Short-circuiting your nerves By Eric Haseltine Why does your head hurt when you scarf down ice cream too quickly, or your left arm ache when your heart is in trouble? Neuroscientists think that misplaced sensations, called referred pains, arise when sensory fibers from different parts of the body connect to the same nerve cells in the spinal cord or brain stem, confusing your brain about which part of your body the message came from. And, as you are about to learn, these cross-connects are not limited to pain. Experiment 1 Place a teaspoon of black pepper (freshly ground works best) under your nose and inhale until you sneeze. Observe that no matter how hard you try, you cannot keep your eyes open while sneezing. Just as sensory inputs streaming into your brain can sometimes become sidetracked, so too can motor impulses. In this instance, your brain’s commands to the sneeze muscles in both your diaphragm and your throat are cross-connected to the outgoing motor pathways that closed your eyes. © 2003 The Walt Disney Company.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 4543 - Posted: 06.24.2010

By LISA SANDERS, M.D. ''Doctor, I think I look like a man.'' The young woman sat on the examining table. She stared at the ground as she spoke, then looked up, her eyes shiny with tears that didn't spill. ''Really, doctor, I know I look like a man, and I don't understand why.'' She was a young woman with dark curly hair and a pleasant but clearly masculine face and bearing. I'd noticed -- anyone would have -- but I'd been hesitant to bring it up. Somehow, it felt too awkward in our first appointments. I was comfortable asking her intimate details -- was she involved in a sexual relationship? Did she use drugs? Had she ever been the target of abuse? Yet to raise a topic as potentially painful as her appearance felt too intimate -- as if I needed to get to know her better. But it was time to approach the topic, and I was grateful she had brought it up. She explained that she had always been tall and on the heavy side. But in the past few years, she'd put on a lot of weight, though she wasn't sure why. And while she had never gone in for dresses or makeup, she had never been mistaken for a man until the past year. She quit a receptionist job after only a few weeks because so many people called her ''Mr.'' Then, not long ago, while standing in line at the grocery store, a little girl asked her if she was a man or a woman. The child's mother apologized. ''But it didn't make me feel any better,'' she said. ''I just want whatever it is that's happening to me to stop.'' She roughly brushed away the escaping tears. Copyright 2003 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 4542 - Posted: 11.16.2003

By ANDREW POLLACK ANAHEIM, Calif.,— An experimental drug can slow the loss of vision caused by a maddening eye disease that is the leading cause of blindness among the elderly, doctors reported on Saturday. But in a large trial, the drug did not meaningfully improve vision, they said. That contradicts previously reported results that had sent patients flocking to eye doctors for what they thought might be a miracle cure. The drug, called Macugen, is intended to treat the wet form of age-related macular degeneration, a disease that can rob people of the ability to read, drive, recognize faces or watch television. More than 200,000 cases of wet macular degeneration are diagnosed each year in the United States. Copyright 2003 The New York Times Company

Keyword: Vision
Link ID: 4541 - Posted: 06.24.2010

Progestins, synthetic progesterone analogs, joined estrogen as part of hormone replacement therapy (HRT) some two decades ago, to reduce perceived risks of endometrial cancer from estrogen alone. But for almost as long, researchers have suspected that progestins block some benign effects of estrogen replacement, increasing the risk of breast cancer, diminishing estrogen's beneficial effects on the cardiovascular system, and souring mood. So, researchers continue to study progestins in search of safer HRT. Jon Nilsen and Roberta Brinton, University of Southern California, recently showed how natural estrogen and progesterone protect hippocampal neurons from glutamate toxicity. But at least one progestin, medroxyprogesterone acetate (MPA), blocks that protection.1 MPA is the progestin component of Prempro, the HRT used in the Women's Health Initiative (WHI) clinical trials. The US government shut down that arm of the WHI study in July 2002--three years early--after discovering small increases in breast cancer, heart disease, stroke, and pulmonary embolism in women taking the drug. No one argues that MPA is solely responsible for those risk increases, but many argue that the results would have been different for progesterone or different progestins.2 Researchers are not unanimous on MPA, but even its backers concede that the future is gloomy. "The whole idea that progestin is bad and has been responsible for some of the negative findings of the WHI, I really think, is an overextrapolation," says Duke University's Donald McDonnell. He acknowledges candidly, however, that MPA partisans can't overcome its increasingly bad reputation. "There has to be a shift toward a newer progestin purely to address that marketing need," McDonnell says. ©2003, The Scientist Inc.

Keyword: Hormones & Behavior
Link ID: 4540 - Posted: 06.24.2010

To everyone but a frog, one croak probably sounds very like another. But analysis of different croaks has revealed that at least one species of amphibian has developed regional accents in its mating calls. The accented croaks are thought to have developed during the last ice age when populations of pool frogs were separated for thousands of years. The discovery was made during a project to return an extinct species of pool frog to wetlands in Eastern England. The discovery of the frog accents was made by amphibian expert Julia Wycherley who was trying to find out which exact sub-species of pool frog (Rana lessonae) had been living in East Anglia before it became extinct. Ms Wycherley has spent a lot of time listening to frog calls and was convinced that she could hear subtle differences in their mating sounds. (C) BBC

Keyword: Animal Communication; Language
Link ID: 4539 - Posted: 11.15.2003

NewScientist.com news service Soy supplements can decrease normal sexual behaviour by as much as 70 per cent, a study of female rats has shown. The rats were given a commercially available supplement in doses similar to those taken by women. The findings suggest a possible negative side effect for the supplements, which are becoming very popular among US women. Isoflavones, the key compounds in soy, are estrogen-like molecules. Soy supplements are touted as a natural alternative to hormone replacement therapy and recent warnings of the risks of HRT may boost the numbers of women turning to the supplements. © Copyright Reed Business Information Ltd.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 4538 - Posted: 06.24.2010

Exclusive from New Scientist Print Edition. A captive female gorilla has been spotted teaching her daughter how to tend to her newborn. Gorilla mothers are often seen teaching their young to walk and climb, but primatologists believe this is the first report of a mother instructing her daughter on baby care. The daughter, an 11-year-old western lowland gorilla called Ione, had neglected her first baby, which her keepers raised. So for several days after the birth of her second baby at San Diego Wild Animal Park, the keepers and primatologist Masayuki Nakamichi of Osaka University in Japan kept a close eye on her. Initially, Ione simply left her baby on the ground in front of her 21-year-old mother, Alberta, who picked him up and handed him back. When Ione made no move to take the baby, Alberta moved closer pushing the newborn into his mother's face until she took him. Variations on this sequence occurred several times in the first two days. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 4537 - Posted: 06.24.2010

For years, scientists assumed that neurotransmitters, the molecules that transmit messages between neurons, were neatly stored in tiny vesicles. So it was big news when neuroscientists discovered a dozen years ago that a gas--nitric oxide (NO)--could function as a neurotransmitter, because gases cannot be stored in vesicles. Now, they have data that strongly suggest that another gas is also a member of the neurotransmitter club: carbon monoxide (CO). CO is made by an enzyme called heme oxygenase. One form, HO1, releases CO in aging red blood cells. But the function of HO2, a second type that's found in the brain, was mysterious until the early 1990s. Then-graduate student Ajay Verma, in Solomon Snyder's lab at Johns Hopkins University, wondered if the enzyme might produce CO as a neurotransmitter. Verma and his colleagues soon determined that HO2 exists in discrete brain regions, as one would expect of a neurotransmitter, and CO appears to influence key brain enzymes and control intestinal function and ejaculation in mice. A key piece of evidence was still missing. Researchers had no idea how CO production was regulated--a gaping hole, considering that gases cannot be stored for release and must be made on demand when a neuron is stimulated. The first clue to CO's regulation emerged in the 25 September issue of Neuron , when Johns Hopkins postdoctoral fellow Darren Boehning showed that an enzyme called CK2 can activate HO2 by sticking on a phosphate group. CK2, in turn, is activated by protein kinase C, an enzyme that is turned on whenever a neuron fires. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 4536 - Posted: 06.24.2010

East African naked mole-rats, the only known cold-blooded mammal, have shown a rather heated response in lab tests that may have important implications for treating chronic pain in humans. The blind, furless creatures that live underground in colonies lack a body chemical called Substance P, a neurotransmitter normally in the skin that sends pain signals to the central nervous system. The rats feel no immediate pain when cut, scraped or subjected to heat stimuli. They only feel some aches. But when the rats get a shot of Substance P, pain signaling resumes working as in other mammals. "It was a complete surprise when we discovered that the skin of naked mole-rats is missing one of the most basic chemicals that's found in the skin of all other mammals," said Thomas Park, associate professor of biological sciences at the University of Illinois at Chicago and the principal investigator in the research project.

Keyword: Pain & Touch
Link ID: 4535 - Posted: 11.15.2003

By Robert Sanders, Media Relations BERKELEY – The tropical mantis shrimp has the most sophisticated eyes of any creature on the planet, yet it often lives at murky depths where the only light is a filtered, dim blue. Why does it need such complex vision? Marine biologists and physiologists have now discovered at least one use for these eyes in the deep, blue ocean: to see the fluorescent markings mantis shrimp use to signal or threaten one another. The shrimps' characteristic spots are easy to see in shallow water but only dimly visible 40 meters (131 feet) down, so on the ocean floor the crustacean's spots fluoresce yellow-green to enhance their prominence in the dim blue light. Copyright UC Regents

Keyword: Animal Communication; Aggression
Link ID: 4534 - Posted: 06.24.2010

Reduction of agitation leads to less stress for caregiver; better care for patient San Antonio, Texas and Long Branch, N.J. – Results from a Phase II, multi-center study found dronabinol, a synthetic version of the active ingredient in marijuana, reduces agitation in patients with Alzheimer's disease. In addition, the research concluded that reduced agitation may contribute to the relief of caregiver burden associated with the condition. The findings were presented at the American Society of Consultant Pharmacists' 34th annual meeting. "Our results show dronabinol is an effective treatment for behavioral agitation in patients with Alzheimer's and may ultimately help reduce the stress often experienced by caregivers," said geriatrician Joel S. Ross, M.D. a member of the teaching faculty at Monmouth Medical Center and the lead investigator in the study. "While difficult for the patient, the effects of agitation can greatly impact the emotional and physical health of family members and caregivers. By reducing patients' agitation, caregivers are able to focus more time and energy on their patients' overall wellbeing." Dronabinol, marketed as Marinol, is synthetic delta-9-tetrahydrocannabinol (delta-9-THC). Delta-9-THC also is a naturally occurring component of Cannabis sativa L (marijuana). Dronabinol has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of anorexia in patients with HIV/AIDS and for the treatment of nausea and vomiting associated with cancer chemotherapy. Recent clinical tests also have examined dronabinol's potential to relieve symptoms of multiple sclerosis.1

Keyword: Alzheimers; Multiple Sclerosis
Link ID: 4533 - Posted: 06.24.2010

Some of us would never go up and talk to strangers at a party, while others may prefer to work the room. As this ScienCentral News video reports, psychologists could see the signature of shyness imprinted in the brain, from toddlers to twenty-year-olds. The more things change, the more they stay the same? Psychologists at Harvard University and Massachusetts General Hospital found that this old chestnut may be true when it comes to personality traits like shyness. It all started over twenty years ago, when psychologists studied two-year-olds that fell into two categories–inhibited and uninhibited. "Inhibited children were characterized by an aversion to novelty, an aversion to strangers, not liking things that were new, whereas uninhibited children were children who sort of plunged in freely," explains Carl Schwartz, director of the Developmental Psychopathology Research Group at Massachusetts General Hospital and assistant professor of psychiatry at Harvard Medical School . The researchers created a small mechanical robot and wheeled it into the room with the toddlers. "The child who they categorized as inhibited would cry or freeze or run to its mother, whereas a typical uninhibited child would toddle up to the robot and poke it in the eye," says Schwartz. "They were immediately curious and were not put off by the unfamiliarity of that." © ScienCentral, 2000-2003.

Keyword: Development of the Brain
Link ID: 4532 - Posted: 06.24.2010

Sociable mums make much better mothers than less gregarious ones, suggests a new study of baboons. Baby baboons born to outgoing mums who enjoy hanging out with other females are considerably more likely to survive their crucial first year than infants born to less friendly mothers, reveals the behavioural study. Primates and monkeys are unique among animals in the intense social bonds they form. These bonds are thought to have been crucial in the evolution of primates, including humans. Behavioural ecologists have assumed that extrovert behaviour in primates boosts survival by generally making group life easier. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Development of the Brain
Link ID: 4531 - Posted: 06.24.2010

By GINA KOLATA The government should sponsor small clinical trials on whether testosterone therapy can improve conditions like frailty, weakness, failing memories and loss of sexual function in aging men with low levels of the hormone, a committee of the National Academy of Sciences said yesterday. But large long-term studies to see if testosterone can prevent such conditions should be deferred until there is evidence that it works as a treatment, the committee added. The report, by the National Academies' Institute of Medicine, answers a question from the National Institutes of Health, which wanted to know what it should do to forestall a potential disaster as more and more men take testosterone without knowing whether it helps or harms. Copyright 2003 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 4530 - Posted: 11.14.2003

NEW ORLEANS-- Birds aren't born knowing how to sing. Chicks must hear adult songs during a short critical period soon after birth, or they'll be reduced to the avian equivalent of stammering. Now a study presented at the Society for Neuroscience meeting here on 10 November shows that chicks don't need to hear the whole rendition--given the pieces, they can put a song together themselves. Baby birds are all ears, and they remember what they hear. White-crowned sparrows that hatch in the late summer listen to the seasonal songs of nearby males. After a silent winter, in which the adults stop singing, the young sparrows start to perform the song they heard as chicks a year earlier. Neuroscientists have searched in vain for neurons that harbor a song "template"--cells that encode a complete version of the bird's song. Instead, they've found neurons that respond to a portion of the song, usually a few notes, or syllables, at a time. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Evolution; Intelligence
Link ID: 4529 - Posted: 06.24.2010

— Researchers have used ultraviolet light to “weld” a key regulatory protein to its RNA targets, creating a new tool that can be used to identify novel proteins involved in a variety of human diseases. Using this technique, the researchers have identified an array of RNA molecules regulated by the RNA-binding protein, Nova, which has been implicated in an autoimmune neurodegenerative disease. The researchers believe their technique may help in finding the RNA targets of other proteins involved in neurological diseases, including the most prevalent form of mental retardation, the Fragile X syndrome. Robert B. Darnell, a Howard Hughes Medical Institute investigator at The Rockefeller University, led the research team that reported its findings in the November 14, 2003, issue of the journal Science. ©2003 Howard Hughes Medical Institute

Keyword: Genes & Behavior; Development of the Brain
Link ID: 4528 - Posted: 06.24.2010

Such abilities may have influenced human evolution PHILADELPHIA – We may take it for granted that humans can classify each other according to familial or social status, but how did those abilities evolve? In the Nov. 14 issue of the journal Science, researchers at the University of Pennsylvania report that, much like humans, baboons identify each other based on complex rules that determine relationships between families and status or "rank" within their particular family. "Humans organize their knowledge of social relationships into a hierarchical structure, and they also make use of hierarchical structures when deducing relationships between words in language," said Robert Seyfarth, a professor in Penn's Department of Psychology of the School of Arts and Sciences and one of the study's authors. "The existence of such complex social classifications in baboons, a species without language, suggests that the social pressures imposed by life in complex groups may have been one factor leading to the evolution of sophisticated cognition and language in our pre-human ancestors." For the last 12 years, Seyfarth, Dorothy Cheney, a professor in Penn's Department of Biology, and their colleagues have studied a troop of more than 80 baboons in the Okavango Delta of Botswana. Their research explores the cognitive mechanisms that might be the basis of primate social relationships and how such relationships may have influenced the development of human social relationships, intelligence and language.

Keyword: Evolution
Link ID: 4527 - Posted: 06.24.2010

Primping and passing time with peers may serve a serious purpose, suggests a new study by a UCLA-led team of primate researchers. The more time wild female baboons spend in the company of other adult baboons, particularly while occupied with grooming activities, the more likely their offspring are to live until their first birthday, the team reports in the Nov. 14 issue of Science. "Until now, social scientists assumed that because females invest a lot in social relationships, they must gain a lot from those relationships, but we've never been able to make a direct link to reproductive success," said Joan B. Silk, the study's lead author. "These findings provide the first evidence that there's a link between the amount of social involvement and having offspring who survive the critical first year of life."

Keyword: ADHD
Link ID: 4526 - Posted: 11.14.2003

Make advances in understanding why false memories are formed New studies of false memories show that what happens in the brain when memories are established can be as important to the development of false memories as what happens during memory retrieval. Other research shows that specific parts of the brain are more active when a true memory is being retrieved than when a false memory is being retrieved, potentially providing a neural label by which to understand the differences between true and false memories. Memories can be fragile and subject to distortion because we literally cannot record and store all of what we learn and experience. People often mistakenly claim to remember having seen a word or object that is similar to something they saw earlier, according to several studies. Such false memories can have an even greater impact when they manifest in such a way that entirely novel events are implanted into an individual's memory. Such an individual can willingly retrieve these completely false memories, such as being lost in a mall, with surprisingly vivid and specific details. Neuroimaging techniques can help determine if the neural processes driving this retrieval of inaccurate memories are different from those that drive the retrieval of accurate memories. Several research groups are using functional magnetic resonance imaging (fMRI) to address this question. The hope is that neuroimaging can help determine the various potential sources of false memories.

Keyword: Learning & Memory
Link ID: 4525 - Posted: 11.14.2003

In new studies, scientists are discovering the neurobiological underpinnings of romantic love, trust, and even of self. New research also shows that a specific brain area - the amygdala - is involved in the process of understanding the intentions of others, in particular when lying is involved. Using brain imaging, researchers Helen Fisher, Arthur Aron, Lucy Brown and colleagues find that feelings of intense romantic love are associated with specific activity in dopamine-rich brain regions associated with reward and motivation. Those study participants who expressed more romantic passion on a questionnaire showed more brain activity in these regions. Those in longer relationships showed more activation in emotion-related areas as well. And men and women tended to show some different brain responses. The researchers conclude that romantic love may be best classified as a motivation system or drive associated with a range of emotions. Further studies of intense, early stage romantic love may help to define how the brain encodes reward and memory. In this experiment, 17 young men and women who had "just fallen madly in love" were tested with functional magnetic resonance imaging (fMRI) to identify the brain circuitry of romantic love.

Keyword: Sexual Behavior
Link ID: 4524 - Posted: 11.14.2003