By Tracy Staedter, Discovery News — Bats are one of the few terrestrial animals able to navigate through the air using sound. Now a bionic head that mimics a bat's sensory talent is not only helping scientists understand how the animals maneuver but could also lead to much more advanced sonar-based navigation methods for land-based robots. "There are some niches for using in-air sonar and bats have found one niche," said Herbert Peremans, head of the Active Perception Lab of the University of Antwerp and coordinator for the EU-financed CIRCE (Chiroptera Inspired Robotic Cephaloid) bat head project. In the world of robotics, though, sonar has been largely relegated to underwater vehicles. That's because sound travels much further underwater than light or radio waves and is not limited by the murky darkness of deep water. On land, however, sound waves peter out after traveling only 10 or 15 meters and the results returned by commercially available sonar sensors cannot compare to vision- or laser-based systems. But more than 700 species of bats build their survival success on sonar and Peremans and his colleagues think that if they can find out how, they could apply that knowledge to land-based robots. Copyright © 2005 Discovery Communications Inc.

Keyword: Hearing
Link ID: 7820 - Posted: 06.24.2010

US scientists say they have hard evidence to show that certain emotions can cause flare ups of asthma. The University of Wisconsin-Madison team discovered activity in brain areas linking the two in asthmatics who read emotive words. One brain region has a role in obtaining information about disease symptoms while another processes emotions. Their findings appear in Proceedings of the National Academy of Sciences. Dr Richard Davidson and his team asked six patients with mild asthma to take part in their experiments. Each was shown three different categories of words - asthma-related words such as "wheeze", negative but non-asthma-related words such as "loneliness" and neutral words such as "curtains". At the same time, the volunteers were given known triggers of asthma to inhale, such as ragweed or dust-mite extract. Meanwhile, their brain responses were monitored using functional magnetic resonance imaging. Two brain regions - the anterior cingulate cortex and the insula - showed increased activity when the asthma-related words were heard compared with the other word types. Furthermore, the increased brain activity was linked to body function signals from the inhaled allergens. (C)BBC

Keyword: Emotions; Neuroimmunology
Link ID: 7819 - Posted: 08.30.2005

By Marc Siegel America has its killer bugs, but Americans don't, as a rule, express great concern about them: Pneumonia, which killed 63,000 Americans in 2000, draws little public comment. Until 2003, when the flu deaths of 20 U.S. children early in the season were widely publicized, Americans didn't worry much about influenza either, despite the tens of thousands of deaths attributed to that disease each year. In comparison, relatively minor threats are widely feared. First publicized in 2002, West Nile virus was perceived as a great threat, though it killed only 284 people in the United States. In 2003, when severe acute respiratory syndrome, or SARS, emerged in Asia, there were only 7,000 cases in the world and fewer than 100 in the United States. No one in the United States died of SARS, but a lot of people worried. Many patients called my internal medicine practice in New York convinced that the slightest cough was SARS. People were afraid to sit next to an Asian person or to eat in a Chinese restaurant. The connection between excess worry and increased disease risk is not just hypothetical. Numerous studies have shown a link between ill health and stress reported by patients. Each terror alert, too, triggers a wave of often unjustified fear. Anthrax infected 22 people through the U.S. mail in the fall of 2001, killing five. Yet 30,000 people began taking the powerful antibiotic Cipro, many indiscriminately and without a doctor's prescription. © 2005 The Washington Post Company

Keyword: Stress; Neuroimmunology
Link ID: 7818 - Posted: 06.24.2010

US scientists are developing a "glowing" dye to help spot signs in the brain of early dementia. The dye works by binding to the brain areas damaged in Alzheimer's disease and giving off a fluorescent glow that can be seen with a brain scan. The Massachusetts Institute of Technology team have made a prototype that they hope will soon be ready to use clinically. Their findings appear in the journal Angewandte Chemie. Currently, doctors make a diagnosis of Alzheimer's based on a patient's symptoms, but these normally occur much later when the condition has been present for some time. The only way to say for sure that the cause is actually Alzheimer's is after the patient has died, by doing a post-mortem and looking for the characteristic signs the disease leaves in the brain - deposits or plaques made of the protein amyloid. This makes it difficult for doctors looking for a cure for Alzheimer's because they cannot monitor whether candidate drugs are having a direct effect on disease progression in the brain. This prompted Professor Timothy Swager and his team, along with colleagues from the University of Pittsburgh, to make their prototype. When they tested their dye, called NIAD-4, in living mice they found it was able to bind to and "light up" brain amyloid plaques, similar to those seen in people with Alzheimer's. (C)BBC

Keyword: Alzheimers; Brain imaging
Link ID: 7817 - Posted: 08.30.2005

Berkeley - Though humans may never match the tracking ability of dogs, we apparently have the ability to sniff out and locate odors, according to a new study by scientists from the University of California, Berkeley. Student volunteers presented with odors to one nostril or the other could reliably discern where the odor was coming from, and functional magnetic resonance images of their brains showed that the brain is set up to pay attention to the difference between what the left and right nostrils sense, much the way it can localize sounds by contrasting input from the ears. "It has been very controversial whether humans can do egocentric localization, that is, keep their head motionless and say where the spatial source of an odor is," said study coauthor Noam Sobel, associate professor of psychology at UC Berkeley and a member of the campus's Helen Wills Neuroscience Institute. "It seems that we have this ability and that, with practice, you could become really good at it." In future experiments, UC Berkeley biophysics graduate student Jess Porter and Sobel plan to train volunteers to track odors in the field and test the limits of odor localization in humans. Porter, Sobel and their colleagues reported the results in the August 18 issue of the journal Neuron.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 7816 - Posted: 08.30.2005

Waltham, Mass. – In a new study, Brandeis University researchers conclude that older adults with mild-to-moderate hearing loss may expend so much cognitive energy on hearing accurately that their ability to remember spoken language suffers as a result. The study, published in Current Directions in Psychological Science, showed that even when older adults could hear words well enough to repeat them, their ability to memorize and remember these words was poorer in comparison to other individuals of the same age with good hearing. "There are subtle effects of hearing loss on memory and cognitive function in older adults," said lead author Arthur Wingfield, Nancy Lurie Marks Professor of Neuroscience at the Volen National Center for Complex Systems at Brandeis University. "The effect of expending extra effort comprehending words means there are fewer cognitive resources for higher level comprehension." "This extra effort in the initial stages of speech perception uses processing resources that would otherwise be available for downstream operations, such as encoding the material in memory or performing higher-level comprehension operations," explained co-authors Patricia A. Tun and Sandra L. McCoy.

Keyword: Hearing; Language
Link ID: 7815 - Posted: 06.24.2010

OAK BROOK, Ill.--The amount of blood flowing into the brain may play a larger role in the development of dementia than previously believed, according to a study in the September issue of the journal Radiology. Researchers from Leiden University Medical Center in the Netherlands used magnetic resonance imaging (MRI) to examine the brains of elderly patients with and without dementia related to Alzheimer's or Parkinson's disease. As expected, MR images showed that the patients with late-onset dementia had more brain damage compared with young adults and with seniors who had optimal cognitive function. But researchers found that the late-onset dementia group also had a much lower rate of blood flow to the brain than the other two groups. "Our findings not only support the hypothesis that vascular factors contribute to dementia in the elderly, they are highly suggestive that a diminished cerebral blood flow indeed causes brain damage," said Aart Spilt, M.D., a Leiden radiology resident and lead author of the study. "This gives us a clue to the genesis of dementia." Dementia is a loss of cognitive functions, such as thinking, remembering and reasoning, that interferes with normal activities. Although many conditions can produce these symptoms, Alzheimer's disease is the most common cause of dementia. Some patients with Parkinson's disease also develop dementia.

Keyword: Alzheimers
Link ID: 7814 - Posted: 08.30.2005

WASHINGTON - A new study has found that opiate drugs such as morphine leave animals more vulnerable to stress. This means that stress and opiates are in a vicious cycle: Not only does stress trigger drug use, but in return the drug leaves animals more vulnerable to stress. The study, conducted at the University of New South Wales, helps to explain why people who use opiates such as heroin have very high rates of anxiety problems, including post-traumatic stress disorder, even after they stop using. That emotional fragility can also make them more likely to start using again. The study appears in the current issue of the journal Behavioral Neuroscience, which is published by the American Psychological Association (APA). Understanding how opiate users respond to and cope with stress may lead to better treatment and help prevent relapses. Co-author Gavan McNally, PhD, notes that heroin is the most commonly used illicit opiate, followed perhaps by morphine. In medical settings, pethidine, fentanyl, morphine and codeine are typically used. McNally and his colleagues conducted four experiments with rats, injecting them with either morphine or saline solution every day for 10 days. Then, either one or seven days after the final injection, they gently restrained each rat for 30 minutes as a form of stress. The team then measured the rats' biological responses to the restraint stress. They also studied behaviors that reflect anxiety, checking the rats' levels of social interaction and general activity. The researchers tested anxiety responses for three different dose levels and different durations of exposure (0, 1, 5 or 10 days).

Keyword: Stress; Drug Abuse
Link ID: 7813 - Posted: 08.29.2005

While their friends enjoy the latest hit tunes, people who are tone deaf – in scientific terms, suffering from amusia – are excluded from the fun, unable to tell one note from another. The disorder can be congenital, present from birth, or acquired following injury to the brain. In an article published online August 29, 2005, in the Annals of Neurology (www.interscience.wiley.com/journal/ana), researchers now report the first objective measurement of the brain deficit in congenital amusia. The findings may have implications both for amusia and for speech learning disabilities, according to lead study author Isabelle Peretz, Ph.D., of the University of Montreal. Peretz and collaborators at the University of Helsinki assessed brain cell responses to tones across different brain areas using electroencephalography (EEG). Compared to control subjects, people with congenital amusia show abnormal brain activity in the right half of the brain, consistent with earlier findings by Peretz's group and others. It may be possible to compensate for amusia by training pitch discrimination abilities. "However, it is likely that the intervention will only be effective in a 'plastic' brain, in children. We see no sign of improvement in adults," said Peretz.

Keyword: Hearing
Link ID: 7812 - Posted: 06.24.2010

MADISON -- The mere mention of a stressful word like "wheeze" can activate two brain regions in asthmatics during an attack, and this brain activity may be associated with more severe asthma symptoms, according to a study by University of Wisconsin-Madison researchers and collaborators. The study, which appears in the Proceedings of the National Academy of Sciences (Online, August 29, 2005), reveals a functional link between emotion processing centers in the brain and certain physiological processes relevant to disease. UW-Madison psychology professor Richard Davidson, an expert on emotions; and UW-Madison medicine professor William Busse, an expert on asthma; are senior co-authors on the study. Melissa Rosenkranz, a graduate student at the UW-Madison Laboratory for Affective Neuroscience, is the lead author. "While this study was small, it shows how important specific brain circuits can be in modulating inflammation," says Davidson, director of the affective neuroscience laboratory and the Waisman Laboratory for Functional Brain Imaging and Behavior. "The data suggest potential future targets for the development of drugs and behavioral interventions to control asthma and other stress-responsive disorders."

Keyword: Neuroimmunology; Emotions
Link ID: 7811 - Posted: 08.29.2005

Roxanne Khamsi For years, experts have feared that thousands of people are unknowingly carrying and transmitting the human form of mad cow disease: new-variant Creutzfeldt-Jakob disease (vCJD). Now a blood test could help to ease their worries, or confirm their worst nightmare. Researchers have succeeded in reliably detecting the malformed proteins that cause vCJD in blood samples taken from hamsters. Their test takes only a few days to complete. If the procedure works as well in humans, it could be used to check stocks in blood banks. At the moment there is no such screening process; two of the people who have died of vCJD in Britain are thought to have picked up the disease from transfusions. If improved, the test might also be used to screen animals for the disease before they enter the food chain. The rare disease is thought to be caused by the formation of abnormal proteins in the brain known as prions. These misshapen proteins apparently multiply by changing the conformation of normal proteins that they come into contact with, eventually leading to a fatal neurodegenerative illness. ©2005 Nature Publishing Group

Keyword: Prions
Link ID: 7810 - Posted: 06.24.2010

KILLER whales and chimpanzees both pass on "traditions" to other members of their group, according to two separate studies of feeding behaviour. The findings add to evidence that cultural learning is widespread among animals. One study involved killer whales at Marineland in Niagara Falls in Ontario, Canada. An inventive male devised a brand new way to catch birds, and passed the strategy on to his tank-mates. The 4-year-old orca lures gulls into his tank by spitting regurgitated fish onto the water's surface. He waits below for a gull to grab the fish, then lunges at it with open jaws. "They are in a way setting a trap," says animal behaviourist Michael Noonan of Canisius College in Buffalo, New York, who made the discovery, "They catch three or four gulls this way some days." “The orca lures gulls into his tank by spitting regurgitated fish into the water. He waits for a bird to grab the fish and then lunges”Noonan had never seen the behaviour before, despite three years of observations for separate experiments. But a few months after the enterprising male started doing it, Noonan spied the whale's younger half-brother doing the same thing. Soon the brothers' mothers were enjoying feathered snacks, as were a 6-month-old calf and an older male. Noonan presented the research this month at the US Animal Behavior Society meeting in Snowbird, Utah. Wild dolphins off the west coast of Australia were the first marine mammals in which cultural learning was observed. They apparently learn from group-mates how to use sponges to protect their snouts while scavenging (New Scientist, 11 June, p 12). But the evidence from killer whales is much more conclusive because the process was observed from start to finish. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Evolution
Link ID: 7809 - Posted: 06.24.2010

By Caroline Ryan "Schizophrenia is the price that homo sapiens pay for language." That is the controversial theory of one leading psychiatrist. Professor Tim Crow believes that the difference in the development of the human brain from the primate brain - which allows us to process thought and speech - is linked to why psychotic illnesses occur. The human brain has developed to have a strong regional bias, so each side of the brain performs certain roles - for example, speech is controlled by the left side of the brain. Professor Crow of the mental health charity Sane's Prince of Wales International Centre in Oxford, suggests the division boundaries between certain areas of the brain, particularly those which are concerned with language and thought, are "blurred" in people with psychoses. People with these conditions may hear their inner thoughts as external voices, or believe thoughts have been inserted in their head, suggesting the normal divisions do not exist. The reason for this, he says, is that their brains do not have the bias, or asymmetry, seen in healthy people. Brain asymmetry means that areas control certain things, so the left-hand side controls language. He said: "Asymmetry appears to be less pronounced in people with psychoses." (C)BBC

Keyword: Schizophrenia; Language
Link ID: 7808 - Posted: 08.27.2005

Scientists have identified a chemical that can sneak through the blood-brain barrier to treat tumours. The barrier exists to prevent toxic substances getting into the brain, which makes it hard to deliver drugs. Researchers found enough of the chemical, JV-1-36, could bypass the guard to block tumour growth. The University of Saint Louis study, in Proceedings of the National Academy of Science, suggests the compound may also be useful in treating other cancers. The team carried out tests on mice who had had malignant glioblastomas, the most common form of brain tumour, implanted. They then gave an intravenous injection of JV-1-36, which inhibits the effect of the hypothalamic growth hormone-releasing hormone (GHRH). GHRH's role should be to trigger the hormone that makes children grow, but it has also been found to fuel the growth of cancerous tumours. Receptors for the hormone have been found in other cancer cells including breast, ovary, prostate, pancreas and colon. The researchers found that the P-gp system, which acts as an extra "security guard" at the blood brain barrier and usually keeps anti-cancer drugs out of the brain, blocked some of the JV-1-36, but let much of it pass into the brain. The researchers say the compounds gets into the brain by dissolving into the cell membranes which comprise the blood-brain barrier, and not being picked up by P-gp. They say this appears to be because it is not recognised as being a "foreign" substance. (C)BBC

Keyword: Glia; Hormones & Behavior
Link ID: 7807 - Posted: 08.27.2005

Christen Brownlee By fusing an embryonic stem cell with an adult skin cell, researchers have created cells that retain valuable embryonic characteristics but carry the adult cell's genes. This new method might eventually lead to stem cell lines that match a patient's DNA while avoiding the destruction of human embryos, a process that some people find morally unacceptable. Scientists envision someday using embryolike cells to grow tissues for transplant or transplanting such cells into a patient, where they would grow to replace damaged or diseased tissues. If these cells carried a patient's genetic material, they might sidestep the risk of a destructive immune reaction. Some scientists also predict that cells with embryonic properties could give researchers a new way to study genetic diseases. Cells that carry the DNA from a patient with a genetic disease could differentiate in a petri dish, permitting scientists to observe how disease characteristics develop. Korean scientists recently created the first lines of embryonic stem cells derived from clones made with people's cells. However, the team used more than 100 human eggs, which are difficult to obtain, and created early human embryos, which they destroyed to harvest stem cells (SN: 5/21/05, p. 323: http://www.sciencenews.org/articles/20050521/fob1.asp). Copyright ©2005 Science Service.

Keyword: Stem Cells
Link ID: 7806 - Posted: 06.24.2010

By Shankar Vedantam The brain areas involved in daydreaming, musing and other stream-of-consciousness thoughts appear to be the same regions targeted by Alzheimer's disease, researchers are reporting today in an unusual study that offers new insights into the roots of the deadly illness. The strong correlation between the two suggests there might be a link between the sort of thinking that people regularly do when not involved in purposeful mental activity and the degenerative disease that is characterized by forgetfulness and dementia, said scientists who conducted the federally funded study. Randy Buckner, a neuroscientist at Washington University in St. Louis, said the implications of the finding are far from clear. It is too early to suggest that daydreaming is dangerous, he said, or that avoiding such musings could affect the risk of Alzheimer's disease. Rather, he and others said, the study adds to the evidence that everyday mental and physical activities play an important role in the course of neurological disease. "It suggests an avenue between brain activity patterns and Alzheimer's disease that we just hadn't been thinking about," said Buckner, who led the study. "It is going to take some time to understand the relative potential of this link." © 2005 The Washington Post Company

Keyword: Alzheimers
Link ID: 7805 - Posted: 06.24.2010

BOSTON--Dana-Farber Cancer Institute researchers say they have uncovered a molecular explanation for the episodic attacks of irrational and demented behavior in porphyria, the disease believed to have afflicted "Mad" King George III, the British ruler blamed for the loss of the American colonies in the Revolutionary War. The mental and physical symptoms of porphyria, a rare genetic blood disease which a number of modern researchers believe plagued King George intermittently throughout his tumultuous reign, can be brought on by fasting and exposure to certain drugs, and is successfully treated by feedings of sugar and high-carbohydrate food. A biological explanation for these nutritional effects has been lacking. The Dana-Farber scientists say in a report featured on the cover of the August 26 issue of Cell that the nutritional component of porphyria involves a key master metabolic molecule, PGC-1 alpha, in cells of the liver. The gene that makes PGC-1 alpha was isolated in 1998 in the laboratory of Bruce Spiegelman, PhD, who is senior author of the new report. Postdoctoral fellow Christopher Handschin, PhD, is lead author. "We've explained how porphyria symptoms can occur in episodic attacks triggered by fasting, and why they can be treated by feeding carbohydrates and glucose," says Spiegelman.

Keyword: Miscellaneous
Link ID: 7804 - Posted: 08.26.2005

NEW YORK, NY, – An increasingly common method of heroin detoxification under general anesthesia is ineffective and unsafe, according to a study by psychiatrists at Columbia University Medical Center and the New York State Psychiatric Institute at Columbia. The study, published in the August 24 Journal of the American Medical Association (JAMA), is the first rigorously controlled trial to monitor all of the critical outcomes associated with the procedure, including comfort, treatment retention, abstinence rates and the ability to receive the full and effective dose of naltrexone, a drug that blocks activation on the receptor sites in the brain where the opioids attach. Heroin addiction is notoriously difficult to overcome. The nervous system of heroin users adapts over time to accommodate to chronic exposure to the opioid, and its sudden absence during detoxification results in excruciating withdrawal symptoms, including nausea, diarrhea, abdominal pain, insomnia and irritability. Despite improvements in recent decades, medically supervised heroin withdrawal remains plagued by patient discomfort and high dropout rates. This has led to the growth of ultra-rapid, anesthesia-assisted opioid withdrawal procedures, which have been publicized as a fast, painless way to withdraw from opioids.

Keyword: Drug Abuse
Link ID: 7803 - Posted: 06.24.2010

A study published in the current issue of Psychological Science investigates the controversy about whether bisexual men exist. In terms of behavior and identity, they clearly exist as there are men who have sex with both men and women. Upon measuring genital, as well as, self-reported sexual arousal to male and female stimuli, researchers found that, in general, bisexual men did not have a strong genital arousal to both male and female sexual stimuli. Instead, they had strong genital arousal to one sex or the other, but not to both. Most of the time, bisexual men had a genital arousal pattern similar to that of gay men, with stronger genital arousal to male stimuli. However, a subset of bisexual men had genital arousal patterns similar to those of heterosexual men. In contrast to genital arousal patterns, self-reported sexual arousal of bisexual men was substantial to both sexes. The researchers interpreted their results as a lack of a bisexual arousal pattern. "Rather they [the bisexual men] seem to be interpreting or reporting their arousal patterns differently than other men do," researchers Gerulf Rieger, Meredith L. Chivers, and J. Michael Bailey state.

Keyword: Sexual Behavior
Link ID: 7802 - Posted: 08.26.2005

NEW BRUNSWICK/PISCATAWAY, N.J. -- Rutgers' Bonnie Firestein likens nerve cells to trees -- some are short and bushy with many branches while others are tall with a few branches coming out of one or two main trunks. Different branching patterns correlate with specific disorders and Firestein's quest is to discover how these dissimilar patterns come about and why. A new paper by Firestein and her colleagues at Rutgers, The State University of New Jersey, examines the role of the protein snapin in nerve branch, or dendrite, patterning and its potential as a drug target in therapies aimed at learning and memory disorders. The article will appear in the journal Molecular Biology of the Cell but appeared online today at MBC in Press (www.molbiolcell.org/in_press.shtml). While disorders like autism may arise from a multiplicity of causes, research at the cellular level, such as that of Firestein and her Rutgers team, is creating an important point of entry for early intervention with therapeutic drugs. Dendrites are the input centers of neurons -- where nerve cells receive information that they pass on to another nerve cell or to the brain. When there is an abnormal decrease in dendrite branches, there are fewer sites to receive information and communication may be impeded. Individuals with disorders such as autism and Rett syndrome display not only fewer branches, but also show two quite different dendrite patterns.

Keyword: Autism; Learning & Memory
Link ID: 7801 - Posted: 08.26.2005