Radar has helped resolve a long-standing controversy about the purpose of a strange dance performed by bees, Nature magazine reports. The famous "waggle" dance contains information about the whereabouts of nectar, just as was originally proposed in the 1960s, scientists now claim. The theory met with scepticism, partly because people did not believe bees could decode such a complex message. But now radar tracking has proved they do follow waggle dance instructions. Bee-keepers have long puzzled over the mysterious little performance, which bees stage for their hive-mates when they return home from a foraging mission. On entering the hive after gathering nectar, a bee will run around in a tight figure of eight dance, waggling its abdomen as it does so. All the other bees gather around, apparently scrutinising the ceremonial manoeuvre. "It is, at first sight, a rather confusing and not very organised movement," said co-author Joe Riley of Rothamsted Research, UK. "But if you watch it carefully you can recognise the very distinct and organised pattern." It wasn't until the 1960s that a plausible explanation for the dance was proposed, by Nobel Prize winning zoologist Karl von Frisch. He suggested that the bees are delivering a complex set of instructions about how to find a rich nectar source. The direction the bees point while performing the dance, Professor von Frisch speculated, indicates the direction of the food source in relation to the Sun; while the intensity of the waggles indicate how far away it is. (C)BBC

Keyword: Animal Communication; Language
Link ID: 7337 - Posted: 05.12.2005

As far back as the American Civil War doctors have documented cases where patients seemed to experience phantom pains in an uninjured arm or leg after suffering an injury to their opposite limb. While working to understand the biological causes of chronic pain, neurologist Anne Louise Oaklander became curious about these types of phantom pain, having heard surprising complaints from some of her patients. "I had a number of patients who mentioned to me that they had symptoms of injury in the opposite limb, as well as in the injured limb," explains Oaklander, MD, director of the Nerve Injury Unit at Massachusetts General Hospital in Boston. Oaklander's research group has shown that the so-called "mirror-image pain" can't be simply explained away by overuse of the uninjured limb, or as psychological. "These seemingly bizarre complaints have contributed to the impression that some chronic pain patients are crazy," she says. But, studying mirror-image pain in patients suffering from shingles – a condition caused by the virus that produces chicken pox in children, which inflicts adults with a painful rash or blisters on one side of the body – she showed that the answer is even more of a mystery – nerve damage on one side can actually lead to "crossover" nerve damage in the exact same spot on the opposite side of the body. "Many people interpreted our shingles study as due to just the virus getting into the spinal chord and traveling over to the opposite side of the body, and that certainly is a reasonable interpretation, and the most obvious one," Oaklander says. But she had seen this crossover effect in patients with all kinds of injures, such as cut fingers, sprained ankles and broken legs. So she went on to study the mirror-pain related to direct injuries where no viruses were involved. (C) ScienCentral, 2000-2005.

Keyword: Pain & Touch
Link ID: 7336 - Posted: 06.24.2010

An understanding of exactly how the brain controls breathing is fundamental to the treatment of respiratory disorders. We know that breathing is an automatic rhythmic process that persists without conscious effort whether we are awake or asleep, but the question that has intrigued many scientists for well over 100 years is what maintains this almost fail safe vital rhythm throughout life? Experimental Physiology editor Julian Paton invited two world renowned scientists Dr. Guyenet from the University of Charlottesville and Dr. Richerson from Yale University, to use the journal as a forum to discuss the issue and attempt to resolve their differences in opinion. Both authors agree that the respiratory rhythm requires specialised nerve cells (central chemoreceptors) to power the rhythm, but the issue highly debated by Guyenet and Richerson is the precise location and cell types involved. Guyenet proposes that these nerve cells are located in a ventral area of the brainstem (the retrofacial region) and loaded with a transmitter substance called glutamate. Their close proximity to the ventral surface of the brain allows them to sense and react to changes in the pH of the cerebrospinal fluid; this is deemed an essential property of a central chemoreceptor. Richerson, on the other hand, stipulates that central chemoreceptors are found close to the midline blood vessels of the brainstem allowing them to 'taste' the pH of the blood. His cells do not contain glutamate but a substance called serotonin.

Keyword: Miscellaneous
Link ID: 7335 - Posted: 05.12.2005

Michael Hopkin The season in which a woman is born influences the age at which she will go through the menopause, suggests a survey of northern Italians. The survey, which looked at nearly 3,000 post-menopausal women at three clinics, revealed that those born in March showed the earliest menopause, at an average age of 48.9 years. At the other end of the scale, those born in October remained fertile until an average age of 50.3, with many lasting beyond 55. The difference may arise because spring babies tend to be born with a smaller stash of eggs in their ovaries, suggests Angelo Cagnacci of the Modena General Hospital, who led the study. They might therefore run out earlier in life, leading to an earlier menopause. Cagnacci's team quizzed the women on the age at which they entered menopause, and a suite of other factors thought to influence menopause timing: the age at which they first became fertile, whether they ever smoked, their education level and their type of employment. After accounting for these differences, a clear seasonal pattern emerged, the team reports in the journal Human Reproduction1. Previous studies have shown other differences based on time of birth. Babies born in autumn tend to be heavier, for example, and to live longer. ©2005 Nature Publishing Group

Keyword: Biological Rhythms; Sexual Behavior
Link ID: 7334 - Posted: 06.24.2010

By JUDITH GROCH The little old lady with the fine white hair and the sky-blue raincoat was there every day, sitting on a couch in the lobby of our apartment building. I remembered her from the time before her brain began to shred. We'd meet and nod hello in the elevator, but back then I paid no more attention to her than to most of the other tenants who came and went in our busy building. Now you couldn't avoid her. Every morning she would descend from her apartment on the 11th floor to plant herself in her new public sitting room. Day after day we found her there, half inside her head, where chaos was closing in fast; half outside, trying to make sense of the world as it hurried by. "Good morning, dearie," she would say as we emerged from the elevator or returned to the building. We were all "dearies," a label that still survived deep in the tangled cells of her dying brain. Sometimes she would applaud us, clapping as we came and went. Copyright 2005 The New York Times Company

Keyword: Alzheimers
Link ID: 7333 - Posted: 05.11.2005

DURHAM, N.C. -- Monkeys that learn to use their brain signals to control a robotic arm are not just learning to manipulate an external device, Duke University Medical Center neurobiologists have found. Rather, their brain structures are adapting to treat the arm as if it were their own appendage. The finding has profound implications both for understanding the extraordinary adaptability of the primate brain and for the potential clinical success of brain-operated devices to give the handicapped the ability to control their environment, said the researchers. Led by neurobiologist Miguel Nicolelis of Duke's Center for Neuroengineering, the researchers published their findings in the May 11, 2005, issue of the Journal of Neuroscience. Lead author on the paper was Mikhail Lebedev in Nicolelis's laboratory. Other coauthors were Jose Carmena, Joseph O'Doherty, Miriam Zacksenhouse, Craig Henriquez and Jose Principe. The work was supported by the Defense Advanced Research Projects Agency, the James S. McDonnel Foundation, the National Institutes of Health, the National Science Foundation and the Christopher Reeve Paralysis Foundation. In the study, Lebedev performed detailed analysis of the mass of neural data that emerged from experiments reported in 2003, in which the researchers discovered for the first time that monkeys were able to control a robot arm with only their brain signals. © 2001-2005 Duke University Medical Center

Keyword: Robotics
Link ID: 7332 - Posted: 06.24.2010

Nicholas Wade, New York Times Using a brain imaging technique, Swedish researchers have shown that gay and straight men respond differently to two odors that may be involved in sexual arousal, and that the gay men respond in the same way as women. The new research may open the way to studying human pheromones and provide a biological basis for sexual orientation. Pheromones, which are chemicals given off by one individual to stir some behavior in another of the same species, are known to govern sexual activity in animals. But the role they play, if any, in human sexual attraction is a matter much in dispute. The new research supports the existence of human pheromones. It is being reported today in the Proceedings of the National Academy of Sciences by Dr. Ivanka Savic and colleagues at the Karolinska Institute in Stockholm. The two chemicals in the study were a testosterone derivative produced in men's sweat and an estrogen-like compound found in women's urine. Both have long been suspected of being pheromones. Most odors cause specific smell-related regions of the human brain to light up when visualized by a PET scanner, a form of brain imaging that tracks blood flow and, by inference, illustrates sites where neurons are active. ©2005 San Francisco Chronicle

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 7331 - Posted: 06.24.2010

Irvine, Calif., -- A treatment derived from human embryonic stem cells improves mobility in rats with spinal cord injuries, providing the first physical evidence that the therapeutic use of these cells can help restore motor skills lost from acute spinal cord tissue damage. Hans Keirstead and his colleagues in the Reeve-Irvine Research Center at UC Irvine have found that a human embryonic stem cell-derived treatment they developed was successful in restoring the insulation tissue for neurons in rats treated seven days after the initial injury, which led to a recovery of motor skills. But the same treatment did not work on rats that had been injured for 10 months. The findings point to the potential of using stem cell-derived therapies for treatment of spinal cord damage in humans during the very early stages of the injury. The study appears in the May 11 issue of The Journal of Neuroscience. "We're very excited with these results. They underscore the great potential that stem cells have for treating human disease and injury," Keirstead said. "This study suggests one approach to treating people who've just suffered spinal cord injury, although there is still much work to do before we can engage in human clinical tests." Acute spinal cord damage occurs during the first few weeks of the injury. In turn, the chronic period begins after a few months. It is anticipated that the stem cell treatment in humans will occur during spinal stabilization at the acute phase, when rods and ties are placed in the spinal column to restabilize it after injury.

Keyword: Regeneration; Stem Cells
Link ID: 7330 - Posted: 05.11.2005

By Judy Skatssoon, ABC Science Online We're smarter and more creative lying down than standing up, says a researcher who believes this helps to explain Archimedes' eureka moment. Darren Lipnicki from the school of psychology at the Australian National University (ANU) found that people solve anagrams more quickly when they are on their backs than on their feet. He said his research, which will be published in the journal Cognitive Brain Research, relates to how neurotransmitters are released. Lipnicki tested 20 people, who were asked to solve 32 five-letter anagrams, such as 'osien' and 'nodru' while standing and lying down. "I found anagrams were solved more quickly lying down than standing up," he said. "[Often] the solution just pops into the mind similar to the 'aha' or 'eureka' experience associated with large-scale creative breakthroughs. "In that sense anagrams replicate that experience because it's easier to solve them, or solve them more rapidly, lying down. That suggests that creative thinking might also be facilitated when lying down." Lipnicki said his finding relates to the difference in brain chemistry, specifically the release of the neurotransmitter noradrenaline, when lying down or standing up. Copyright © 2005 Discovery Communications Inc.

Keyword: Miscellaneous
Link ID: 7329 - Posted: 06.24.2010

DALLAS - - Barbara Baas ran away from home and tried to kill herself as a teenager. As an adult, she has tried more than 15 varieties of antidepressants. But, thanks to a new weapon, she has finally reached a truce in a 45-year battle. Mrs. Baas says a new treatment for depression is changing her life - so much so that she's willing to drive 115 miles five days a week from Decatur to UT Southwestern Medical Center where she is participating in an experimental study. She undergoes transcranial magnetic stimulation (TMS), a noninvasive, nonpharmacological technology, in which short pulses of magnetic energy stimulate nerve cells in a specific area of the brain - an area that research has shown to be associated with depression. Barbara Baas is undergoing transcranial magnetic stimulation, a new noninvasive treatment for depression that uses magnetic energy to stimulate nerve cells in the brain. Dr. Mustafa Husain, professor of psychiatry at UT Southwestern, is admini-stering the treatment. UT Southwestern is one of 14 sites in the United States, Australia and Canada participating in the clinical trial for TMS. It is being evaluated for treating moderate, chronic and recurring depression, particularly in people who have responded poorly to antidepressant medications. Copyright 2005. The University of Texas Southwestern Medical Center at Dallas

Keyword: Depression
Link ID: 7328 - Posted: 05.11.2005

A study stopped early on safety grounds may still hold the key to a vaccine for Alzheimer's disease, say researchers. An international team tried to boost the body's immune system by injecting patients with the beta amyloid protein that causes the disease. The study was halted in 2002 after a some of the hundreds of patients who took part developed brain inflammation. But two long-term follow up studies, published in Neurology, suggest many patients actually benefited. The results renew hope that it may be possible to develop a vaccine which slows, or even prevents development of Alzheimer's. Now a new vaccine study - which doctors hope will avoid the problems of the 2002 trial - is being launched at 30 centres in the US. Results from the long-term follow up studies show 59 out of 300 patients who received at least one dose of the vaccine produced a significant immune response. This group performed significantly better on a series of memory tests than those who received a dummy injection. Brain scans also showed that their brains shrank in size - possibly because of a removal of built-up beta amyloid deposits. And some of those who responded to the vaccine also showed decreased levels of a protein linked to brain cell death in their spinal fluid. Dr Sid Gilman, of the University of Michigan, was one of those who stopped the original trial. He is also lead author of one of the new papers. He said: "The idea of inducing the immune system to view beta amyloid as a foreign protein, and to attack it, holds great promise. "We now need to see whether we can create an immune response safely and in a way that slows the progression of Alzheimer's disease and preserves cognition." (C)BBC

Keyword: Alzheimers
Link ID: 7327 - Posted: 05.10.2005

By LAWRENCE K. ALTMAN Cocaine users face a newly discovered and possibly fatal risk: coronary aneurysms, a ballooning of the walls of coronary arteries. The condition increases the chance of suffering a heart attack, even years after users stop the drug, researchers in Minnesota are reporting. In an angiogram, the white arrows point to ballooning in the right coronary artery of a 49-year-old man who had used cocaine. The risk of developing an aneurysm was four times as high among cocaine users in their mid-40's as among nonusers in the same age group, according to the study, reported yesterday in the journal Circulation, which is published by the American Heart Association. Aneurysms occurred in 30.4 percent of cocaine users in the study compared with 7.6 percent of non-users. Precisely how much cocaine is needed to produce the aneurysms is not known, but the frequency of use was clearly linked to development of aneurysms, said Dr. Timothy D. Henry, a co-author of the study. "The risk was definitely more common in people who used cocaine at least once a week," said Dr. Henry, who directs research at the Minneapolis Heart Institute Foundation at Abbott Northwestern Hospital. Copyright 2005 The New York Times Company

Keyword: Drug Abuse
Link ID: 7326 - Posted: 05.10.2005

By Samantha Sordyl For most of his career, nationally syndicated cartoonist Scott Adams has needed just two hours to produce a three-panel episode of "Dilbert," his celebrated comic strip satirizing cubicle life and misguided management. Those two hours take him from initial pencil sketch to the final inking of such beloved miscreants as Dogbert, the evil management consultant, who emerges from the pen in "one unbroken smooth line" that extends from his nose to his tail, Adams said. But one morning last November, working in his home office in Dublin, Calif., Adams, 47, found that smooth line nearly impossible to execute. "My pinky started moving again," he said. "Specifically, my pinky flexes. It goes stiff; it goes straight out." That was a cue that his focal dystonia was flaring up to threaten his career once again. Adams was diagnosed with the condition -- a neurological movement disorder, marked by involuntary muscle spasms--back in 1992, around the time he launched "Dilbert." The problem affects his right hand -- the one he uses to draw. "I would look at [my fingers] and tell them to do one thing, and they would do jagged things instead," Adams recalled. "I'd have full muscle control for everything -- except putting a pen to a piece of paper." © Copyright 1996-2005 The Washington Post Company

Keyword: Miscellaneous
Link ID: 7325 - Posted: 06.24.2010

The brain reacts differently to the faces of people from different races, research shows. When volunteers looked at pictures of African-Americans, the brain area that processes emotions became active, a study in Nature Neuroscience found. When they looked at photos of Caucasian faces, the activity was much less. This held true regardless of the race of the observer, which the authors say could mean the patterns reflect learned cultural responses to racial groups. But experts criticised the way the study was carried out and said it was impossible to draw any definite conclusions. Previously, researchers had show that pictures of African-American faces activated the amygdala in Caucasian people. It had been suggested that this might be due to lack of familiarity with other races. But the latest findings, from the University of California, Los Angeles, suggest novelty is not important, since African-American volunteers also had increased activity in the amygdala when they looked at faces of strangers of the same race as themselves. Dr Matthew Lieberman and his team said it was possible that this reflected negative cultural attitudes toward African-Americans. When they asked the 22 volunteers to choose the verbal label for the race of the person in the picture that they were shown, they said they found this dampened down the effect. They said this may have been useful during evolution "to allow controlled processing responses to threat to override automatic responses." (C)BBC

Keyword: Emotions
Link ID: 7324 - Posted: 05.10.2005

Several recent publications have highlighted the neural complexity and intelligence associated with the brains of birds. Many studies suggest that the neural seat of both working memory and executive control - which together encompass planning, creativity, reasoning, abstraction, and most of the other higher-order cognitive properties humans like to claim as their own - lies within the prefrontal cortex. In a new study, Jonas Rose and Michael Colombo investigate the neural basis of executive control in homing pigeons by recording from the nidopallium caudolaterale (NCL), a region of the avian brain considered analogous to the mammalian prefrontal cortex. They show that neurons in the NCL selectively fire when the birds are told to remember and stop firing when they are told to forget. The authors trained five pigeons on a directed forgetting test, a variation on the classic match-to-sample test. After viewing sample stimuli consisting of one of two shapes (a circle or dot) or colors (red or white), the birds were cued to remember or forget the sample (signaled by either a high- or low-frequency tone or one of two distinct patterns). A delay period followed these cues. If a forget cue was presented, the trial ended after the delay, and no memory test was given. If the remember cue was presented, the birds were given a memory test in which they saw two stimuli after the delay; if they responded to the sample stimulus (by pecking on a key), they were rewarded with wheat.

Keyword: Learning & Memory
Link ID: 7323 - Posted: 05.10.2005

A biologist at Washington University in St. Louis has shown that for some fish species, females prefer males with larger sexual organs, and actually choose them for mating. That does not exclude males with an average-sized sex organ, called a gonopodium. These fish out-compete the larger-endowed males in a predator-laden environment because they have a faster burst speed than the males with larger genitalia, who lose out because the size of their organ slows them down, making them ripe for capture by larger fish. Brian Langerhans, Washington University biology graduate student in Arts & Sciences, has performed studies on mosquitofish (guppy-like fish, about an inch long) and found that female mosquitofish spend 80 percent more time with males who have a large gonopodium. "A male with a larger gonopodium has a higher chance of mating, but in a predator environment he has a higher probability of dying," Langerhans said. "That's the cost, the tradeoff. On the other hand, we found that in predator-free environments gonopodia size was larger, as there is minimal cost for large genitalia in that environment. Bigger is better for mating, but smaller is better for avoiding predation." Langerhans and colleagues reported their findings in the May 9 on-line issue of Proceedings of the National Academy of Sciences. Langerhans specializes in the study of ecological factors that shape the evolution of body forms. Male genitalia are more variable than just about any other body form studied, and there is a significant cadre of evolutionary biologists studying this field because genital shape – morphology – is one of the chief characters that taxonomists use to distinguish between closely related species.

Keyword: Sexual Behavior; Evolution
Link ID: 7322 - Posted: 06.24.2010

Your nose, whether big or small, male or female, heterosexual or homosexual, may play a big role in selecting your potential mate. According to scientists at the Monell Chemical Senses Center in Philadelphia, one person's preference for another person's body odor depends in part upon the gender and sexual orientation of both sender and receiver. "Our findings support the contention that gender preference has a biological component that is reflected in both the production of different body odors and in the perception of and response to body odors," remarks Monell neuroscientist Charles Wysocki, PhD. Wysocki and Yolanda Martins, PhD co-directed the research effort. In the study, 82 heterosexual and homosexual men and women were asked to indicate their preference for the odors of underarm sweat collected from 24 odor donors of varied gender and sexual orientation. Subjects made four comparisons, evaluating and chosing between odors from (i) heterosexual males versus gay males, (ii) heterosexual males versus heterosexual females, (iii) heterosexual females versus lesbian females, and (iv) gay males versus lesbian females. Homosexual men and lesbian women had patterns of body odor preferences that were different from those of heterosexual men and women. In particular, gay men were strikingly different from heterosexual men and women and from lesbian women, both in terms of which body odors gay men preferred and how their own body odors were regarded by the other groups. Gay men preferred odors from gay men and heterosexual women, whereas odors from gay men were the least preferred by heterosexual men and women and by lesbian women.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 7321 - Posted: 05.10.2005

BURLINGTON, Vt. – Often considered a relic of the 1970's culture, marijuana is no longer a baby boom generation issue. Today, nearly 50 percent of U.S. teenagers try marijuana before they graduate high school, and by 12th grade, about 21 percent are regular users. Consequently, treatment for marijuana dependence is on the rise, but, researchers have discovered, there's a catch – withdrawal symptoms, much like those experienced by people quitting cigarettes, cocaine or other drugs, may make abstinence more difficult to achieve. A new study in today's edition of the journal Drug and Alcohol Dependence shows that teens that use marijuana frequently also may face the same withdrawal symptoms that have been found to challenge adult marijuana users trying to quit. Ryan Vandrey, a graduate student in psychology, and Alan Budney, Ph.D., associate professor of psychiatry and psychology at the University of Vermont, studied 72 adolescent marijuana users seeking outpatient treatment for substance abuse. Participants in the study were heavy marijuana users ages 14 to 19, who were primarily male Caucasians, and who completed study questionnaires. Nearly two-thirds of the participants reported experiencing four or more symptoms of marijuana withdrawal, including anxiety, aggression, and irritability. More than one-third of participants reported four or more symptoms that occurred at a moderate or greater severity level. "In the adolescents who provided information, we observed a lot of variability regarding the presence and severity of withdrawal symptoms, which is consistent with what we have seen in several studies of adults who use marijuana frequently," said Vandrey.

Keyword: Drug Abuse
Link ID: 7320 - Posted: 06.24.2010

Smelling a male pheromone prompts the same brain activity in homosexual men as it does in heterosexual women, a new study has found. It did not excite the sex-related region in the brains of heterosexual males, although an oestrogen-derived compound found in female urine did. The testosterone-derived chemical AND is found in male sweat and is believed to be a pheromone. It activated the anterior hypothalamus and medial preoptic area of gay men and straight women alike. Researchers led by Ivanka Savic at the Karolinska University Hospital in Sweden believe this brain region integrates the hormonal and sensory cues used in guiding sexual behaviour. The research demonstrates a likely link between brain function and sexual orientation, Savic suggests. But she told New Scientist that the study “does not answer the cause-and-effect question”. So the brain-activation of gay men by AND may contribute to sexual orientation of those men, or simply be the result of their orientation and sexual behaviour. She added that the brain scans revealed no anatomical differences between any of the participant’s brains. The team observed 36 healthy men and women, who were exposed in turn to AND, the oestrogen-derived compound EST and other odours, including lavender oil, cedar oil, eugenol and butanol. © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 7319 - Posted: 06.24.2010

By ANDREW POLLACK Is it a drug in search of a disease, or simply an affliction in need of better publicity? One of the afflicted is Peter Pagan. After suffering a severe brain injury in a fall, he would burst into tears at the slightest provocation, even when he was not feeling sad. "The physical therapist would say, 'You're doing well' and he would just start crying," said his wife, Julie. "He cried, I would say, 40 or 50 times a day. It was awful. I just didn't know what to do." But Mr. Pagan, 73, a retired engineer from La Palma, Calif., who still has trouble speaking, has been keeping his tears in check, his wife said, since he started taking an experimental drug developed by Avanir Pharmaceuticals of San Diego. Avanir hopes that the drug, Neurodex, will win federal approval by the end of this year as a treatment for the uncontrollable laughing or crying that can be caused by various neurological diseases or injuries. As one doctor described the odd syndrome in a 1989 article, "Pathologic laughter is devoid of any inner sense of joy and pathologic weeping of any feeling of inner sorrow." Besides federal approval, though, Avanir faces two other potential obstacles. Some critics say that the condition, in people who are typically fighting much more serious health problems, does not warrant drug therapy. And many affected patients and their doctors may not be aware that it is a syndrome with a variety of names and a possible treatment. Copyright 2005 The New York Times Company

Keyword: Emotions
Link ID: 7318 - Posted: 05.09.2005