Scientists at UCL (University College London) have discovered that even wasps are driven by their status. The study, published today in Nature, shows that lower-ranked female wasps work harder to help their queen than those higher up the chain because they have less to lose, and consequently are prepared to take more risks and wear themselves out. The study, funded by the Natural Environment Research Council (NERC), reveals that those higher up the chain and therefore with a greater chance of being the next in line to breed are much lazier than their lower-ranked nest-mates: rather than use up their energy in foraging to feed the queen's larvae, high-rankers sit tight on the nest and wait for their chance to become queen themselves. Dr Jeremy Field, UCL Department of Biology, said: "Helpers wait peacefully in an age-based queue to inherit the prize of being the queen or breeder in the group. The oldest female almost always becomes the next breeder. The wasps in this queue face a fundamental trade-off: by working harder, they help the group as a whole and as a result indirectly benefit themselves, but they simultaneously decrease their own future survival and fecundity because helping is costly. It involves energy-expensive flight to forage for food, and leaving the nest is dangerous. We have found that the brighter the individual wasp's future, the less likely it is to take risks by leaving the safety of its nest to forage for food."

Keyword: Evolution
Link ID: 8906 - Posted: 05.11.2006

A question long debated among Alzheimer's disease researchers has been definitively answered by scientists at the Gladstone Institute of Neurological Disease in San Francisco. Using a unique mouse model, Gladstone Investigator Yadong Huang, MD, PhD, and his team have proven that, under certain conditions, neurons produce Alzheimer's-linked apolipoprotein E. Also known as apoE, this cholesterol-carrying protein has three common forms, one of which, apoE4, is the major known genetic risk factor for Alzheimer's disease, according to studies published around the world in recent years. Until now, most researchers have believed that apoE is synthesized in the brain solely in such cells as astrocytes, microglia, and ependymal layer cells. Controversial for the last decade has been the question of whether or not neurons, which make thought and memory possible by transmitting electrical signals, can produce apoE. The Gladstone study, published in the May 10 issue of the Journal of Neuroscience and highlighted in its "This Week in the Journal" section, proves that neurons, too, produce apoE, but only in response to injury to the brain. Key to the finding has been the development of a mouse model that is uniquely capable of alerting researchers whenever and wherever the apoE gene is expressed. Huang and his team have succeeded in making one of the two alleles of the apoE gene produce a green fluorescent protein that represents apoE, while the remaining allele functions normally. Thus, under a microscope, the bright green fluorescence, dubbed EGFPapoE, shows researchers wherever the apoE gene is expressed.

Keyword: Alzheimers
Link ID: 8905 - Posted: 05.11.2006

Carl T. Hall, Chronicle Science Writer Lesbians seem to have different brain circuitry than heterosexual women, processing the aroma of sex hormones in a way more similar in some respects to the brain response of straight men, a new study has found. A team of neuroscientists in Sweden already has reported evidence suggesting that the brains of men and women, as well as the brains of gay men and straight men, handle male and female hormone smells in distinct ways. On Monday, the same researchers, led by Ivanka Savic of the Stockholm Brain Institute and Hans Berglund of the Karolinska University Hospital, reported similar differences in women. Results appear in the latest Proceedings of the National Academy of Sciences. Twelve women identified as strongly homosexual were subjected to brain scans while the scientists presented an array of aromas, in particular a sample of male and female sex hormones. A group of women identified as straight were also presented the aromas. The results showed that while a part of the brain called the anterior hypothalamus -- which is linked to sexual behavior, among other things -- tended to light up in the straight women, the lesbians showed no reaction. On the other hand, lesbians tended to react to male as well as female hormones in the part of the brain that handles routine odors. ©2006 San Francisco Chronicle

Keyword: Sexual Behavior
Link ID: 8904 - Posted: 06.24.2010

Memory allows us to do more than just store telephone numbers and directions to the post office. It is a repository for lost worlds, which we can recreate years later. The Nobel Prize-winning neuroscientist Eric Kandel did just that during his lecture at the New York Academy of Sciences on March 2, 2006, as part of the Readers & Writers lecture series. Kandel, now 76, drew his audience back to his youth in Vienna in the 1930s. To convey the trauma of being a Jewish boy during the Nazi occupation of Austria, he recalled his ninth birthday. "I'd gotten a number of toys, the most magical was a little shiny car I could control remotely," Kandel said. But that joy turned to terror. It was 1938, the year the Nazis had invaded Austria. "Two days later, Nazi police officers came and told us we had to leave the house," Kandel recalled. "They sent us to live with another family. When we came back, the apartment had been essentially emptied out. Everything was gone." Today Kandel understands a great deal about how he can manage to hold memories such as these. He escaped from Austria to the United States, where he trained as a neuroscientist. He went on to have a spectacular career probing the biological basis of the mind, winning the Nobel Prize in Physiology or Medicine in 2000. Kandel has woven together recollections of his life, his research, and the evolution of modern neuroscience into a memoir and intellectual history, In Search of Memory: The Emergence of a New Science of Mind. ©2006 New York Academy of Sciences,

Keyword: Learning & Memory
Link ID: 8903 - Posted: 06.24.2010

A new way to preserve the cells that surround and protect nerves could lead to new treatments for demyelinating diseases such a multiple sclerosis, a research team reports in the May 10, 2006, issue of the Journal of Neuroscience. The approach grew out of a novel explanation, quickly gaining followers, for the mechanism of nerve damage caused by multiple sclerosis. Instead of concentrating on the alterations that result in autoimmune assaults on the nervous system, researchers led by Brian Popko of the University of Chicago have focused on a set of factors that prevent recovery from the inflammatory attacks. A series of papers from Popko's lab has demonstrated that interferon-gamma -- a chemical signal used to activate the immune system -- plays a critical role in damaging the cells that produce myelin, the protective coating that lines healthy nerves. Interferon not only leaves these cells, called oligodendrocytes, incapable of repairing the damage but can also kill them directly. "Interferon-gamma is not normally found in the nervous system," said Popko, the Jack Miller Professor of Neurological Diseases at the University of Chicago, "but it can gain entry after an inflammatory flare-up. We previously showed how it harmed oligodendrocytes. Here we confirm its direct harmful effects on those cells and demonstrate one way of protecting them." The researchers produced a series of transgenic mice. In one set they introduced genes that produced interferon-gamma within the central nervous system. In another set they also introduced a gene (known as suppressor of cytokine signaling 1, or SOCS1) that blocked the response of myelin-producing cells to interferon-gamma.

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 8902 - Posted: 05.10.2006

Some people meditate to clear their minds or to relieve the stresses of daily life. Others hope to find enlightenment and reach nirvana. It's estimated that ten million Americans practice some form of meditation regularly. "Meditating is about training the mind in effect, it's a technique, it's a tool, so its training the mind to be more focused and to be more mindful moment to moment," explains George Pitagorsky, a management consultant who practices and teaches meditation at the New York Insight Meditation Centre. "It increases concentration capability — less spacing out, much more ability to focus on a particular chosen point of reference," he says. But the benefits of meditation may not be only in the mind. Massachusetts General Hospital's Sara Lazar says she can see physical changes in the brains of people who routinely meditate. "Meditation can have a serious impact on your brain long beyond the time when you're actually sitting and meditating, and this may have a positive impact on your day-to-day living," says Lazar, an assistant in psychology at Massachusetts General Hospital and an instructor at Harvard Medical School. Lazar found that certain parts of the brain were thicker for meditators. As she reported in the journal NeuroReport, Lazar and her research team used a MRI brain scanner to compare the brains of people who practiced Insight meditation every day, with non-meditators. "These are not monks; these are just people who choose to meditate for about 45 minutes a day every day," she says. © ScienCentral, 2000-2006.

Keyword: Stress
Link ID: 8901 - Posted: 06.24.2010

ANN ARBOR, Mich.---Despite research efforts to find modern factors that would explain the different life expectancies of men and women, the gap is actually ancient and universal, according to University of Michigan researchers. "Women live longer in almost every country, and the sex difference in lifespan has been recognized since at least the mid-18th century," said Daniel J. Kruger, a research scientist in the U-M School of Public Health and the Institute for Social Research. "It isn't a recent trend; it originates from our deep evolutionary history." This skewed mortality isn't even unique to our species; the men come up short in common chimps and many other species, Kruger added. Kruger and co-author Randolph Nesse, a professor of psychology and psychiatry and director of the Evolution and Human Adaptation Program, argue that the difference in life expectancy stems from the biological imperative of attracting mates. "This whole pattern is a result of sexual selection and the roles that males and females play in reproduction," Kruger said, "Females generally invest more in offspring than males and are more limited in offspring quantity, thus males typically compete with each other to attract and retain female partners." For example, in common chimps, the greatest difference in mortality rates for males and females occurs at about 13 years of age, when the males are just entering the breeding scene and competing aggressively for social status and females.

Keyword: Sexual Behavior; Evolution
Link ID: 8900 - Posted: 05.10.2006

By Jennifer Viegas, Discovery News —Monkeys drink more alcohol when housed alone, and some like to end a long day in the lab with a boozy cocktail, according to a new analysis of alcohol consumption among members of a rhesus macaque social group. These and other observed behaviors strongly correspond with human patterns of alcohol use. Researchers attribute a predisposition to alcohol abuse in some monkeys and people to a combination of genetic and environmental factors. In the study subjects, "blood alcohol levels often exceeded the .08 percent level, which is the legal limit for most states in the U.S.," said Scott Chen, one of the study’s authors and a researcher at the National Institutes of Health Animal Center in Maryland. The study, recently published in the journal Methods, also found that booze affects monkeys much the same way it affects people. "It was not unusual to see some of the monkeys stumble and fall, sway, and vomit," Chen added. "In a few of our heavy drinkers, they would drink until they fell asleep." © 2006 Discovery Communications Inc.

Keyword: Drug Abuse; Stress
Link ID: 8899 - Posted: 06.24.2010

Roxanne Khamsi Women may be able to tell whether a man is child-friendly simply by looking at his face – and this could influence how attractive they find him as a potential long-term partner. But for a spring fling or a summer love, women seek men with high levels of testosterone who don’t care much for children. James Roney at the University of California, Santa Barbara, US, and his colleagues asked 39 undergraduate men to look at pairs of pictures each consisting of a photo of an adult and a photo of an infant. The men were asked which photo they preferred. Researchers also took saliva samples from the male volunteers to determine their testosterone levels. Each man was then asked to maintain a neutral expression while researchers photographed his face. Then, 29 female undergraduates rated the photographed male faces according to how much they believed the men liked children. Researchers found that women could often correctly guess which men preferred the infant photos. The women were also asked which men they would choose for a short fling and which for a long-term relationship. Those men perceived as child-friendly were more likely to be selected for a long-term relationship. In addition, the female volunteers were told to rate the men’s faces in terms of masculinity. The men selected as most masculine by the women were confirmed by their saliva tests to be the ones with the highest testosterone levels. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8898 - Posted: 06.24.2010

By BENEDICT CAREY Handling a gun stirs a hormonal reaction in men that primes them for aggression, new research suggests. Psychologists at Knox College in Galesburg, Ill., enrolled 30 male students in what they described as a taste study. The researchers took saliva samples from the students and measured testosterone levels. They then seated the young men, one at a time, at a table in a bare room; on the table were pieces of paper and either the board game Mouse Trap or a large handgun. Their instructions: take apart the game or the gun and write directions for assembly and disassembly. Fifteen minutes later, the psychologists measured saliva testosterone again and found that the levels had spiked in men who had handled the gun but had stayed steady in those working with the board game. The "taste sensitivity" phase of the experiment was in fact intended to measure aggressive impulses. After the writing assignment, the young men were asked to rate the taste of a drink, a cup of water with a drop of hot sauce in it. They were then told to prepare a drink for the next person in the experiment, adding as much hot sauce as they liked. Copyright 2006 The New York Times Company

Keyword: Aggression; Hormones & Behavior
Link ID: 8897 - Posted: 05.09.2006

By LARRY ZAROFF, M.D. My anesthesiologist, Dr. G., was young, handsome, athletic and slick. Relaxed and happy. A triumphant life. In less than a minute, he had my epidural in place. The needle into my spinal space, the medication injected. A perfect anesthetic for an operation on my left lower leg. I did not have to wait long before my legs lost all feeling, as if U.P.S. had picked them up for delivery to Kauai. They disappeared. Later, Dr. G. would do the same. At that moment, the greater loss was my right leg. My left was already short a functional Achilles tendon, the thick cord — a bass's string — that connects the calf muscles to the heel bone. Without that anchor, the lower leg is useless. I had been playing tennis with my cousin, a pediatrician. I had two lessons that afternoon. Pediatricians can be as competitive as surgeons, and if you're in your mid-50's, you should either stretch before playing or forget about charging the net for drop shots. I heard and felt the second shot, the pop as my Achilles tendon wandered away from its roots and migrated up my calf. It hurt, and I could not walk. A definite weakness. Copyright 2006 The New York Times Company

Keyword: Drug Abuse
Link ID: 8896 - Posted: 06.24.2010

By NATALIE ANGIER Oh, mothers! Dear noble, selfless, tender and ferocious defenders of progeny all across nature's phylogeny: How well you deserve our admiration as Mother's Day draws near, and how photogenically you grace the greeting cards that we thrifty offspring will send in lieu of a proper gift. Cute? You think so. But this mother gave birth to two cubs and when one of them thrived, she left the "spare" behind without a backward look. Here is a mother guinea hen, trailed by a dozen cotton-ball chicks. Here a mother panda and a baby panda share a stalk of bamboo, while over there, a great black eagle dam carries food to her waiting young. We love you, Mom, you're our port in the storm. You alone help clip Mother Nature's bloodstained claws. But wait. That guinea hen is walking awfully fast. In fact, her brood cannot quite keep up with her, and by the end of the day, whoops, only two chicks still straggle behind. And the mama panda, did she not give birth to twins? So why did just one little panda emerge from her den? As for the African black eagle, her nest is less a Hallmark poem than an Edgar Allan Poe. The mother has gathered prey in abundance, and has hyrax carcasses to spare. Yet she feeds only one of her two eaglets, then stands by looking bored as the fattened bird repeatedly pecks its starving sibling to death. Copyright 2006 The New York Times Company

Keyword: Sexual Behavior
Link ID: 8895 - Posted: 05.09.2006

By Michael S. Wolfe The human brain is a remarkably complex organic computer, taking in a wide variety of sensory experiences, processing and storing this information, and recalling and integrating selected bits at the right moments. The destruction caused by Alzheimer's disease has been likened to the erasure of a hard drive, beginning with the most recent files and working backward. An initial sign of the disease is often the failure to recall events of the past few days--a phone conversation with a friend, a repairman's visit to the house--while recollections from long ago remain intact. As the illness progresses, however, the old as well as the new memories gradually disappear until even loved ones are no longer recognized. The fear of Alzheimer's stems not so much from anticipated physical pain and suffering but rather from the inexorable loss of a lifetime of memories that make up a person's very identity. Unfortunately, the computer analogy breaks down: one cannot simply reboot the human brain and reload the files and programs. The problem is that Alzheimer's does not only erase information; it destroys the very hardware of the brain, which is composed of more than 100 billion nerve cells (neurons), with 100 trillion connections among them. Most current medications for Alzheimer's take advantage of the fact that many of the neurons lost to the disease release a type of chemical communicator (or neurotransmitter) called acetylcholine. Because these medicines block an enzyme responsible for the normal decomposition of acetylcholine, they increase the levels of this otherwise depleted neurotransmitter. The result is stimulation of neurons and clearer thinking, but these drugs typically become ineffective within six months to a year because they cannot stop the relentless devastation of neurons. Another medication, called memantine, appears to slow the cognitive decline in patients with moderate to severe Alzheimer's by blocking excessive activity of a different neurotransmitter (glutamate), but investigators have not yet determined whether the drug's effects last more than a year. © 1996-2006 Scientific American, Inc.

Keyword: Alzheimers
Link ID: 8894 - Posted: 06.24.2010

BETHESDA, MD. (May 9, 2006) – Put a mouse or a rat under stress and what does it do? It stops eating. Humans should be so lucky. When people suffer nontraumatic stress they often head for the refrigerator, producing unhealthy extra pounds. When Syrian hamsters, which are normally solitary, are placed in a group-living situation, they also gain weight. So scientists at the Center for Behavioral Neuroscience at Georgia State University are using hamsters as a model for human stress-induced obesity. They want to begin unraveling the complex factors that lead people to eat when under stress and hope that the information can eventually be used to block appetites under this common scenario. The study, "Social defeat increases food intake, body mass, and adiposity in Syrian hamsters," by Michelle T. Foster, Matia B. Solomon, Kim L. Huhman and Timothy J. Bartness, Georgia State University, Atlanta, appears in the May issue of the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology published by The American Physiological Society. In the study, the researchers look at nontraumatic stress -- the stress we experience in everyday life, such as getting stuck in traffic or trying to complete a major project at work. It is distinct from traumatic stress, such as suffering the death of a loved one. Traumatic stress typically dulls the human appetite, said Bartness, the study's senior researcher and an authority on obesity.

Keyword: Stress; Obesity
Link ID: 8893 - Posted: 06.24.2010

Michael Hopkin We are not the only animals to give ourselves names, says research on bottlenose dolphins. The dolphins' distinctive whistles may function as individual calling cards, allowing them to recognize each other and even refer to others by name. The research reveals that bottlenose dolphins (Tursiops truncatus) each have their own personalized whistle, which is recognized by other dolphins even from a synthetic version played through a speaker. This suggests that the creatures recognize these as names in their own right, rather than identifying individuals based simply on the sound quality of their voice. The dolphins have also been heard using each others' names in their 'conversation' — meaning that they may be able to call their comrades during social interactions. The calls may be used to bind groups together in the wild where individuals cannot always see each other, or to coordinate their delicately complex hunting manoeuvres. The effect was revealed in bottlenose dolphins living at in Sarasota Bay, Florida. The individual whistles of these dolphins are well known, as they have been involved in capture and recording studies since 1975. Researchers created artificial versions of specific dolphins' signature calls and played them to other dolphins from the group. Dolphins were more likely to turn towards the speaker if it was playing the call of a close relative, rather than an unrelated dolphin, the team reports in Proceedings of the National Academy of Sciences1. ©2006 Nature Publishing Group

Keyword: Language
Link ID: 8892 - Posted: 06.24.2010

Helen Pearson Autistic patients may lack the ability to daydream normally, say researchers who have found that these people's brains act differently when they are taking a break. Neuroscientists know that a certain network of brain regions fires up when our minds wander, and that this is important for pondering and reminiscing about ourselves, others and our emotions. Other studies have hinted that autistic patients, who have learning and social problems, might have abnormalities in this region but the details have been unclear. To pin down whether autism is related to these brain changes, Daniel Kennedy of the University of California at San Diego, La Jolla, and his colleagues studied 15 adults with some form of autism and 14 healthy controls. The team used functional magnetic resonance imaging (fMRI) to scan the 'daydreaming' regions, which lie in the middle of the brain. In healthy people, these spots become active when the brain is resting — and dampen down when the brain is working hard at a mental puzzle, the researchers confirmed. They also showed that part of the network revs up when participants read emotional words, such as 'murder' or 'blood', compared with bland ones such as 'table'. But the brains of autistic patients revealed a different picture. Their daydreaming network seemed permanently dampened; it did not show increased activity during rest and was not roused by emotional words. ©2006 Nature Publishing Group

Keyword: Autism
Link ID: 8891 - Posted: 06.24.2010

Alison Abbott Researchers have concluded that a gene responsible for most cases of hereditary deafness may have an unexpected benefit: it may protect you from infection. Stella Man, a member of David Kelsell's team at Queen Mary, University of London, spoke at the European Society of Human Genetics meeting in Amsterdam today, 8 May. She announced that the Cx26 protein encoded by a deafness gene might help wounds to heal. Faster healing should help to prevent infection, for example by limiting bacteria's access to the blood after surgery, she says. "It's speculation, but maybe the Cx26 deafness mutations have been selected owing to their beneficial effects on wounds." Kelsell identified the link between the Cx26 gene and deafness almost a decade ago1. Mutations of the gene are surprisingly common in all populations, from Africa to Europe and Asia, he says, but cause deafness only in those who inherit a mutated gene from both parents. A high frequency of mutation in any gene implies that there may be an evolutionary benefit for carriers. "It is well known that various genetic mutations that cause sickness in particular geographical areas sometimes also protect against local diseases, so there is a trade-off," says Kelsell. ©2006 Nature Publishing Group

Keyword: Hearing; Genes & Behavior
Link ID: 8890 - Posted: 06.24.2010

Patrick Barry Lesbian and heterosexual women respond differently to specific human odours, a brain-scanning study has found. The homosexual women showed similar brain activity to heterosexual men when they inhaled certain chemicals, which may be pheromones, the researchers say. "But our study can't answer questions of cause and effect," cautions lead researcher Ivanka Savic at the Karolinska Institute in Stockholm, Sweden. "We can't say whether the differences are because of pre-existing differences in their brains, or if past sexual experiences have conditioned their brains to respond differently." Savic and her colleagues asked 12 lesbian women and 12 heterosexual women to breathe concentrated samples of two steroids: EST, which is derived from oestrogen and found in the urine of pregnant women; and AND, which is derived from progesterone and found in men’s armpit sweat. Positron emission tomography (PET) scans revealed which regions of the women's brains responded to each chemical. When the heterosexual women smelled AND their brains showed activity in the anterior hypothalamus, a region of the brain thought to process sexual cues. But EST only produced activity in the olfactory region of their brains, the area that processes smells. The lesbians, however, only showed activity in the olfactory region whichever odour they smelled. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 8889 - Posted: 06.24.2010

A contraceptive pill also used to treat acne is being investigated over concern it may increase the risk of depression. The Medicines and Healthcare Products Regulatory Authority (MHRA) which licenses drugs has ordered the review into Dianette. The charity April (Adverse Psychiatric Reactions Information Link) submitted a dossier on the drug. April says it has details of more than 100 women who say they became seriously depressed after taking Dianette. Dianette is licensed as a hormone treatment for severe acne, but only in cases where other treatments, such as oral antibiotics, have not worked. It is also an effective contraceptive, but doctors have been warned that they should not prescribe it solely for that purpose because it has a higher risk of blood clots than other similar combination pills. Women who take it are supposed to stop within three or four months of their skin problems clearing up. However, April says that it knows of some women who have been taking the drug for years. The manufacturer's information leaflet does warn that one possible side effect of taking the drug is "mild depression". Millie Kieve, who runs April, said it was clear that this was an under-statement. She said: "The doctor should warn these girls that if they are depressed, it could be Dianette, instead of putting them on antidepressants." Ms Kieve said she had been told by the MHRA was particularly concerned by the charity's evidence that doctors were continuing to prescribe Dianette solely as a contraceptive. The MHRA said it was hoped the findings of its review would be submitted to its expert advisory group on medicines for women's health at the end of May. The authority granted a licence to an identical pill called Clairette in March - but said there was no reason at the time not to. (C)BBC

Keyword: Depression; Hormones & Behavior
Link ID: 8888 - Posted: 05.08.2006

Parkinson's disease may trigger symptoms by crippling the key energy-producing "boiler room" of brain cells, research suggests. Two studies by US and Korean scientists focused on a mutant protein implicated in inherited Parkinson's. In tests on fruit flies, they found it disabled energy-producing cell structures called mitochondria, damaging cells controlling movement. The research is published online by the journal Nature. Previous research has established that an inherited form of early-onset Parkinson's - autosomal recessive juvenile parkinsonism (AR-JP) - is caused by mutations in a gene called PINK1. The researchers, from the University of California in Los Angeles and the Korea Advanced Institute of Science and Technology, explored the effect on the equivalent gene in the fruit fly, Drosophila. Flies with a mutant form of the gene suffered defects in the mitochondria. This appeared to cause serious damage to muscle cells, which led to movement problems. It also appeared to lead to trigger degeneration of cells that transport a key chemical, dopamine, around the brain. Parkinson's has been linked to a shortage of dopamine, which is known to play a key role in the co-ordination of movement. Both muscle cells and dopamine-transporting brain cells consume large amounts of energy, and thus are more reliant than most on healthy mitochondria. The researchers also produced evidence suggesting that the PINK1 protein has a knock-on effect on another molecule - Parkin - which has also been implicated in Parkinson's. They suspect that the two proteins both play an important role in keeping the mitochondria healthy. (C)BBC

Keyword: Parkinsons
Link ID: 8887 - Posted: 05.08.2006