A spray that helps increase women's enjoyment of sex has undergone successful trials. The spray, developed by Australian company Acrux, contains the male sex hormone testosterone. It was initially designed with post-menopausal women in mind, but has also been shown to work for young women with a low libido. Acrux plans to carry out larger trials, and does not expect the spray to come to market for several years. The spray was tested over four months in three doses on 261 women with a low sex drive and low testosterone levels. Researchers found a statistically significant rise in the number of satisfying experiences at the end of the fourth month for women taking the second highest dose of the spray. The only apparent side effect was a small increase in body hair among some of the participants. This prompted two women taking the highest dose of the spray to drop out of the study. The spray delivers testosterone and a substance to ensure the hormone is held in the skin and absorbed over 24 hours - similar to the way sunscreen remains on the skin. Lead researcher Professor Susan Davis, of Monash University, Principal investigator, said previous research had focused on postmenopausal women known to have low testosterone levels. "But many younger women also report having low sexual interest and enjoyment and traditionally," she said. (C)BBC

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 6849 - Posted: 02.10.2005

San Diego, CA, -- Researchers in California, Israel, and Germany have compared three distantly related species – baker’s yeast, a worm, and the fruit fly – and reported that protein “wiring” connections in one species are often conserved in all three. This first-of-its-kind analysis of three higher level organisms published in the February 8 issue of Proceedings of the National Academy of Sciences supports both the concept of a basic wiring diagram for all eukaryotic cells, and the idea that more selective pharmaceuticals could be designed to tweak the wiring plan of human cells to more effectively treat diseases while also generating fewer side-effects. These wiring diagrams show the patterns of protein interactions in the cells of yeast, worm, and fly that are involved in an essential garbage-disposal function. The horizontal dotted lines indicate protein similarities between species, and the thick and thinner solid lines indicate direct and indirect, respectively, protein interactions within a species. Click here for high-res version. "We're basically now able to open the hood of yeast, worm, and fly cells and look at the protein interactions inside,” said Trey Ideker, a bioengineering professor at the University of California, San Diego and one of the nine co-authors of the paper. “Ultimately, this type of wiring analysis will help us more fully explain how the diversity of life developed on the planet, and more practically, how a pathogen differs from its human host, or a diseased cell differs from it healthy counterpart at the most informative level of detail.”

Keyword: Evolution
Link ID: 6848 - Posted: 06.24.2010

The adult male zebra finch knows only one scratchy tune learned in its youth, which it performs repeatedly and intensely when females are listening. But occasionally, the finch might improvise, experimenting with a slower, more sultry variation or emphasizing different notes. Neurobiologists studying the finch now say the improvisation arises from a component of a crucial learning circuit in a section of the forebrain that seems to generate the trial and error necessary to master sophisticated motor skills, such as singing in birds or speech and sports in humans. "It means this part of the brain is important for instructing or allowing changes in the song," said Mimi Kao, first author of a paper in the February 10, 2005, issue of the journal Nature that demonstrates how the region modulates bird song in real time. Kao, a Howard Hughes Medical Institute (HHMI) predoctoral fellow, is in the final months of her doctoral training in the laboratory of co-author Allison Doupe at the University of California, San Francisco's Keck Center for Integrative Neuroscience. A similar brain pathway in humans may explain how children learn to talk by listening to themselves and others, and how adults learn and hone new motor skills, such as tennis. The process relies on feedback about what works and what doesn't, also called experience-dependent or performance-based learning.

Keyword: Language
Link ID: 6847 - Posted: 02.10.2005

All is fair in love and war—especially when the two are intertwined. Just ask the male Australian cuttlefish. "The male cuttlefish has quite a challenge on his hands when it comes to the end of their yearly life cycle," explains Roger Hanlon, senior scientist at the Marine Biological Laboratory. "There are four, five even ten males for every female on the spawning grounds, so the challenge they face is, 'How do I get my genes into the next generation?' There's enormous competition among the males for the relatively few females that are on the spawning ground." Hanlon and his team spent five spawning seasons observing cuttlefish underwater in a remote coastal area of Australia. As one might expect, the largest males used their size advantage to find a female partner and guard her from other males. Hanlon observed that smaller males were able to get to the female while the guard male was fighting other males away, or by meeting the female in a "secret rendezvous" under a rock, for instance. But he found that the small males with the biggest success rate employ the same camouflage trick that allows them to escape predators: these so-called "sneaker" males change their skin pattern and body shape to disguise themselves as females, and swim right past a large guard male, who thinks he's getting another girlfriend. © ScienCentral, 2000- 2005.

Keyword: Sexual Behavior
Link ID: 6846 - Posted: 06.24.2010

The red Mozambique spitting cobra stiffens, fixing its gaze on the victim's face, which is moving backwards and forwards in front of it. For several seconds it remains erect like this; then its head flashes forwards. For an instant the fangs in front of its pale pink throat are visible in its wide-open mouth, as they squirt the venom at high pressure towards the victim. On the plastic visor two red spiral patterns appear. The eyes behind it look surprisingly unperturbed. "I sprayed the visor beforehand with rhodamine," Katja Tzschätzsch calmly explains, "It's a pigment which dyes liquids red. This makes the traces of venom easier to see." In her undergraduate dissertation the trainee teacher investigated what spitting cobras aim at when spitting. "In the literature it often says: they aim at the eyes," her supervisor Dr. Guido Westhoff, junior lecturer in Professor Horst Bleckmann's team, explains. "However, up to now nobody has investigated it." The cocktail of toxins partly consists of nerve poisons, but also contains components which are harmful to tissue. Through a narrow channel in their fangs the snakes can spray the liquid at high pressure – similar to a bullet in the barrel of a gun. If they manage to hit an eye, the sensitive cornea reacts with severe stinging pain. In the worst case these burns can ultimately lead to blindness.

Keyword: Neurotoxins
Link ID: 6845 - Posted: 06.24.2010

Although most parents, educators, and researchers believe that children can't learn specific words until well into their second year, children younger than 1 year can, in fact, learn certain words for things that are not a regular part of their daily lives, according to new research being published in the January/February 2005 issue of the journal, Child Development. The findings, based on research by Graham Schafer, D.Phil., of the University of Reading in Reading in the United Kingdom, suggest that what is considered a "formal" learning of a word may be underway long before children say much. "It appears that young children may understand word use more flexibly than scientists and parents have previously thought," says Dr. Schafer. The findings call into question earlier beliefs that before their second year most children only learn words for things they are interested in, or when those words are linked to certain routines, such as "bath," "car," or "cat." To investigate this issue, Dr. Schafer asked parents of 52 nine-month-olds to use 12 board books and a set of 48 picture cards depicting common objects like keys, apples, fish, and chairs in simple games with their children four times a week for up to 10 minutes a session. The games were designed to build on the kind of routines parents already used in the home: Naming and pointing, sorting, finding the odd one out. No reading was required for either parents or children.

Keyword: Language
Link ID: 6844 - Posted: 02.10.2005

— The octopus may have flexible arms, but it uses them in the same three-jointed way as vertebrates, a finding that sheds intriguing light on how limbs evolved, a new study says. An Israeli research team filmed octopuses as they stretched out an arm from a hidey-hole in an aquarium to grab a piece of food with their tentacles and bring it to their mouths. The octopuses, filmed about a hundred times, used a vertebrate-like strategy to carry out the complex movement. Even though their arms are supple and rubbery, the creatures stiffened the limbs through muscle control and articulated them in a way eerily like that of animals with rigid skeletons, the scientists found. To carry out the fetching movement, the octopus flexes its arm to form three "joints," located in similar locations to the shoulder, elbow and wrist in humans. Copyright © 2005 Discovery Communications Inc.

Keyword: Muscles
Link ID: 6843 - Posted: 06.24.2010

Jessica Ebert Being 'broken-hearted' as a result of emotional trauma may be a more apposite turn of phrase than we imagined. US researchers have shown how sudden emotional stress can release hormones that stun the heart into submission, resulting in symptoms that mimic a typical heart attack. People suffering from stress cardiomyopathy, or 'broken-heart syndrome', seem to be having a heart attack: they have chest pain, fluid in the lungs, shortness of breath and heart failure. But although the ability of the heart to pump is significantly reduced and the heart muscle is weakened, it is not killed, or infarcted, as in a classic attack. "The tissue is alive," says Hunter Champion of Johns Hopkins Hospital in Baltimore, Maryland, who led the study. "It's just not moving." In 1999, Champion and a fellow Johns Hopkins cardiologist, Ilan Wittstein, noticed something unusual about certain heart-attack patients. They were particularly struck by results from postmenopausal women who had experienced an intense emotional event before their attack, such as the loss of a loved one or a court appearance. These patients had unique electrocardiogram and ultrasound patterns, lacked coronary artery disease and recovered quickly. ©2005 Nature Publishing Group

Keyword: Emotions; Stress
Link ID: 6842 - Posted: 06.24.2010

This remarkable collection of over 30 essays makes its first impact for two reasons. Firstly, it is beautifully produced and profusely illustrated, while being marketed at a reasonable price. The publishers deserve praise for this increasingly rare event in hardback publishing. Secondly—and one must take this to be an editorial decision—the focus of the collection is the history, not of tobacco or opium, but of smoke and smoking. This simple manoeuvre opens up what can only be called a cultural universe, one with its origins in the earliest known history of humankind and which takes us right up to current debates about very modern objects and their uses: the cigarette and its alleged dangers or the recent fashion for smoking rocks of cocaine, now of course called "crack." As a result, the central importance of smoking in all cultures and the highly complex and differing practices and meanings behind smoking are wonderfully displayed. Smoking as religious ritual; smoking as a possible source of medical healing in early modern Europe; smoking as pleasure, espe-cially in groups—all receive attention. And this is where the illustrations and the photographs play such a vital part, providing amazing examples of artefacts (pipes, above all), places (the opium den, the cocktail bar), and icons who almost are their cigarettes or their cigars (Bogart, Dietrich, Castro). Text and illustrations blend perfectly. © 2005 BMJ Publishing Group Ltd

Keyword: Drug Abuse
Link ID: 6841 - Posted: 06.24.2010

By Susan Okie Rudolph L. Leibel’s genes may have predisposed him to become a scientist, but his decision to spend his life trying to discover the causes of obesity was environmental happenstance, the result of a chance encounter. In the spring of 1977, Randall, a severely overweight child, and Randall’s mother showed up at the pediatric clinic of Cambridge Hospital in Massachusetts, where Leibel was a specialist in hormone disorders. Leibel could find no evidence that hormone deficiency or, indeed, any other known medical condition, was the cause of Randall’s obesity. But what struck the young doctor was the response of Randall’s mother when Leibel told her there was little he or anyone else could do for her son: “Let’s get out of here, Randall,” she snapped. “This doctor doesn’t know s--t.” Chastened by her words, Leibel soon traded his hospital post for the low-paying toil of a rookie laboratory scientist. At the Rockefeller University laboratory of Jules Hirsch, a leading figure in research on obesity, Leibel and Hirsch conducted extensive studies of weight homeostasis: how the body responds both to weight gain and weight loss by fighting to restore the status quo ante. Copyright © Natural History Magazine, Inc., 2005

Keyword: Obesity
Link ID: 6840 - Posted: 06.24.2010

An international team of scientists has used gene therapy in two separate studies to renew brain cells and restore normal movements in monkeys and rats with a drug-induced form of Parkinson's disease. The research, detailed online in the scientific publications Brain and The Journal of Neuroscience, essentially describes one strategy to halt Parkinson's disease at its onset and another strategy to treat the devastating side effects that occur when treating the disease in its later stages. By inserting corrective genes into the brain, scientists studying small monkeys called marmosets prevented brain damage by producing therapeutic levels of a protein that helps nourish brain cells, said Ron Mandel, Ph.D., a scientist with the University of Florida's McKnight Brain Institute and Genetics Institute who was part of the research team. The protein, called GDNF, short for g lial cell line derived neurotrophic factor, is believed to preserve brain cells and could provide protection against Parkinson's disease. But its use has been debated since trials in humans ended last year without showing clinical improvements. Amgen, the world's largest biotechnology company, conducted the trials and later halted use of the drug because of safety concerns, creating an outcry from hopeful Parkinson's patients. Copyright © 2004 | University of Florida

Keyword: Parkinsons
Link ID: 6839 - Posted: 06.24.2010

ATLANTA-- A steroid hormone released during the metabolism of progesterone, the female sex hormone, reduces the brain's response to stress, according to research in rats by scientists at Emory University School of Medicine, the Yerkes National Primate Research Center and Atlanta's Center for Behavioral Neuroscience. The scientists found evidence that the progesterone metabolite allopregnanolone reduces the brain's response to corticotropin-releasing factor (CRF), a peptide hormone that plays an important role in the stress response in animals. The finding, which was reported in the Nov. 10, 2004 edition of the Journal of Neuroscience, could provide a new drug target for treating anxiety and depression in women. In the study, Emory researchers Donna Toufexis, PhD, Michael Davis, PhD and Carrie Davis, BS, and Alexis Hammond, BS, of Spelman College, compared how female rats with different levels of the sex hormones, estrogen and progesterone, reacted to loud noises after injections of CRF into the brain's lateral ventricles. CRF injections usually increase the "acoustic startle response" in this test used to gauge stress and anxiety, a phenomenon called CRF-enhanced startle. In the first experiment, the scientists compared acoustic startle responses after CRF injection in an estrogen-only group, an estrogen-plus-progesterone group and a control group that did not receive any sex hormones. All the rats lacked ovaries and the ability to produce sex hormones naturally. Acoustic startle response was unaffected in the estrogen-only group and the control group. In the estrogen-plus-progesterone group, however, CRF-enhanced startle was significantly lower than in the other groups.

Keyword: Stress; Hormones & Behavior
Link ID: 6838 - Posted: 02.09.2005

UCI researchers have determined that chronic nicotine exposure worsens some Alzheimer’s-related brain abnormalities, contradicting the common belief that nicotine can actually be used to treat the disease. In the latest online edition of the Proceedings of the National Academy of Sciences, the researchers report that chronic nicotine exposure increases neurofibrillary tangles – the bundles of fibers that are one of the two neuropathological hallmarks of the disease, the other being clump-like plaques. Previous animal studies had suggested that nicotine reduces the number of these plaques; however, this possible benefit is outweighed by the increase in tangles. The paper also will appear in the Feb. 22 print edition of PNAS. Alzheimer’s disease is a slow, progressive disease and the most common cause of dementia among the elderly in the United States, affecting 4.5-5 million adults – 10 times more than those affected by Parkinson’s disease. The disease is marked by the accumulation of two distinct brain lesions – beta-amyloid plaques and neurofibrillary tangles – which accumulate in specific brain regions critical to learning and memory. © Copyright 2002-2005 UC Regents

Keyword: Alzheimers
Link ID: 6837 - Posted: 06.24.2010

By ANAHAD O'CONNOR THE FACTS The amplified din of a rock concert or a few hours at a noisy bar can numb your hearing for an evening. But permanent damage? Studies show that most people regularly experience levels of noise and music that over time can leave them hard of hearing for life. Noise from recreational and work-related activities is responsible for hearing loss in about a third of hearing-impaired Americans. The damage is often accompanied by a nonstop buzzing called tinnitus. Dr. Eric Genden, an otolaryngologist at Mount Sinai, says it usually takes repeated doses of noise at levels from 90 decibels to 140 decibels to cause permanent harm. Those levels, he said, are fairly common. The clamor at most bars and clubs registers 110 to 120 decibels. Amplified music at a concert can reach 120 decibels and climb to an ear-rattling 130 decibels, rivaling the sound of a jet taking off. Sound from headphones can reach 100 decibels - louder than a lawn mower. Copyright 2005 The New York Times Company

Keyword: Hearing
Link ID: 6836 - Posted: 02.08.2005

By BENEDICT CAREY Thousands of brain-damaged people who are treated as if they are almost completely unaware may in fact hear and register what is going on around them but be unable to respond, a new brain-imaging study suggests. The findings, if repeated in follow-up experiments, could have sweeping implications for how to care best for these patients. Some experts said the study, which appeared yesterday in the journal Neurology, could also have consequences for legal cases in which parties dispute the mental state of an unresponsive patient. The research showed that the brain-imaging technology, magnetic resonance imaging, can be a powerful tool to help doctors and family members determine whether a person has lost all awareness or is still somewhat mentally engaged, experts said. "This study gave me goose bumps, because it shows this possibility of this profound isolation, that these people are there, that they've been there all along, even though we've been treating them as if they're not," said Dr. Joseph Fins, chief of the medical ethics division of New York Presbyterian Hospital-Weill Cornell Medical Center. Dr. Fins was not involved in the study but collaborates with its authors on other projects. Copyright 2005 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 6835 - Posted: 02.08.2005

By SANDRA BLAKESLEE There comes a point in every great mystery when a confusing set of clues begins to narrow. For scientists who study autism, that moment may be near, thanks to a combination of new tools for examining brain anatomy and of old-fashioned keen observation. Within the last year, several laboratories have reported finding important new clues about the mysterious syndrome that derails normal childhood brain development. For the first time, they say, a coherent picture is emerging. In autism, subtle brain abnormalities are present from birth. Infants and toddlers move their bodies differently. From 6 months to 2 years, their heads grow much too fast. Parts of their brain have too many connections, while other parts are underconnected. Moreover, their brains show signs of chronic inflammation in the same areas that show excessive growth. The inflammation appears to last a lifetime. "Autism is still a confusing disorder, but one thing is now clear," said Dr. Pat R. Levitt, a neuroscientist who is the director of the Kennedy Center for Research on Human Development at Vanderbilt University in Nashville. "There is a specific disruption of circuitry in brain development. We can really dig in and begin to explain the splintered brains of autistic children." Copyright 2005 The New York Times Company

Keyword: Autism
Link ID: 6834 - Posted: 02.08.2005

David Perlman, Chronicle Science Editor Parrots can chat with humans, pigeons can tell a Picasso painting from a Monet and, in the Galapagos islands, Darwin's finches can spear insects with tools they make from cactus spines -- but, contrary to what scientists have long believed, none of them is acting merely on blind instinct or unconscious responses to training. What those birds are doing, instead, is being smart -- displaying "complex cognitive behavior" as modern brain researchers call it. The new understanding comes from a recent series of experiments and comparative studies of the brain structures of birds, humans and other mammals. So branding slow-witted people as "birdbrains" is merely ignoring reality, says a group of the world's leading neuroscientists who study the brain circuitry of birds, fish and mammals and who propose that it's high time to abandon old words to describe the brain and adopt a new and better account of brain evolution. "Evolution has created more than one way to generate complex behavior -- the mammal way and the bird way, and they're comparable to one another," said Erich Jarvis, a Duke University neurobiologist. "In fact, some birds have evolved cognitive abilities that are far more complex than many mammals." Jarvis heads an international consortium of scientists who have worked for more than seven years studying the brains of birds, fish and mammals. They have published a report on their conclusions in the February issue of the journal Nature Reviews Neuroscience. ©2005 San Francisco Chronicle

Keyword: Evolution; Intelligence
Link ID: 6833 - Posted: 06.24.2010

Jocelyn Lowinger, ABC Science Online Laughing literally changes the way you see the world, an Australian researcher has shown. Professor Jack Pettigrew, from the University of Queensland, reports his findings on how laughter affects visual perception in the latest issue of the journal Clinical and Experimental Optometry. Pettigrew, who is director of the university's Vision Touch and Hearing Research Centre, says each eye sends an image to a different side of the brain. Normally the brain regularly, but unnoticeably, switches attention between the two competing images, a situation known as binocular rivalry. In optical illusions like the Necker cube, pictured below, the regular switch in perception allows us to see the cube as if it's from two different angles, cyclically. "Normally people just don't see both [versions] at the same time," he says. But when you laugh the images blend together and the illusion is lost leaving only a flat 2D drawing. "If you see both images together you can be pretty sure you're seeing from both hemispheres at the same time," he says. ©2005 ABC

Keyword: Emotions; Vision
Link ID: 6832 - Posted: 06.24.2010

By observing the mating rituals of fruit flies after different mating experiences, researchers have gained a greater understanding of how animals organize their behavioral responses in complex learning situations. The work is reported in the February 8 issue of Current Biology by Dr. Leslie Griffith, of Brandeis University, and colleagues at the University of Toronto. Previous studies have demonstrated successful learning in the fruit fly (Drosophila melanogaster) under standardized laboratory conditions. In natural environments, however, the cues for learning are rarely clear cut. Animals are routinely presented with complex stimuli and must alter their behavior to give priority to the most relevant recent experience. To investigate how animals deal with learning multiple cues, we have explored the ability male fruit flies learn to discriminate between the pheromonal signals given off by different types of female flies. Male courtship in fruit flies is a stereotyped set of behaviors that are stimulated by pheromones given off by female flies. Although courtship appears to be a "hard-wired" aspect of the male nervous system, the decision to initiate the behavior can be influenced by previous experience.

Keyword: Sexual Behavior; Learning & Memory
Link ID: 6831 - Posted: 02.08.2005

CHICAGO – Significantly higher levels of antisocial behavior were found in seven-year-old children whose mothers were depressed during the child's first five years of life, according to an article in the February issue of Archives of General Psychiatry, one of the JAMA/Archives journals. "Children of depressed mothers have elevated conduct problems, presumably because maternal depression disrupts the caregiving environment," according to background information in the article. Researchers have identified three possible explanations for the association between a mother's depression and antisocial behavior (ASB) in their children: 1) depressed women are likely to have antisocial personality traits related to depression, 2) are likely to bear children with antisocial men, 3) and the children of depressed mothers may inherit a genetic predisposition for antisocial disorders. Julia Kim-Cohen, Ph.D., from King's College London, and colleagues investigated the association between maternal depression and children's ASB. Participants were members of the Environmental Risk (E-Risk) Longitudinal Twin Study, which examined how genetic and environmental factors affected the development of 1,116 sets of twins in England and Wales. The mothers categorized the timing of their depression as: never depressed (n = 728), depressed only before twins' birth (n = 68), depressed only after twins' birth (n = 193), and depressed before and after twins' birth (n = 124). Children's ASB at ages five and seven was determined from mother and teacher reports.

Keyword: Depression; Development of the Brain
Link ID: 6830 - Posted: 06.24.2010