(Santa Barbara, Calif.) –– Our biological clock, or circadian rhythm, is upset by travelling across time zones, but very soon the body adjusts to the new day/night cycle. New studies of the computational models of the circadian rhythm of fruit flies show that the internal clock is robust, that is, not easily perturbed. These studies may eventually lead to greater understanding of human jet lag as well as human disease states. Engineers at the University of California, Santa Barbara's new Institute for Collaborative Biotechnologies and the Max Planck Institute (MPI) for Dynamics of Complex Technical Systems, in Magdeburg, Germany have analyzed the mechanism of genetic circuits by which the fruit fly regulates its circadian rhythm. The results are published in the August 30 Proceedings of the National Academies of Science. The mechanism controlling the biological clock generates a complicated dynamic behavior, oscillating back and forth and making it difficult to study, but also making it a good prototypical dynamic cellular system. The circadian rhythm of the fruit fly is a regulatory system that takes its cues from the sun. When the sun rises it affects the light-sensitive neurons of the brain of the fruit fly, setting off reactions of proteins at a certain rate depending on the amount of light. The reactions set the clock. There are key proteins and two key feedback loops involved, making the system a hierarchical control scheme, a design tool often used in engineering.

Keyword: Biological Rhythms
Link ID: 6045 - Posted: 06.24.2010

DALLAS – Mice with specific genetic mutations exhibit behavior similar to human psychosis, report UT Southwestern Medical Center at Dallas researchers, providing further support to the notion of a genetic link to schizophrenia. The researchers genetically engineered mice with a mutation in the gene NPAS3, a mutation in the gene NPAS1 or a mutation in both genes. Both genes encode proteins that switch other genes on and off in brain cells. "These mice display certain deficits that are potentially consistent with schizophrenia," said Dr. Steven McKnight, chairman of biochemistry at UT Southwestern and senior author of the study that will appear in an upcoming issue of the Proceedings of the National Academy of Sciences and is to be posted online this week. "It's too early to tell whether the abnormal behavior we observed in these mutated mice can be directly connected with human disease. On the other hand, we find it intriguing that members of a Canadian family carrying a mutation in the human NPAS3 gene have been reported to suffer from schizophrenia." Normal mice in a pen will climb over each other and interact, but the mice with the genetic mutations fail to socialize in this way. Instead, the mutants dart about wildly, avoiding interaction with their normal siblings.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 6044 - Posted: 06.24.2010

By JANE E. BRODY Sam's parents began to suspect something was not quite right when at age 2, their son still was not walking and he said nothing that made any sense. Laboratory and neurological tests showed no abnormalities. But a genetic test revealed that Sam's cells contained an extra copy of the X chromosome. Instead of having 46 chromosomes, including one copy of each of the sex chromosomes, X and Y, the normal complement for a boy, each of Sam's cells had 47 chromosomes, with two X's and one Y, a genetic abnormality commonly called Klinefelter's syndrome. A doubling of the X chromosome, according to a government study of 40,000 infants in the 1970's, occurs once in every 500 to 1,000 male births, making it one of the most common genetic abnormalities. It is a leading genetic cause of male infertility. Yet nearly two-thirds of boys and men who have Klinefelter's do not know it, and many live out their lives never suspecting that they have an extra chromosome. As Sam's mother noted in an interview, doctors, too, are often in the dark. "None of our doctors had ever heard of it," she said. "We did a lot of research on our own." Copyright 2004 The New York Times Company

Keyword: Development of the Brain
Link ID: 6043 - Posted: 08.31.2004

By BENEDICT CAREY If only that very first bite of asparagus had inspired delight, and the first taste of jelly doughnut caused a stomachache. If children's happiest food memories were baked and not fried, leafy green rather than beefy, think of the difference in what people might eat. Now, think of what it might mean to change those memories - as an adult. Psychologists in California and Washington were studying false memories when they stumbled on a surprisingly easy target for manipulation: foods. In a study accepted for publication in the journal Social Cognition, the researchers describe how they fooled college students into thinking that as children they had become sick when eating certain foods. The students answered questions about their early eating memories. A week later, they were presented with a bogus food history profile that embedded a single falsehood - that they had gotten sick when eating pickles or hard-boiled eggs - among real memories. "This is called the false feedback technique, where you gather data from the subjects and use it to lend credibility to this false profile," said Dr. Elizabeth Loftus, a psychologist at the University of California at Irvine who led the research. Copyright 2004 The New York Times Company

Keyword: Learning & Memory
Link ID: 6042 - Posted: 08.31.2004

Sex hormones influence brain development, establishing differences between male and female brains. The hormones may do this by telling neurons in certain brain regions whether to kill themselves, according to a new study that finds that male and female brains are much more similar than usual in mice missing a cell-suicide gene. During mammalian development, testosterone and its chemical cousins give males more neurons in some brain regions and leave females with more in others. Previous work hinted that testosterone does this by triggering programmed cell death, or apoptosis, in certain regions but repressing it in others. However, other mechanisms--such as rates of cell birth, migration, or maturation--had not been ruled out. To investigate the role of apoptosis, neurobiologist Nancy Forger of the University of Massachusetts, Amherst, and her colleagues examined the brains of mice missing a gene called Bax. Previous studies had found that knocking out Bax eradicates cell death completely. The team counted cells in two forebrain regions that normally differ in male and female mice: the principal nucleus of the bed nucleus of the stria terminalis, where males normally have more neurons, and the anteroventral periventricular nucleus (AVPV), where females have more neurons. Bax deletion completely eliminated these differences, even though hormone levels in the mice were normal, the researchers report this week in the Proceedings of the National Academy of Sciences. Each of these areas must have a different molecular "switch," Forger says, so that testosterone activates apoptosis in the AVPV but represses death in the bed nucleus. Removing Bax didn't eradicate all differences between the sexes, however: Bax-less females, like their genetically normal counterparts, still had a greater proportion of dopamine-releasing neurons in the AVPV than did males. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior; Apoptosis
Link ID: 6041 - Posted: 06.24.2010

For the first time, researchers have shown a biological basis for autism IT MIGHT take only the touch of peach fuzz to make an autistic child howl in pain. The odour of the fruit could be so overpowering that he gags. For reasons that are not well understood, people with autism do not integrate all of their senses in ways that help them understand properly what they are experiencing. By the age of three, the signs of autism—infrequent eye contact, over-sensitivity or under-sensitivity to the environment, difficulty mixing with others—are in full force. There is no cure; intense behavioural therapies serve only to lessen the symptoms. The origins of autism are obscure. But a paper in Brain, a specialist journal, casts some light. A team headed by Marcel Just, of Carnegie Mellon University, and Nancy Minshew, of the University of Pittsburgh, has found evidence of how the brains of people with autism function differently from those without the disorder. Using a brain-scanning technique called functional magnetic-resonance imaging (fMRI), Dr Just, Dr Minshew and their team compared the brain activity of young adults who had “high-functioning” autism (in which an autist's IQ score is normal) with that of non-autistic participants. The experiment was designed to examine two regions of the brain known to be associated with language—Broca's area and Wernicke's area—when the participants were reading. Copyright © The Economist Newspaper Limited 2004. All

Keyword: Autism
Link ID: 6040 - Posted: 06.24.2010

By Sarah Webb Since the 19th century, neuroscientists have speculated that human emotion might be a kind of secondary sensory response: The brain translates sense data (the sight of an oncoming bus) into a physical reaction (elevated heart rate), which then triggers an emotional one (fear that bus is going to hit). Testing the theory directly is not ethically possible, but new, indirect experiments support the link between sensation and emotion. Hugo Critchley of University College London looked for signs that emotional awareness is tied to heartbeat perception in the brain. If physical reactions trigger emotion, he reasoned, people who are highly attuned to bodily processes should also be unusually sensitive. He and his collaborators tested the ability of 17 subjects to perceive whether a series of tones was synchronized with their hearts. The researches also scanned the subjects’ brain activity and later asked them to fill out a questionnaire. Subjects who more accurately judged their heartbeats tended to have greater activity in the right anterior insula, a region deep in the brain. They also reported feeling negative emotions, such as fear or anger, more deeply than the other subjects did. Stefan Wiens of Karolinska Institute in Stockholm, who helped run the study, notes that people who think they are viscerally aware often aren’t, and that those who are often do not realize it. So far, trying to teach people to recognize the timing of their heartbeats has not exactly lead to greater sensitivity. Attempts to learn, Wiens says, have tended to frustrate subjects or make them more anxious. © 2004 The Walt Disney Company.

Keyword: Emotions; Brain imaging
Link ID: 6039 - Posted: 06.24.2010

A cannabis-like substance produced by the brain may dampen delusional or psychotic experiences, rather than trigger them. Heavy cannabis use has been linked to psychosis in the past, leading researchers to look for a connection between the brain's natural cannabinoid system and schizophrenia. Sure enough, when Markus Leweke of the University of Cologne, Germany, and Andrea Giuffrida and Danielle Piomelli of the University of California, Irvine, looked at levels of the natural cannabis-like substance anandamide, they were higher in people with schizophrenia than in healthy controls. The team measured levels of anandamide in the cerebrospinal fluid (CSF) of 47 people suffering their first bout of schizophrenia, but who had not yet taken any drugs for it, and 26 people who had symptoms of psychosis and have a high risk of schizophrenia. Compared with 84 healthy volunteers, levels were six times as high in people with symptoms of psychosis and eight times as high in those with schizophrenia. "This is a massive increase in anandamide levels," Leweke told the National Cannabis and Mental Illness Conference in Melbourne, Australia, last week. And that is just in the CSF. Levels could be a hundred times higher in the synapses, where nerve signalling is taking place, he says. © Copyright Reed Business Information Ltd.

Keyword: Schizophrenia; Drug Abuse
Link ID: 6038 - Posted: 06.24.2010

By ANDREW POLLACK Eyetech Pharmaceuticals' drug to treat the leading cause of blindness in the elderly appeared to move closer to a broad government approval yesterday after an advisory panel to the Food and Drug Administration spoke favorably about it. The advisory panel was not asked to vote on whether the drug, Macugen, should be approved as a treatment for age-related macular degeneration. But committee members ruled unanimously that Eyetech had provided the F.D.A. with enough information to evaluate the drug. The panel members also did not seem to raise any serious new issues that would block approval. "It appears to me very efficacious and safe,'' Jose S. Pulido, a panel member and an ophthalmologist at the Mayo Clinic, said during the meeting, held in Rockville, Md. Copyright 2004 The New York Times Company

Keyword: Vision
Link ID: 6037 - Posted: 08.28.2004

PORTLAND, Ore. – For years, doctors have suggested the best treatment for multiple sclerosis is pregnancy. Now, an Oregon study is delivering solid evidence to support the theory. Researchers at Oregon Health & Science University and the Portland Veterans Affairs Medical Center have uncovered the mechanism by which estrogen, produced in high volumes during pregnancy, boosts the expression and number of regulatory cells that are key to fighting MS and other autoimmune diseases, such as arthritis and diabetes. The study, published in the "Cutting Edge" section of the current issue of The Journal of Immunology, shows the hormone augments a compartment containing T cells known as CD4+CD25+, and a regulatory protein called FoxP3. The cells are important for protecting mice against a model for human MS called experimental autoimmune encephalomyelitis (EAE). Autoimmune disease has been associated with a deficiency of FoxP3, whose expression is a reliable indicator of the regulatory T cells' function and development. "This is the first report that this single, benign compound – estrogen – can increase regulatory cells," said study co-author Halina Offner, Ph.D., professor of neurology, and anesthesiology and peri-operative medicine, OHSU School of Medicine and the Portland VA Medical Center. "When you remove (the CD4+CD25+ cells), animals get autoimmune disease. They're very important to maintaining a healthy state."

Keyword: Multiple Sclerosis; Hormones & Behavior
Link ID: 6036 - Posted: 06.24.2010

Mark Peplow Neuroscientists have created a computer game based on table tennis that people can play using nothing more than the power of their minds. It is hoped that the technology will one day train people to generate neural signals that could control a wheelchair or communication device. Each 'brain pong' player lies in a functional magnetic resonance imaging (fMRI) machine, usually reserved for medical brain scans. After a short period of training, the players are able to make their ping-pong bat move up and down the screen by concentrating on specific thoughts. Sophisticated data analysis software makes the system responsive enough for two players to compete in real time. "It's exciting that for the first time we have two subjects whose brains are interacting like this," says Rainer Goebel, a neuroscientist at Maastricht University in the Netherlands, who described the work on 27 August at the EuroScience Open Forum in Stockholm, Sweden. Other researchers have shown that it is possible to control cursors on a computer screen by detecting electrical signals from the brain. But this is the first two-player game that exploits brain activity. The improved sensitivity of fMRI also makes it much easier to learn to control the bat, says Goebel. ©2004 Nature Publishing Group

Keyword: Robotics
Link ID: 6035 - Posted: 06.24.2010

CHAMPAIGN, Ill. -- Does estrogen help cognition? Many women ponder that question as a quality-of-life issue while deciding on estrogen therapy since it has been linked to potential disease complications. Now, a new study at the University of Illinois at Urbana-Champaign suggests that the stress of any given task at least partially determines if hormones will help the mind. Reporting in the August issue of Behavioral Neuroscience, four researchers show the introduction of a single stressor -- water temperature -- into a water maze prompted opposite responses among female rats with either high or low levels of estrogen and progesterone. "Water temperature totally reversed who did better," said Janice M. Juraska, a professor of psychology and of neuroscience. "Proestrous rats, which have high hormone levels, did better when the water was warm, presumably because they were less stressed. Estrous rats did better when the water was cold, presumably because they are not as prone to get stressed during this time." Proestrous rats are fertile and ready to mate, while estrous rats have low hormone levels and won't mate. For the study -- funded by a grant to Juraska from the National Science Foundation -- 44 female rats were divided into four groups. The two groups of rats in proestrus and the two groups in estrus had to learn the route and swim to a submerged platform in either warm (91 degrees Fahrenheit; 33 Celsius) or cold water (66.2 degrees Fahrenheit; 19 Celsius).

Keyword: Learning & Memory; Hormones & Behavior
Link ID: 6034 - Posted: 08.28.2004

People genuinely enjoy telling others off if they have done something wrong, according to scientists. Researchers from the University of Zurich in Switzerland tested seven pairs of men as they played a game. The game involved money changing hands. If one player failed to play fairly, he tended to be punished by the other. Writing in Science, the researchers said telling someone off activated a part of the brain which is linked to enjoyment and satisfaction. The researchers said it might explain why many people choose to reprimand others if they break the rules or abuse their trust. The men playing the game were unable to see each other. They were each given 10 units of money and told they could increase their winnings if they trusted each other. The first player was given the option of keeping all his money or giving it to his opponent. If he kept his money, he did not make anything extra. But if he gave it all to his opponent, the opponent's winnings would quadruple. The second player would then be asked whether he wanted to keep the money or share it with his opponent. If he failed to share it, the first player would be asked whether or not his opponent should be punished. They were given one minute to make their decision. In six out of the seven cases, they chose to reprimand them. During the time it took them to make their decision, scientists monitored their brain. (C)BBC

Keyword: Emotions
Link ID: 6033 - Posted: 08.27.2004

By GARDINER HARRIS In a settlement that the New York attorney general said would transform the drug industry, GlaxoSmithKline agreed yesterday to post on its Web site the results of all clinical trials involving its drugs. "This settlement is transformational in that it will provide doctors and patients access to the clinical testing data necessary to make informed judgments," the attorney general, Eliot Spitzer, said. While the case involves only GlaxoSmithKline, the British drug maker, Mr. Spitzer predicted that other companies would follow its lead by posting the results of their studies online. Eli Lilly, for example, has said it would create a Web site on which it would list the results of clinical tests of approved drugs. Other companies, including Johnson & Johnson and Merck, have said they support the concept of a public database that would list trial results. Mr. Spitzer filed suit in June against GlaxoSmithKline, contending that it committed fraud by publicizing the results of only one of five trials studying the effect of its antidepressant, Paxil, in children. That single study showed mixed results. The others not only failed to show any benefit for the drug in children but demonstrated that children taking Paxil were more likely to become suicidal than those taking a placebo. Copyright 2004 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 6032 - Posted: 08.27.2004

Two books on the (big) business of the pharmaceutical industry. Reviewed By Shannon Brownlee Every author should be so lucky. While Jerome Kassirer and Marcia Angell were holed up in their offices, typing away, Congress launched an investigation into financial entanglements between industry and the National Institutes of Health. Then Pfizer was hit with nearly half a billion dollars in fines for paying doctors to hype its anti-seizure drug Neurontin for unapproved—and largely unproven—uses. Now, New York state attorney general Eliot Spitzer has accused another drug giant, GlaxoSmithKline, of burying evidence that the antidepressant Paxil can trigger suicide. It's great news for Angell's and Kassirer's book sales, bad news for the rest of us. These stories about the unholy alliance between the pharmaceutical industry, researchers, and doctors may have seemed, to the casual observer, like nothing more than isolated blips. Sad to say—as these surprisingly bare-knuckled books by the last two editors-in-chief at the New England Journal of Medicine make clear—such accounts provide a mere glimpse of the corruption of medical science. In the last two decades, the drug and biotech industries have gained unprecedented leverage over what doctors and patients know—and don't know—about the $200 billion worth of prescription pharmaceuticals consumed by Americans each year. Industry has gained that leverage by funding and, increasingly, controlling medical research. It has also used its deep pockets to effectively buy the loyalty of physicians in private practice and to sway the opinion of thought-leaders in academia. Grasp the full scope of industry influence over medical science and practice, and it's enough to make anybody think twice before filling a prescription. © 2004 The Foundation for National Progress

Keyword: Depression
Link ID: 6031 - Posted: 06.24.2010

A bad night's sleep for a child could mean more, in the long run, than just a cranky kid. As this ScienCentral news video reports, new research suggests that childhood sleep troubles may be a potential marker for alcohol, cigarette and drug problems later in life. Even as first-time parents, Suzanne Hill and Ralph Scibelli knew that babies often wake up during the night, but after the a year or so their son Ethan was only sleeping a few hours at a time, waking up throughout each night. "Ethan did not like to sleep," Scibelli recalls. They tried feeding him more, walking him around their Manhattan neighborhood, playing soothing music and even resorted to letting him cry in hope that he would tire himself out. Nothing worked. "We tried everything." Hill says. "Three and a half, four hours would be the maximum that he would sleep. We just said, 'Ok, well if this is the way he is...'" Fortunately, Ethan outgrew his restless nights. But what if he hadn't? © ScienCentral, 2000- 2004.

Keyword: Sleep; Drug Abuse
Link ID: 6030 - Posted: 06.24.2010

Columbia University Medical Center and Albert Einstein College of Medicine researchers have identified a possible cause of an inherited form of Parkinson's disease, which may be related to more common forms of the disease. The findings are reported in the August 27, 2004 issue of Science. While the cause of most cases of Parkinson's disease is unknown, a few cases are inherited and can be traced to mutations in four different genes, including the alpha-synuclein gene. This is the first study that may pinpoint the mechanism by which the mutant gene initiates a cascade of events that causes this devastating neurological disease. "This discovery could aid in the development of new, targeted treatments to slow or stop the disease progression," said David Sulzer, Ph.D., professor of neurology and psychiatry at Columbia University College of Physicians and Surgeons and senior author of the study. "This is an extension of the genetic research that discovered the mutant alpha-synuclein gene and it is exciting to see how this information can be used to possibly determine the cause of Parkinson's disease."

Keyword: Parkinsons
Link ID: 6029 - Posted: 08.27.2004

Mice “rewired” to receive visual cues in the hearing region of their brains learned to respond to a fear-inducing flashing light as if they had heard it instead of seen it, researchers from MIT’s Picower Center for Learning and Memory report in the Aug. 22 online issue of Nature Neuroscience. This research shows that even the adult brain is far more plastic, or adaptable, than previously believed. If extended to humans, this may mean that in the future, individuals with brain damage from aging, disease or injury may be able to have stimuli from the outside world routed in new ways to major brain structures—even those responsible for emotional responses and learning. This work also sheds light on how emotional responses are learned, illustrating the ability of widely different external stimuli to elicit a common emotion such as fear. The research is the result of a collaboration between the laboratories of Mriganka Sur, the Sherman Fairchild Professor of Neuroscience and head of the MIT Department of Brain and Cognitive Sciences, and Susumu Tonegawa, director of the Picower Center and professor of biology.

Keyword: Development of the Brain; Emotions
Link ID: 6028 - Posted: 06.24.2010

In an effort that may someday lead to the treatment of hearing loss and balance disorders, which currently affect about 28 million Americans, Marine Biological Laboratory (MBL) visiting investigators Jeffrey Corwin and Stefan Heller are working this summer to make large numbers of mouse stem cells "grow" into inner ear sensory hair cells-acoustic receptors that are a critical part of the auditory system. The work is important because, in humans, inner ear sensory hair cells are a precious commodity. Humans are born with only about sixteen thousand of these sound detectors in each ear, which can be easily damaged by age, certain illnesses, exposure to loud sounds, and some medications. Once damaged, the cells do not easily grow back. And with the cell loss comes so-called irreversible hearing loss. The two scientists are collaborating to develop new methods to expand and maintain adult stem cells isolated from the mouse inner ear to establish long-term stable cell lines. This is the first step toward the ultimate goal of creating implantable human hair cells that will grow happily; eventually repairing damaged hearing and restoring balance. © 2004 by The Marine Biological LaboratoryTM

Keyword: Hearing
Link ID: 6027 - Posted: 06.24.2010

Many men dream of having a larger member, and penis envy is at the root of much popular psychology - witness all those unwanted e-mails. But the idea of having a penis so large that it is an encumbrance is horrific. Penis length in humans generally varies from 10-20cm (erect), but there is a tribe in Africa in which the male member is much longer, and its owners tie it into a loose knot while walking. But for these people, it is big, but not quite an encumbrance. Among animals, penises show a startling variation in both size, shape and number. Some flatworms have dozens of penises - essential because, in the competition over mates (which is complex because they are all hermaphrodites), individuals bite off each others' penises at every opportunity. The record for size must go to another hermaphroditic beast, the Corsican slug, whose fully extended member is 60cm long, four times longer than its body. The human equivalent would be an 8m-long penis. Penises are important. Not just because they bring us joy and make us laugh, but because they provide a beautiful example of evolution in action. Competition between males to sire offspring results in the rapid evolution of animal genitalia - both male and female, since they tend to co-evolve. Male genitalia are more obvious because they are often on show, and the diversity in penis design is so remarkable that biologists can often discriminate between otherwise indistinguishable species on this characteristic alone. © 2004 Independent Digital (UK) Ltd

Keyword: Sexual Behavior
Link ID: 6026 - Posted: 06.24.2010