"Crunch time" in our lives may mean no "break time." While some people feel like they don't have time between meetings, appointments, and chores throughout the day, researchers at the Massachusetts Institute of Technology say regular breaks are key to forming memories. David Foster and his colleagues say that when rats take a break while exploring an unfamiliar area, their brains instantly replay the information they've just gathered. As the rats run across a track, certain brain cells fire in a specific sequence. Each cell picks a "favorite place" on the track to go off, and a pattern emerges that is replicated every time the rat repeats the route. This "place cell" effect has been documented for more than 30 years. These place cells lie in the hippocampus, which plays a key role in memory and navigation. Foster's research focuses on this part of the brain, which when damaged, he says, may leave a patient with memory problems similar to those seen in the popular 2000 movie "Memento." But Foster and his colleagues were surprised to learn that when the rats took a break after running the track, the same exact place cells fired in reverse order. Replaying multiple times, these patterns were sped up, Foster says, almost 20 times faster. © ScienCentral, 2000-2006.

Keyword: Learning & Memory
Link ID: 9054 - Posted: 06.24.2010

Most people who knit or crochet know what their finished product will look like. But you never know what's going to come from Daina Taimina's crochet hook. And that's the point, says her husband, David Henderson, as he holds up a convoluted piece that resembles lettuce, or a human brain -- if lettuce or brains were purple, that is. "It actually looks like a brain," Henderson marvels. "And I had no idea it was going to look like that until Daina did it." The couple, both Cornell University mathematicians, study and teach about the strange world of hyperbolic space, in which everything constantly curves away from itself. In hyperbolic space the most basic shapes in regular geometry, like a plain old flat plane, are warped into hard to imagine shapes. "If you have something flat, like a flat floor, flat top or flat tabletop, so then that's a zero curvature, nothing is curved," explains Taimina. "If there is a positive curvature, constant positive curvature that's when we get a sphere. And now the question is, if there is a negative constant curvature, what is it? That's a hyperbolic plane. So in some ways we can say it's opposite of a sphere." © ScienCentral, 2000-2006.

Keyword: Development of the Brain
Link ID: 9053 - Posted: 06.24.2010

By Katherine Unger A symmetrical face is often thought a sign of beauty, but symmetry may be a disadvantage when it comes to the brain. "Left-brained" or "right-brained" fish are more adept at handling multiple activities than fish with no hemispheric preference, according to a new study. Their ability to multitask could help explain why vertebrate brains evolved to function asymmetrically. Scientists used to think that only humans had lateralized, or asymmetric, brains. We generally use the left side of our brain to interpret language and the right to appreciate music, for example. Recently, though, researchers have come to believe that lateralized brains are universal among vertebrates. Some think the condition may allow animals to focus on multiple stimuli at once, with each hemisphere dealing with particular cues. Psychologists Marco Dadda and Angelo Bisazza of the University of Padova in Italy decided to test the theory in fish. They first assembled groups of the minnow Girardinus falcatus that had been bred to be either lateralized or nonlateralized. A right-lateralized fish tends to look at a companion out of its left eye and vice versa, because hemispheres process vision on the opposite side of the body. A nonlateralized fish does not favor either eye. When the researchers placed each type of fish in a glass tank and gave it shrimp to eat, they found that lateralized and nonlateralized fish took about the same time to catch 10 shrimp. In addition, both groups caught the shrimp at equal rates on both sides of their bodies, indicating that they weren't favoring either eye while scoping out their prey. © 2006 American Association for the Advancement of Science.

Keyword: Laterality
Link ID: 9052 - Posted: 06.24.2010

Susan Milius On his first trip into Namibia, Chris Faulkes woke up in his tent with a peculiar kink in his back. The ground beneath him had been flat enough when he went to sleep. Yet the next morning, "there was a whopping great lump," he says. A mound of dirt had arisen under Faulkes. He'd inadvertently found—or been found by—Damaraland mole rats, the very creatures he'd come to study. With one of the oddest social systems yet found in mammals, these sub-Saharan rodents spend their lives in networks of underground tunnels that they continually excavate. These mole rats and a better-known species called naked mole rats survive in land that goes months without rain. When rain finally comes, the animals go into a frenzy of digging to expand their tunnels before the ground bakes again. With the mole rats' extreme social system, individuals labor for the sake of the colony. Since the early 1980s, mole rats have been used as models of social organization. The wrinkled, hairless rodent known as the naked mole rat has achieved celebrity status even outside science. In Faulkes' office at Queen Mary College of the University of London stands a cardboard cutout of the Disney-cartoon character of the naked mole rat Rufus. Even the Wall Street Journal has run a page-one story on naked mole rat charms. The subhead read: "What Is Whiskered and Ugly and Has Little Squinty Eyes?—No, Not Your Former Spouse. . . ." Copyright ©2006 Science Service

Keyword: Animal Communication; Sexual Behavior
Link ID: 9051 - Posted: 06.24.2010

Bruce Bower Given all the bad news that science has delivered about brain cells withering and memory waning as the years mount, older people have a right to be cranky. But, instead, the over-50 crowd handles life's rotten realities and finds life's bright side more effectively than whippersnappers do. In no small part, that's because the aging brain makes critical emotional adjustments, a new study indicates. Advancing age heralds a growth in emotional stability accompanied by a neural transition to increased control over negative emotions and greater accessibility of positive emotions, according to a team led by neuroscientist Leanne M. Williams of Westmead (Australia) Hospital. A brain area needed for conscious thought, the medial prefrontal cortex, primarily influences these emotional reactions in older adults, Williams and her colleagues say. In contrast, people under age 50 experience negative emotions more easily than they do positive ones. These younger adults' emotion-related activity centers on the amygdala, a brain structure previously implicated in automatic fear responses. This gradual reorganization of the brain's emotion system may result from older folk responding to accumulating personal experiences by increasingly looking for meaning in life, the researchers propose in the June 14 Journal of Neuroscience. Copyright ©2006 Science Service.

Keyword: Emotions; Alzheimers
Link ID: 9050 - Posted: 06.24.2010

By Michael Purdy -- An epilepsy drug that has been on the market for decades can ease the symptoms of adult sufferers with a genetic disorder that seriously weakens muscles. Scientists at Washington University School of Medicine in St. Louis retrospectively reviewed results from off-label use of the drug valproate to treat seven adult spinal muscular atrophy (SMA) patients. Clinicians offered the drug to patients on the basis of research conducted elsewhere that showed the drug increased levels of a key protein in cell cultures. "The treatment has been fairly successful," says lead author Chris Weihl, M.D., Ph.D., a postdoctoral fellow in neurology. "The drug appeared to be well-tolerated and increased the strength of the patients who took it." The study, now available online, will appear in the August 8 issue of Neurology. Weihl notes that a larger, prospective trial is needed to firmly establish valproate as a treatment of choice for sufferers of this type of SMA. Such trials are already underway elsewhere in pediatric patients who suffer from a different type of SMA that begins earlier in life. Weihl and his colleagues are concerned that valproate may not work as well in those patients. They wanted to make sure that researchers did not discard the possibility that valproate could help older sufferers even if the trials in pediatric patients went poorly.

Keyword: Movement Disorders; Epilepsy
Link ID: 9049 - Posted: 06.24.2006

Howard Hughes Medical Institute researchers have discovered that neurons in the brains of mice sprout robust new connections when the animals are adjusting to new experiences. The new connections alter the circuitry of the brain by changing communication between neurons. The researchers said their findings aid understanding of how procedural learning induces long-term rewiring of the brain. This type of learning is used in mastering skills such as riding a bicycle or typing on a computer. Howard Hughes Medical Institute (HHMI) investigator Karel Svoboda and his colleagues reported their findings in the June 22, 2006, issue of the journal Nature. Other co-authors of the paper included Anthony Holtmaat and Linda Wilbrecht in Svoboda's laboratory at Cold Spring Harbor Laboratory; and Graham Knott and Egbert Welker at the University of Lausanne in Switzerland. Svoboda is one of a handful of researchers in the world who are pioneering the development of new tools and techniques that permit scientists to observe the brain as it rewires over a period of weeks or months. This summer Svoboda will move to HHMI's Janelia Farm Research Campus where he will pursue neurobiology studies and projects in optics and microscopy. In the studies reported in Nature, the researchers used mice that were genetically altered to produce a green fluorescent protein in specific neurons in the neocortex, which is a region of the brain that is known to adapt to new experiences. © 2006 Howard Hughes Medical Institute.

Keyword: Learning & Memory
Link ID: 9048 - Posted: 06.24.2010

By SUSAN SAULNY NEW ORLEANS, — Sgt. Ben Glaudi, the commander of the Police Department's Mobile Crisis Unit here, spends much of each workday on this city's flood-ravaged streets trying to persuade people not to kill themselves. Last Tuesday in the French Quarter, Sergeant Glaudi's small staff was challenged by a man who strode straight into the roaring currents of the Mississippi River, hoping to drown. As the water threatened to suck him under, the man used the last of his strength to fight the rescuers, refusing to be saved. "He said he'd lost everything and didn't want to live anymore," Sergeant Glaudi said. The man was counseled by the crisis unit after being pulled from the river against his will. Others have not been so lucky. "These things come at me fast and furious," Sergeant Glaudi said. "People are just not able to handle the situation here." New Orleans is experiencing what appears to be a near epidemic of depression and post-traumatic stress disorders, one that mental health experts say is of an intensity rarely seen in this country. It is contributing to a suicide rate that state and local officials describe as close to triple what it was before Hurricane Katrina struck and the levees broke 10 months ago. Copyright 2006 The New York Times Company

Keyword: Depression
Link ID: 9047 - Posted: 06.24.2010

By David Brown Heart surgery can help bring on depression, and depression can worsen heart disease. But the relationship between the two conditions is complicated, murky and indirect, according to experts and numerous research studies. The issue arose with the revelation that publisher and former diplomat Philip Merrill had apparently committed suicide while sailing alone on the Chesapeake Bay this month. It had been assumed that he had drowned after falling overboard. When his body was found Monday with a gunshot wound in the head, Merrill's family noted in a statement that he had undergone "significant heart surgery over a year ago" and was taking "several medications" for his heart. "Over the past four weeks," the statement said, "we observed that his spirit had dimmed. We spoke to him and consulted his physician about it. He was fatigued and unmotivated, a clear departure from his lifelong optimistic outlook and irrepressible spirit." Details of the 72-year-old's medical history were not available. Studies have found that 10 to 30 percent of people who have heart attacks or heart surgery develop depression afterward. Usually the mood disorder appears immediately after the illness or procedure, although occasionally it comes on months later. © 2006 The Washington Post Company

Keyword: Depression; Stress
Link ID: 9046 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. The long lives that some former cannibals enjoy before succumbing to a brain-wasting disease suggest that many more humans will eventually die of mad cow disease, scientists said Thursday. But several experts in such illnesses, called prion diseases — which are blamed for killing New Guinea cannibals and British eaters of infected beef — disagreed with that frightening implication of the study, which is to be published Friday in The Lancet, a British medical journal. These experts praised the rigorous work the authors of the report did to confirm that kuru, a disease that once decimated highland tribes in New Guinea, can incubate for 50 years in a few genetically protected people. But the experts said they thought that the findings did not prove that there would be future waves of deaths among people who ate beef from prion-infected cows in the 1980's. "That's a provocative conclusion, but I'm not sure it's totally plausible," said Dr. David Westaway, a prion expert at the University of Toronto. Thus far, only about 160 people, mostly in Britain, have died of variant Creutzfeldt-Jakob disease, which humans get from cows that had bovine spongiform encephalopathy, or mad cow disease.

Keyword: Prions
Link ID: 9045 - Posted: 06.24.2010

No one can deny that becoming a dad is a life-changing experience. And despite an increase in sleepless nights and newly acquired diaper-changing duties, most would agree that it's a deeply enriching and positive one. New findings by brain researcher Kelly Lambert, professor and chair of the psychology department at Randolph-Macon College, suggest that fatherhood may change more than just a man's lifestyle – it may actually cause lasting benefits in his brain. Lambert's research on mother rats has provided mounting evidence that motherhood benefits the brain. She found that mom rats do better on learning and memory tests than non-moms, and are also bolder, suggesting that they are protected against the damaging effects of stress. Lambert linked these changes to the flood of hormones that accompany pregnancy and lactation, but as she wrote in Scientific American magazine, even non-mom rats given "foster" pups showed changes in these areas. Lambert got interested in the possibility that the same could be true for rodent dads. Her most recent experiments show that dads actually do outperform bachelors of the same species at locating food and show less stress in new situations, such as when encountering unfamiliar objects. © ScienCentral, 2000-2006.

Keyword: Sexual Behavior
Link ID: 9044 - Posted: 06.24.2010

For the first time, researchers have enticed transplants of embryonic stem cell-derived motor neurons in the spinal cord to connect with muscles and partially restore function in paralyzed animals. The study suggests that similar techniques may be useful for treating such disorders as spinal cord injury, transverse myelitis, amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy. The study was funded in part by the NIH’s National Institute of Neurological Disorders and Stroke (NINDS). The researchers, led by Douglas Kerr, M.D., Ph.D., of The Johns Hopkins University School of Medicine, used a combination of transplanted motor neurons, chemicals capable of overcoming signals that inhibit axon growth, and a nerve growth factor to attract axons to muscles. The report is published in the July 2006 issue of Annals of Neurology.* "This work is a remarkable advance that can help us understand how stem cells might be used to treat injuries and disease and begin to fulfill their great promise. The successful demonstration of functional restoration is proof of the principle and an important step forward. We must remember, however, that we still have a great distance to go," says Elias A. Zerhouni, Director of the National Institutes of Health.

Keyword: Regeneration; Stem Cells
Link ID: 9043 - Posted: 06.24.2010

Helen Pearson Migraine sufferers might soon be able to block an imminent attack using a device that targets the brain with a powerful magnetic field. The technique, called transcranial magnetic stimulation (TMS), triggers activity in the brain's nerve cells and is already being tested as a way to treat depression. Two small clinical trials have now shown that delivering TMS to the brain in the early stages of a migraine seems to halt it in its tracks. Migraines are crippling headaches that affect around 10% of people in the United States. They are sometime preceded by an 'aura', in which a person sees flashing or shimmering light, blind spots or feels tingling. Yousef Mohammad at Ohio State University Medical Center, Columbus, and his colleagues asked 43 patients to come to the hospital's emergency room when they experienced an aura. Half of them received two short blasts of TMS to the back of the head and half received a placebo blast. After two hours, nearly 70% of the patients who received the TMS reported that they had a mild headache or none at all, compared with 48% of those who received the placebo. Most studies of migraine, like this one, tend to show a very strong placebo effect from a dummy treatment. Mohammad reports his results at the American Headache Society (AHS) meeting in Los Angeles today. ©2006 Nature Publishing Group

Keyword: Pain & Touch
Link ID: 9042 - Posted: 06.24.2010

Brain cells can be enticed into forming uniform functioning patterns using a nano-engineering trick. The technique could allow the development of sophisticated biological sensors that use functioning brain cells, the researchers say. This type of device would identify a compound - a deadly nerve agent or poison, for example - by measuring its effect on a functioning network of neurons. A team led by Yael Hanein of Tel Aviv University in Israel used 100-micrometre-wide bundles of nanotubes to coax rat neurons into forming regular patterns on a sheet of quartz. The neurons cannot stick to the quartz surface but do bind to the nanotube dots, in clusters of about between 20 and 100. Once attached, these neuron bundles are just the right distance from one another to stretch out projections called axons and dendrites to make links with other clusters nearby. Electrical activity Axons and dendrites carry electrical signals between neurons. The electrical activity of the neural network can easily be measured because carbon nanotubes conduct electricity and so can function as electrodes. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Robotics
Link ID: 9041 - Posted: 06.24.2010

Howard Hughes Medical Institute researchers have pinpointed defects in a critical cellular pathway that can lead to the death of dopamine-producing nerve cells and ultimately symptoms of Parkinson's disease. They have also used several animal models of the disease to identify a new way to rescue dying neurons. According to the researchers, the findings offer a promising opportunity for developing new drugs to treat the underlying causes of Parkinson's disease and related neurodegenerative disorders. The research team, which included Howard Hughes Medical Institute investigators Susan L. Lindquist and Nancy M. Bonini, published their findings on June 22, 2006, in Science Express, which provides electronic publication of selected Science papers in advance of print. Lindquist is at the Whitehead Institute for Biomedical Research and Bonini is at the University of Pennsylvania. Antony Cooper of the University of Missouri-Kansas City and Aaron Gitler, who is in Lindquist's laboratory, were co-lead authors on the paper. Other co-authors were from Purdue University, the University of Alabama, Medical College of Georgia and New York University. The researchers' began their experiments seeking to clarify the role of the protein alpha-synuclein in Parkinson's disease. It had long been known that abnormalities in alpha-synuclein could cause a lethal buildup of the protein in neurons. Researchers also knew that accumulation of alpha-synuclein caused neurodegeneration in animal models of Parkinson's disease, but little was known about alpha-synuclein's normal cellular function or how it contributed to disease. One major problem facing researchers, Lindquist said, was that alpha-synuclein accumulation causes a range of abnormalities, and it was not possible to sort out which were causes and which were effects in Parkinson's disease pathology. © 2006 Howard Hughes Medical Institute.

Keyword: Parkinsons
Link ID: 9040 - Posted: 06.24.2010

By BENEDICT CAREY One of the most widely used treatments for the eating disorder anorexia nervosa, the antidepressant Prozac, works no better than dummy pills in preventing recurrence in young women who have recovered from it, researchers are reporting today. The study, the most rigorous to date to test the use of medication for anorexia, should alter treatment for an illness that is often devastatingly chronic and that has a higher mortality than any other psychiatric disorder, experts said. Fewer than a third of the study's participants, who also received regular psychotherapy, remained healthy for a year or more, whether they received drug treatment or not, the study found. An estimated 1 percent of Americans, or about three million people, mostly young women, will at some point suffer from the self-starvation and obsessive anxiety about weight that characterize anorexia, and surveys find that about two-thirds of them receive treatment with Prozac or similar antidepressants, which are considered generally interchangeable. Research suggests that the drugs can be useful in helping people recover from bulimia nervosa, an eating disorder involving bingeing and purging that causes less dramatic weight loss than anorexia. But the new findings put to rest hopes from earlier work that these benefits might carry over to anorexia, experts said. Copyright 2006 The New York Times Company

Keyword: Anorexia & Bulimia; Depression
Link ID: 9039 - Posted: 06.15.2006

By AMY HARMON Jason Dallas used to think of his daredevil streak — a love of backcountry skiing, mountain bikes and fast vehicles — as "a personality thing." Jason Dallas of Seattle says he believes he is genetically predisposed toward risky behavior like backcountry skiing and mountain biking. Then he heard that scientists at the Fred Hutchinson Cancer Research Center in Seattle had linked risk-taking behavior in mice to a gene. Those without it pranced unprotected along a steel beam instead of huddling in safety like the other mice. Now Mr. Dallas, a chef in Seattle, is convinced he has a genetic predisposition for risk-taking, a conclusion the researchers say is not unwarranted, since they believe similar variations in human genes can explain why people perceive danger differently. "It's in your blood," Mr. Dallas said. "You hear people say that kind of thing, but now you know it really is." A growing understanding of human genetics is prompting fresh consideration of how much control people have over who they are and how they act. The recent discoveries include genes that seem to influence whether an individual is fat, has a gift for dance or will be addicted to cigarettes. Pronouncements about the power of genes seem to be in the news almost daily, and are changing the way some Americans feel about themselves, their flaws and their talents, as well as the decisions they make. Copyright 2006 The New York Times Company

Keyword: Genes & Behavior
Link ID: 9038 - Posted: 06.24.2010

LA JOLLA, CA - Wiring the developing brain is like creating a topiary garden. Shrubs don't automatically assume the shape of ornamental elephants, and neither do immature nerve cells immediately recognize the "right" target cell. Abundant foliage, either vegetal or neuronal, must first sprout and then be sculpted into an ordered structure. Neurons extend fibers called axons to target cells in an exuberant manner--some branch to the "wrong" cells while others shoot past their target cells. Axon pieces that went astray degenerate, effectively being "pruned" back. Similarly, when axons are forcibly severed or seriously injured by disease in adults, they die and are removed by degeneration. Scientists have speculated that the same molecular shears used to trim axon branches in injured adult axons also do so during normal developmental pruning. In a forthcoming issue of Neuron, teams at the Salk Institute for Biological Studies and Stanford University revise that notion and, in doing so, suggest how nerve function could be preserved after injury. The collaboration began when senior co-authors Liqun Luo, PhD., a professor at Stanford University and Howard Hughes Medical Investigator, and Dennis D.M. O'Leary, a professor in the Salk Molecular Neurobiology Laboratory, co-wrote a review on neurodegeneration. Of O'Leary, Luo says, "When they asked me to write this review I found that half these things were started by Dennis." O'Leary adds, "We had a great time writing the review and it hatched the idea to combine our ideas."

Keyword: Apoptosis; Regeneration
Link ID: 9037 - Posted: 06.15.2006

Researchers are working on ways to reduce the need for animal experiments, but new laws may increase the number of experiments needed That ideal world, sadly, is still some way away. People need new drugs and vaccines. They want protection from the toxicity of chemicals. The search for basic scientific answers goes on. Indeed, the European Commission is forging ahead with proposals that will increase the number of animal experiments carried out in the European Union, by requiring toxicity tests on every chemical approved for use within the union's borders in the past 25 years. Already, the commission has identified 140,000 chemicals that have not yet been tested. It wants 30,000 of these to be examined right away, and plans to spend between €4 billion-8 billion ($5 billion-10 billion) doing so. The number of animals used for toxicity testing in Europe will thus, experts reckon, quintuple from just over 1m a year to about 5m, unless they are saved by some dramatic advances in non-animal testing technology. At the moment, roughly 10% of European animal tests are for general toxicity, 35% for basic research, 45% for drugs and vaccines, and the remaining 10% a variety of uses such as diagnosing diseases. Animal experimentation will therefore be around for some time yet. But the hunt for substitutes continues, and last weekend the Middle European Society for Alternative Methods to Animal Testing met in Linz, Austria, to review progress. © The Economist Newspaper Limited 2006

Keyword: Animal Rights
Link ID: 9036 - Posted: 06.24.2010

By Jim Dryden -- A new study suggests the brain is quickly turned on and "tuned in" when a person views erotic images. This brain map shows differences in reactions to erotic and neutral visual materials. Red zones represent the largest differences, suggesting that circuits in the frontal parts of the brain are particularly sensitive to erotic content and the fastest to detect the difference. Researchers at Washington University School of Medicine in St. Louis measured brainwave activity of 264 women as they viewed a series of 55 color slides that contained various scenes from water skiers to snarling dogs to partially-clad couples in sensual poses. What they found may seem like a "no brainer." When study volunteers viewed erotic pictures, their brains produced electrical responses that were stronger than those elicited by other material that was viewed, no matter how pleasant or disturbing the other material may have been. This difference in brainwave response emerged very quickly, suggesting that different neural circuits may be involved in the processing of erotic images. "That surprised us," says first author Andrey P. Anokhin, Ph.D., research assistant professor of psychiatry. "We believed both pleasant and disturbing images would evoke a rapid response, but erotic scenes always elicited the strongest response."

Keyword: Sexual Behavior
Link ID: 9035 - Posted: 06.15.2006