The likelihood of a person committing suicide is partly determined as early as at birth, researchers believe. The Swedish team looked at 700,000 adults and found low birthweight and being born to a teenage mother meant a two-fold rise in suicide risk. The report also said risk increased for shorter babies. The authors, from the National Centre for Suicide Research and Prevention in Stockholm, said it proved genetics played an important role in suicides. The researchers followed the adults, who were all born between 1973 and 1980, and assessed the proportion of suicides and attempted suicides between 10 and 26 years of age. The overall suicide rate in Sweden in 1999, when the follow-up exercise finished, was around 20 per 100,000 of the population. Babies weighing 2kg or less were more than twice as likely to commit suicide as adults than those weighing between 3.25kg and 3.75kg, according to the findings published in The Lancet medical journal. Children born to mothers under 19 years old were also more than twice as likely to commit suicide as those born to women aged 20 to 29. (C)BBC

Keyword: Depression; Development of the Brain
Link ID: 6149 - Posted: 09.24.2004

The door to apartment 2F looked like any other. But what lay inside was a shocking sight: Mounds of garbage and trash so tall and so plentiful that there was almost no way to open the front door. "There was a huge table there piled high with stuff and there was a tiny little path. In some places you had to sneak by it sideways," says Ron Alford who runs Disaster Masters, Incorporated www.theplan.com , a company dedicated to helping extreme pack rats clean house. "Stuff was just stacked up and the cockroaches were walking up behind it and making a mess on the wall." After an 85-year-old man broke his leg tripping over the clutter, his family called Alford, who with a crew of six men and women waded through an apartment packed full of old roller skates, radio parts and airplane model material. Nearly three days later, the carpets and floors began to see daylight. Alford has a special word he coined to describe such hoarding behavior: disposophobia. "When you trip and fall on your own stuff, when you're ashamed or afraid to have your friends, relatives or neighbors come into your house and sit down, that's how we draw the line," he says. "Your life has become abysmal because the stuff is overruling your life." © ScienCentral, 2000- 2004.

Keyword: Miscellaneous
Link ID: 6148 - Posted: 06.24.2010

Like estrogen loss in older women, decreased levels of testosterone may put aging men at risk for Alzheimer's disease, according to a new study by USC researchers. The team's findings – appearing as a letter to the editor in the Sept. 22 issue of the Journal of American Medical Association – bolster sparse research on the adverse effects of age-related testosterone depletion in the brain and may lead to future development of hormone replacement therapies. "Our findings strongly suggest that normal age-related testosterone depletion is one of the important changes that promote Alzheimer‚s disease in men," said Christian Pike, senior author of the study and an assistant professor at the USC Leonard Davis School of Gerontology. "Understanding how these changes increase vulnerability to the disease is critical not only for elucidating Alzheimer's development, but also for identifying those persons most at risk," Pike said. While the link between estrogen loss in women and increased susceptibility to a variety of diseases – including Alzheimer's – has long been well established, there has been less focus on the health effects of hormonal depletion in men.

Keyword: Alzheimers; Hormones & Behavior
Link ID: 6147 - Posted: 06.24.2010

Mating with close relatives often leads to no good, so most animals try to avoid it. So pity the female red jungle fowl. With randy and aggressive brethren, they don't have much choice when it comes to mates. But the hens can avoid the ill effects of inbreeding by picking which sperm fertilize their eggs, scientists have discovered. Among promiscuous animals, males and females may have conflicting strategies when it comes to inbreeding. Because males can produce many sperm fairly cheaply, it's no great loss if mating with their mother or sister happens to yield a few bad eggs. But for females, producing eggs requires more effort and they ought to strenuously avoid inbreeding. In the promiscuous red jungle fowl Gallus gallus, the wild progenitor of domestic chickens, the risk of inbreeding is high because hens and cocks stay close to their home turf. Smaller female jungle fowl can do little to resist incest. But because they can store sperm, females may be able to choose whose sperm wins their egg. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 6146 - Posted: 06.24.2010

DURHAM, N.C. -- Neurobiologists have pinpointed the molecular storehouse that supplies the neurotransmitter receptor proteins used for learning-related changes in the brain. They also found hints that the same storage compartments, called recycling endosomes, might be more general transporters for 'memory molecules' used to remodel the neuron to strengthen its connections with its neighbors. They said their finding constitutes an important step toward understanding the machinery by which neurons alter their connections to establish preferred signaling pathways in the process of laying down new memories. Understanding such machinery could also offer clues to how it might degenerate in aging and disease to degrade learning and memory, they said The researchers, led by Michael Ehlers of the Duke University Medical Center and Julie Kauer of Brown University, published their findings in the September 24, 2004, issue of the journal Science. Other co-authors on the paper were Mikyoung Park of Duke, and Esther Penick, Jeffrey Edwards of Brown. Their research was supported by the National Institutes of Health. In their studies, the researches sought to understand how neurotransmitter receptors in the depths of the neuron are carried to the surface -- a process called exocytosis. These receptors are proteins that are activated by bursts of signaling chemicals, called neurotransmitters, launched from another, transmitting neuron. The connection between transmitting and receiving neurons is called the synapse.

Keyword: Learning & Memory
Link ID: 6145 - Posted: 09.24.2004

A handful of genes in a morphine free poppy could hold the key to producing improved pain management pharmaceuticals. Norman, the 'no-morphine' poppy, is superior to morphine producing poppies as it produces thebaine and oripavine – compounds preferred by industry in the manufacture of alternative high value pain-killers. CSIRO's Dr Phil Larkin, and The Australian National University's Anthony Millgate and Dr Barry Pogson have been working with Tasmanian Alkaloids to investigate Norman the morphine-free poppy. "The genes we found behaved differently in Norman compared to standard morphine producing poppies and were consistently associated with the blockage in morphine synthesis and with the accumulation of thebaine and oripavine," Dr Larkin says. "Understanding the genes responsible for the production of morphine, thebaine and oripavine is an important step in further developing poppies that are tailored to produce alternative pharmaceuticals." The morphine free poppy variant, TOP1, was first discovered in 1995 by Tasmanian Alkaloids then released as Norman for commercial production in 1997 in Tasmania where it is now widely grown.

Keyword: Pain & Touch
Link ID: 6144 - Posted: 06.24.2010

Dog walkers know the canine habit of sniffing lampposts for urine only too well. Now, in a novel experiment, a team of scientists and dog trainers have put this traditional canine behaviour to good use – sniffing human urine to detect bladder cancer sufferers. The researchers hope that analysis and identification of the characteristic chemical odorants may lead to non-invasive, early-detection screening methods for bladder cancer in the future. “There had been a series of anecdotal stories about patients whose pet dogs had aroused concern by continually sniffing their moles, which actually turned out to be cancerous. I was pretty sceptical and needed to design a simple experiment to test it,” explained the study’s lead author, Carolyn Willis, from Amersham Hospital in the UK. The impracticalities of training dogs to detect skin cancer using skin biopsies led Willis and colleagues to consider trying bladder cancer detection, using easily obtainable urine samples. The group used urine samples from 36 patients with bladder cancer, and 108 control samples from cancer-free individuals. Six dogs of varying ages and breeds underwent a seven month training course in cancer detection, carried out by trainers from Hearing Dogs for the Deaf. © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6143 - Posted: 06.24.2010

Rats equipped with radios that transmit their brainwaves could soon be helping to locate earthquake survivors buried in the wreckage of collapsed buildings. Rats have an exquisitely sensitive sense of smell and can crawl just about anywhere. This combination makes them ideal candidates for sniffing out buried survivors. For that, the animals need to be taught to home in on people, and they must also signal their position to rescuers on the surface. In a project funded by DARPA, the Pentagon’s research arm, Linda and Ray Hermer-Vazquez of the University of Florida in Gainesville have worked out a way to achieve this. First the researchers identified the neural signals rats generate when they have found a scent that they are looking for. “When a dog is sniffing a bomb, he makes a unique movement that the handler recognises,” says John Chapin, a neuroscientist at the State University of New York in Brooklyn who is collaborating on the project. “Instead of the rat making a conditioned response, we pick up the response immediately from the brain.” © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6142 - Posted: 06.24.2010

Emma Marris Dolphins, when dozing, swim in lazy circles. A new paper uncovers the odd fact that dolphins in the Northern Hemisphere swim in anticlockwise circles, whereas dolphins in the Southern Hemisphere swim in clockwise circles. The marine mammals only sleep with one half of their brains at a time, and continuously swim as they snooze. Wild dolphins, not just captive ones, have been seen to swim in circles when they sleep, and dolphins of various species had previously been shown to move preferentially anticlockwise. That prompted speculation as to why they choose this direction, with explanations relating mainly to the animals' anatomy, perhaps an asymmetry in their brain. But when Paul Manger, a dolphin neuroethologist from Sweden, moved to the University of Witwatersrand in South Africa, he realized that all reports of dolphins swimming anticlockwise round their pools came from the Northern Hemisphere. On a hunch, he went down to the local dolphinarium with a video camera and a Thermos of hot coffee. Four nights of watching the animals produced the surprising result that these Southern dolphins spent 86% of their time swimming clockwise. ©2004 Nature Publishing Group

Keyword: Miscellaneous
Link ID: 6141 - Posted: 06.24.2010

It is well known that obesity has reached epidemic proportions. As waistbands expand, so do the number of health gurus heralding the benefits of portion control and exercise to keep obesity at bay. But with some studies indicating that the rate of obesity is greater in women than in men, could it be that women are at a disadvantage when it comes to these obesity avoidance tactics? Is it possible that females are predisposed to succumb to the temptation to overeat? And could exercise be a less effective method of appetite suppression in women than in men? Researchers at The Florida State University say the answer could be yes. Overeating (hyperphagia) and sedentary behavior are known risk factors for obesity, but research in these areas – especially overeating – has been studied almost exclusively in males. In the new animal study “Diet-induced hyperphagia in the rat is influenced by sex and exercise,” Lisa A. Eckel and Shelley R. Moore (The Florida State University Program in Neuroscience and Department of Psychology) found that female rats are more susceptible than male rats to over consume a palatable, sweetened diet, and that female rats are less likely than male rats to use exercise as a means to control appetite in the presence of such a diet.

Keyword: Obesity
Link ID: 6140 - Posted: 06.24.2010

New studies indicate that a specific type of lipid molecule plays a critical role in controlling the behavior of vesicles that store neurotransmitters within neurons. Neurotransmitters are the chemical messengers that neurons release to communicate with one another. The identification of a regulatory role for the molecule, phosphatidylinositol 4,5 biphosphate, or PtdIns(4,5)P2, provides a new view of the operation of the machinery that produces and recycles synaptic vesicles. Led by Howard Hughes Medical Institute (HHMI) investigator Pietro De Camilli, the researchers published their findings in the September 23, 2004, issue of the journal Nature. De Camilli, HHMI investigator Richard Flavell, Reiko Fitzsimonds, and their colleagues at Yale University School of Medicine collaborated on the studies with Timothy A. Ryan and researchers from the Weill Medical College of Cornell University. Synaptic vesicles are initially loaded with neurotransmitter molecules in the interior of neurons. They then secrete their cargo at synapses — the junctions between neurons. At the synapse, the vesicles undergo a process called exocytosis, in which they fuse with the synaptic plasma membrane and unload their neurotransmitters. Afterward, they are drawn back into the neuron in the process of endocytosis. © 2004 Howard Hughes Medical Institute.

Keyword: Drug Abuse
Link ID: 6139 - Posted: 06.24.2010

By BENEDICT CAREY Last week, a federal advisory panel urged regulators to warn parents that antidepressant drugs not only increase the risk of suicide in some children, but that most have a poor track record in curing their disease. The recommendation came after a yearlong debate over whether the drugs are as safe and effective as advertised. It was based on evidence that a small minority of children show increased signs of suicidal behavior when taking the drugs. Through it all, one of the drugs seemed somehow above the fray: Prozac. Although the warning is recommended for Prozac as well as other drugs, Prozac is still the only one approved by the Food and Drug Administration for the treatment of depression in children and adolescents. A large government-financed trial recently found that it worked better than talk therapy in helping teenagers overcome depression. And when British health officials announced a sweeping ban of antidepressant use in children, which touched off the debate last year, they specifically exempted Prozac. But is it really that different? The short answer is no, experts say. Although chemically distinct from other drugs in the same class, Prozac works on precisely the same principle, they say, and there's no evidence that it is significantly safer or more effective than the others in treating childhood depression. Prozac has shown in several trials that it can relieve depression in youngsters and adolescents significantly better than dummy pills. Such convincing evidence is not available for the other drugs. But, research psychiatrists say, that does not mean the other drugs in the same family do not work in young people, only that they have not been properly tested. Copyright 2004 The New York Times Company

Keyword: Depression
Link ID: 6138 - Posted: 09.22.2004

Monkeys have a lot in common with people, including the ability to procrastinate. Like us, they tend to work harder when the goal is closer, and get lazy when it seems farther away. But researchers at the National Institute of Mental Health (NIMH) have used a genetics trick to turn monkeys into workaholics. "All the animals, including humans, are continually making decisions about the value of a reward and the amount of work or effort it's going to take to get a reward, or desired goal," says Barry Richmond of the NIMH's Laboratory of Neuropsychology. "The cognitive behavior we're studying is this balance between the desire to have the reward and the, if you will, burden of having to work to get it." Richmond and his team taught four monkeys to release a lever to make an onscreen dot change color from red to green. A gray bar on the screen in the background told them how much work remained before they received a reward for their efforts. "Normally when they get a cue that says they have a couple of more trials to do, they tend to work a little more slowly and they tend to make errors," says Richmond. "In trials where they know a reward is coming, they make no errors." © ScienCentral, 2000- 2004.

Keyword: Intelligence; Genes & Behavior
Link ID: 6137 - Posted: 06.24.2010

Now that the human genome has been sequenced, the hunt is on to find the genetic changes that led to the evolution of our own species, Homo sapiens. Researchers have recently found genes that may have endowed humans with larger brains and the ability to speak. Now a research group has uncovered evidence that another gene may have given the brains of apes, including humans, a major cognitive boost millions of years ago. The gene, called GLUD2, encodes glutamate dehydrogenase (GDH)--an enzyme that helps recycle one of the brain's most important neurotransmitters, glutamate. But there are actually two types of GDH: the one coded by GLUD2, which is found mostly in nerve tissues, and a second type, coded by a gene called GLUD1, which is found in many different cells and performs a variety of functions. In a paper published online on 19 September in Nature Genetics, Fabien Burki and Henrik Kaessmann, two genome researchers at the University of Lausanne in Switzerland, report that the brain-specific gene, GLUD2, is found only in apes and humans but not in Old World Monkeys, which only have GLUD1. Moreover, after the ape-human and Old World monkey lineages went their separate evolutionary ways about 23 million years ago, GLUD2 underwent a number of changes that may have enhanced its ability to recycle glutamate. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Evolution; Intelligence
Link ID: 6136 - Posted: 06.24.2010

CHARLOTTESVILLE, Va. -- Elderly men who are sedentary or walk less than a quarter of a mile per day are nearly twice as likely to develop dementia and Alzheimer's disease compared to men who walk more than two miles per day, according to a study of over 2,200 Japanese-American men in Hawaii. The study is published in the Sept. 22 issue of the Journal of the American Medical Association. "This is additional evidence that exercise includes health benefits other than just lowering the risk for coronary disease, cancer and other diseases. We now have evidence that regular walking is also associated with benefits that are related to cognitive function later in life," said Robert D. Abbott, Ph.D., professor of biostatistics at the University of Virginia Health System and a co-author of the study. Dementia is a chronic, or persistent, disorder of mental processes due to brain disease. Symptoms may include personality changes, as well as losses in reasoning, orientation, and memory, that interfere with a person's usual activities. So far, it is not clear why walking seems to protect the aging brain from dementia and Alzheimer's disease. "If you've been active throughout your life it could have direct relationships with the same kind of healthy risk factors that are often associated with less obesity, diabetes and heart disease," Abbott said. "People who are active tend to adhere to a healthier life-style and a better diet than those who are inactive. All of these factors could be working together in determining overall vitality and how healthy our brain is. There is also the possibility that people who walk are less likely to get diseases later on in life that could lead to dementia versus people who are inactive."

Keyword: Alzheimers
Link ID: 6135 - Posted: 09.22.2004

Newsweek - Every evening our eyes tell us that the sun sets, while we know that, in fact, the Earth is turning us away from it. Astronomy taught us centuries ago that common sense is not a reliable guide to reality. Today it is neuroscience that is forcing us to readjust our intuitions. People naturally believe in the Ghost in the Machine: that we have bodies made of matter and spirits made of an ethereal something. Yes, people acknowledge that the brain is involved in mental life. But they still think of it as a pocket PC for the soul, managing information at the behest of a ghostly user. Modern neuroscience has shown that there is no user. "The soul" is, in fact, the information-processing activity of the brain. New imaging techniques have tied every thought and emotion to neural activity. And any change to the brain—from strokes, drugs, electricity or surgery—will literally change your mind. But this understanding hasn't penetrated the conventional wisdom. We tell people to "use their brains," we speculate about brain transplants (which really should be called body transplants) and we express astonishment that meditation, education and psycho-therapy can actually change the brain. How else could they work? This resistance is not surprising. In "Descartes' Baby," psychologist Paul Bloom argues that a mind-body distinction is built into the very way we think. Children easily accept stories in which a person changes from a frog to a prince, or leaves the body to go where the wild things are. And though kids know the brain is useful for thinking, they deny that it makes them feel sad or love their siblings. © 2004 Newsweek, Inc.

Keyword: Development of the Brain
Link ID: 6134 - Posted: 06.24.2010

By Judy Skatssoon, ABC Science Online — A study of how the size of snakes' heads change in response to the size of their prey has cast new light on the nature versus nurture debate. An Australian and French study has showed that adaptability is a combination of genes and life experiences. Research published in the latest issue of the journal Nature described a study of two separate populations of tiger snakes (Notechis scutatus). The mainland population, found at Herdsman Lake in Western Australia, ate frogs and mice, and had small jaws. The second population, on Carnac Island off the coast of Western Australia southwest of Fremantle, preyed on silver-gull chicks and had larger heads. A team including the University of Sydney's Richard Shine tested whether the different head sizes were the result of genetic mutations or a lifetime physical adaptation to the environment, known as adaptive developmental plasticity. "There's been a scarcity of good examples of how these sorts of different ways of adapting to a challenge fit together," Shine said. Copyright © 2004 Discovery Communications Inc.

Keyword: Evolution
Link ID: 6133 - Posted: 06.24.2010

BY JAMIE TALAN Scientists at Brookhaven National Laboratory have identified a biochemical abnormality that might help explain why some people with AIDS develop dementia. For the first time in living AIDS patients with early signs of dementia, scientists detected depletion of the brain chemical dopamine. Not everyone with AIDS develops dementia. It is more common in the late stages of AIDS. Depletion of dopa- mine is most often associated with Parkinson's, not dementia. Brain scan studies suggest that AIDS patients with dementia have lost between 12 to 20 percent of their dopamine cells. By contrast, Parkinson's patients lose 80 to 90 percent of the dopamine cells in a key area of the brain that regulates movement before any symptoms develop. In addition to the tremors and rigidity, many Parkinson's patients can also suffer mild attention and thinking problems and are at high risk for depression. Copyright © 2004, Newsday, Inc.

Keyword: Alzheimers
Link ID: 6132 - Posted: 06.24.2010

Researchers have combined sophisticated biochemical and imaging techniques to get a glimpse of the stepwise assembly of amyloid fibers in a yeast prion protein. Their findings suggest that these structured fibers form in competition with the amorphous globules that some believe may cause toxicity in amyloid diseases such as Alzheimer's and Parkinson's. The researchers say this may have important implications for those designing drugs to prevent formation of the brain-damaging proteins in those diseases. The researchers reported their findings in the October 2004 issue of the Public Library of Science Biology. They were led by Howard Hughes Medical Institute investigator Jonathan S. Weissman at the University of California, San Francisco. HHMI investigator Ronald D. Vale, also of UCSF, was a co-author of the article. Working in yeast, Weissman and his colleagues investigated the mechanism by which a prion protein assembles individual polypeptides into long amyloid fibers. These fibers are similar to the amyloid plaques that clog the brains of patients with Alzheimer's or Parkinson's disease. © 2004 Howard Hughes Medical Institute.

Keyword: Alzheimers
Link ID: 6131 - Posted: 06.24.2010

Helen Pilcher An unusually powerful magnetic resonance imaging (MRI) machine was unveiled today that should reveal not just the anatomy but also the metabolism of the human brain, say scientists at the University of Illinois at Chicago. If it lives up to its promise, the machine should help researchers to probe how the brain thinks, learns, fights disease and responds to experimental therapies. But it will involve exposing patients to stronger magnetic fields than ever before. MRI uses a combination of magnetism, radio waves and computing power to peer inside the body. Patients lie inside a large circular magnet. When turned on, the magnetic field causes the nuclei of certain atoms, including hydrogen, to line up. A pulse of radio waves is then sent through the magnetic field. The aligned nuclei absorb this radiation and emit it again, producing a signal that reveals the structure of the molecules in which the atoms sit. Most MRI machines use magnets with field strengths of around 3 tesla (equivalent to around 30 fridge magnets). This allows researchers to image water molecules and create pictures of anatomical structures within the body. ©2004 Nature Publishing Group

Keyword: Brain imaging
Link ID: 6130 - Posted: 06.24.2010