joy. That is, they are discovering physical bases for the feelings from which moral sense emerges — not just in people but in other animals as well. The result is perhaps the strongest challenge yet to the worldview summed up by Descartes, the 17th-century philosopher who divided the creatures of the world between humanity and everything else. As biologists turn up evidence that animals can exhibit emotions and patterns of cognition once thought of as strictly human, Descartes’s dictum, “I think, therefore I am,” loses its force. Copyright 2007 The New York Times Company

Keyword: Miscellaneous
Link ID: 10424 - Posted: 06.24.2010

By Will Dunham WASHINGTON (Reuters) - Two studies published on Monday added to the growing evidence that the most popular class of drugs taken to treat depression may contribute to fragile bones in elderly people. The research focused on a class of antidepressant drugs called selective serotonin reuptake inhibitors. Millions of people, including many elderly, take these drugs, known as SSRIs, which include Eli Lilly and Co's Prozac, known generically as fluoxetine. Two teams of researchers found that older men and women taking SSRIs had more bone loss than those not taking the drugs, which account for more than 60 percent of U.S. antidepressant drug prescriptions. A drop in bone mass can lead to osteoporosis and bone fractures. A team led by Dr. Susan Diem of the University of Minnesota tracked 2,722 women, average age 78, including 198 SSRI users. They measured their bone mineral density five years apart. Those taking the antidepressants experienced a density decrease at the hip of 0.82 percent per year, compared to 0.47 percent per year among those not taking them, the study found. © 1996-2007 Scientific American

Keyword: Depression
Link ID: 10423 - Posted: 06.24.2010

Kerri Smith Humans are often thought of as the only truly altruistic species. We help others out — by giving blood, donating to the poor, or committing to recycling — for no immediate payoff, and often at a cost to ourselves. But evidence is gathering that we might not be alone. Felix Warneken and colleagues at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have shown that chimpanzees will do favours for unrelated chimps - even when they do not get rewarded for it. Previous studies have refuted the idea that chimps are so giving. In 2005, anthropologist Joan Silk of the University of California, Los Angeles, found that when she presented chimps with the choice of getting food just for themselves, or for their entire group, they showed no preference for feeding their pals as well1. But other work has shown that chimps can have a non-selfish streak. In a study published in Science last year2, a Leipzig team reported that chimps would help their human keepers retrieve a pen that they had dropped — an action with no direct benefit for the chimp. That study involved chimps helping out human carers whom they were familiar with — and who had on other occasions provided the chimps with food. To get rid of these complications, the Leipzig team replicated the pen-dropping experiment with unfamiliar humans. As they now report in PLoS Biology3, the chimps still chose to help out. ©2007 Nature Publishing Group

Keyword: Evolution
Link ID: 10422 - Posted: 06.24.2010

By Marissa Cevallos You can tell how nimble an animal is without even looking at its legs: Simply check the size of its inner ear. A new study shows that agile animals, such as tree-swinging gibbons or brown bats, have relatively larger ear canals than their lumbering counterparts the sloths or dugongs, a relative of the manatee. The finding may provide an innovative way to check how quick-footed extinct species were. However, critics point out that in this study, agility is in the eye of the beholder. Organs in the inner ear help steady an animal's motion by synching the body's movement to visual stimuli. The inner ear has three fluid-filled semicircular canals, one circling each spatial dimension, that act like little gyroscopes to detect changes in speed in the direction of motion. Fluids in the semicircular canals flow when an animal jerks its head, in the same way water in a bucket will slosh if you're running with it and suddenly stop. Scientists had noticed that some agile animals, such as graceful gibbons, had larger semicircular canals relative to their body sizes than less maneuverable creatures such as sloths. That would make sense because the bigger hoops should be more sensitive to acceleration, and animals that change direction and speed rapidly have jerkier head motions and experience bigger accelerations. But in spite of anecdotal evidence, it wasn't clear that larger canals always belonged to quicker creatures. To test the pattern, paleontologist Alan Walker of Pennsylvania State University in State College and his team surveyed more than 200 mammals. © 2007 American Association for the Advancement of Science

Keyword: Evolution
Link ID: 10421 - Posted: 06.24.2010

Katharine Sanderson Eldest sibblings are, on average, 2.3 IQ points more intelligent than their younger brothers and sisters, says a study of Norweigan kids. And it's not necessarily being born first that makes the difference — it's being raised as the eldest child. It has been proposed for some time that, on average across a population, first-borns are more intelligent than their younger brethren. There are more first-born sons in prominent positions than might be expected, for example. And some studies have shown a link between birth order and intelligence: the later born, the less smart the child. But the reasons behind this trend, and even whether it's real, have been hotly debated. Families with low-intelligence children tend to be large (perhaps a big brood leaves little time for helping with homework), so the observation that sixth-born children aren't very smart, for example, could just be a side effect of this, critics have said. Petter Kristensen, from the University of Oslo, and Tor Bjerkedal from the Norwegian Armed Forces Medical Services in Oslo looked at data gathered from 241,310 Norwegian kids, all aged 18 or 19 years old at the time of intelligence testing. ©2007 Nature Publishing Group

Keyword: Intelligence
Link ID: 10420 - Posted: 06.24.2010

In 2003, ScienCentral interviewed researcher Michael Kaplitt, assistant professor of neurological surgery at New York-Presbyterian/Weill Cornell Medical Center, and co-founder of Neurologix, Inc. Kaplitt and his team had gotten approval for a Phase 1 study to determine the safety of gene therapy in patients with Parkinson's disease and had performed the world's first gene therapy surgery on a patient with the disease. The findings of the completed study are published in the June 23 issue of the British medical journal The Lancet. The video to the right includes excerpts from our 2003 interview with Kaplitt. For more information on the newly published study, read on. The study reported positive results from the first ever gene therapy trial for Parkinson's disease. The clinical trial studied 12 patients, 11 men and one woman, ranging in age from 50 to 67, who had advanced Parkinson's disease. It was a "Phase 1" study, meaning it was designed primarily to test and prove that the therapy is safe. Kaplitt and his team used a harmless virus called an adeno-associated virus (AAV) as a sort of cargo ship for the corrective gene they wanted to deliver to the patient's brains. The virus carrying the gene called "GAD" (glutamic acid decarboxylase) was injected into a part of the brain called the subthalamic nucleus (STN), which usually has abnormally high activity in Parkinson's patients. This heightened activity leads to the loss of muscle control that is a hallmark of Parkinson's. © ScienCentral, 2000-2007

Keyword: Parkinsons
Link ID: 10419 - Posted: 06.24.2010

Patrick Barry For the first time, scientists have selectively ferried a drug across the blood-brain barrier to treat a neurological disease in mice. The new method could eventually make new treatments possible for a wide range of brain disorders, such as Alzheimer's disease. The walls of capillaries that carry blood into the brain control whether molecules larger than a few hundred atoms, such as antibodies and proteins, can pass into the spaces between neurons. This capillary barrier can stymie doctors' efforts to cure neurological diseases because most medicines can't get through. However, some viruses, including rabies, have molecules that trick the barrier into allowing them to pass. Researchers attached a molecule from the rabies virus to a drug and found that the coupled molecules got through the capillary walls and into the brain. A drug delivered in this way kept 80 percent of mice infected with Japanese encephalitis alive for at least 30 days, while all of the experiment's untreated mice died, the scientists report online and in an upcoming Nature. "I think the potential [of this technique] is enormous," says Manjunath Swamy, senior researcher for the group at the Immune Disease Institute at Harvard Medical School in Boston. ©2007 Science Service.

Keyword: Miscellaneous
Link ID: 10418 - Posted: 06.24.2010

Kerri Smith The way that people talk about 'high' and 'low' notes makes it sound as though musical pitch has something to do with physical location. Now it seems there may be a reason for this: the same bit of our brain could control both our understanding of pitch and spatial orientation. The result comes from a study of tone-deaf people — also known as 'amusics' — which shows that they have poorer spatial skills than those who have no problem distinguishing between two musical notes. Amusics are unable to tell whether a particular musical note is higher or lower than another. The condition has puzzled neuroscientists, because the way in which the brains of amusics process auditory information seems to be no different from normal. Researchers from the University of Otago in New Zealand were keen to investigate. David Bilkey and his student Katie Douglas (who, as a member of the New Zealand Youth Choir, is particularly interested in how the brain processes music) had noticed that music is often described using spatial references, such as 'high' and 'low' notes — with higher notes literally sitting higher on a stave. The same is true in many different languages. So they decided to test the spatial skills of amusic people. ©2007 Nature Publishing Group

Keyword: Hearing
Link ID: 10417 - Posted: 06.24.2010

Boys with autism and autism spectrum disorder had higher levels of hormones involved with growth in comparison to boys who do not have autism, reported researchers from the National Institutes of Health, the Centers for Disease Control and Prevention, the Cincinnati Children’s Hospital and the University Of Cincinnati College Of Medicine. The researchers believe that the higher hormone levels might explain the greater head circumference seen in many children with autism. Earlier studies had reported that many children with autism have very rapid head growth in early life, leading to a proportionately larger head circumference than children who do not have autism. The researchers found that, in addition to a larger head circumference, the boys with autism and autism spectrum disorder who took part in the current study were heavier than boys without these conditions. “The study authors have uncovered a promising new lead in the quest to understand autism,” said Duane Alexander, M.D., Director of the National Institute of Child Health and Human Development, the NIH institute that funded the study. “Future research will determine whether the higher hormone levels the researchers observed are related to abnormal head growth as well as to other features of autism.” Autism is a complex developmental disorder that includes problems with social interaction and communication. The term autism spectrum disorder (ASD) refers to individuals who have a less severe form of autism.

Keyword: Autism; Hormones & Behavior
Link ID: 10416 - Posted: 06.24.2010

Hiroko Tabuchi, Associated Press — Forget the clicker: A new technology in Japan could let you control electronic devices without lifting a finger simply by reading brain activity. The "brain-machine interface" developed by Hitachi Inc. analyzes slight changes in the brain's blood flow and translates brain motion into electric signals. A cap connects by optical fibers to a mapping device, which links, in turn, to a toy train set via a control computer and motor during one recent demonstration at Hitachi's Advanced Research Laboratory in Hatoyama, just outside Tokyo. "Take a deep breath and relax," said Kei Utsugi, a researcher, while demonstrating the device on Wednesday. At his prompting, a reporter did simple calculations in her head, and the train sprang forward — apparently indicating activity in the brain's frontal cortex, which handles problem solving. Activating that region of the brain — by doing sums or singing a song — is what makes the train run, according to Utsugi. When one stops the calculations, the train stops, too. Underlying Hitachi's brain-machine interface is a technology called optical topography, which sends a small amount of infrared light through the brain's surface to map out changes in blood flow. © 2007 Discovery Communications

Keyword: Brain imaging
Link ID: 10414 - Posted: 06.24.2010

A twin brother can reduce his female twin's chances of having children, say scientists at Sheffield University. Women were 25% less likely to have children if their twin was male the study, in Proceedings of the National Academy of Sciences, concluded. Although other factors could play a part - the women were less likely to marry - the team blamed exposure in the womb to the male hormone testosterone. Experts have agreed testosterone might potentially damage female fertility. They said animal work supported this. But they said more work was needed to look at human mechanisms. Both testosterone and the female hormone oestrogen can cross the womb. A female twin foetus is therefore exposed to a brother's testosterone and a male twin foetus to a sister's oestrogen. However, male and female foetuses have similar oestrogen levels, so a female is more likely to be affected, according to Dr Virpi Lummaa's team. Experts already know certain characteristics, including facial features, can be changed by exposure to sex hormones from opposite sex foetuses. To investigate the effect testosterone might have on fertility, the researchers looked back at Finnish medical records spanning 1734 to 1888. They chose this preindustrial population because they argue fertility data on modern Western societies would be skewed by advanced healthcare and assisted conception treatments, such as IVF. (C)BBC

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 10413 - Posted: 06.18.2007

By TINA ROSENBERG Ronald McIver is a prisoner in a medium-security federal compound in Butner, N.C. He is 63 years old, of medium height and overweight, with a white Santa Claus beard, white hair and a calm, direct and intelligent manner. He is serving 30 years for drug trafficking, and so will likely live there the rest of his life. McIver (pronounced mi-KEE-ver) has not been convicted of drug trafficking in the classic sense. He is a doctor who for years treated patients suffering from chronic pain. At the Pain Therapy Center, his small storefront office not far from Main Street in Greenwood, S.C., he cracked backs, gave trigger-point injections and put patients through physical therapy. He administered ultrasound and gravity-inversion therapy and devised exercise regimens. And he wrote prescriptions for high doses of opioid drugs like OxyContin. McIver was a particularly aggressive pain doctor. Pain can be measured only by how patients say they feel: on a scale from 0 to 10, a report of 0 signifies the absence of pain; 10 is unbearable pain. Many pain doctors will try to reduce a patient’s pain to the level of 5. McIver tried for a 2. He prescribed more, and sooner, than most doctors. Some of his patients sold their pills. Some abused them. One man, Larry Shealy, died with high doses of opioids that McIver had prescribed him in his bloodstream. In April 2005, McIver was convicted in federal court of one count of conspiracy to distribute controlled substances and eight counts of distribution. (He was also acquitted of six counts of distribution.) The jury also found that Shealy was killed by the drugs McIver prescribed. McIver is serving concurrent sentences of 20 years for distribution and 30 years for dispensing drugs that resulted in Shealy’s death. His appeals to the U.S. Court of Appeals for the Fourth Circuit and the Supreme Court were rejected. Copyright 2007 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 10412 - Posted: 06.24.2010