Scientists discover that some brains age more rapidly than others; noticed change after age 40 Unraveling the mysteries of the aging brain is a major goal for brain science, especially given the exploding population of senior citizens and the obvious desire to preserve brain function as long as possible. Now, researchers at Children's Hospital Boston and Harvard Medical School have uncovered a kind of genetic signature associated with the aging human brain that may contribute to cognitive decline associated with aging. The study appears June 9 as an advance on-line publication of the journal Nature. One of the study's more surprising results was that these gene changes start in the 40s for some individuals. The results raise intriguing questions about when and why the brain begins to age and the possibility of developing strategies to protect critical genes early in life in an attempt to preserve brain function and delay the onset of age-related conditions such as Alzheimer's disease. To investigate age-associated molecular changes in the human brain, Dr. Bruce A. Yankner, professor in the Department of Neurology and Division of Neuroscience at Children's Hospital Boston and Harvard Medical School, and colleagues examined patterns of gene expression in postmortem samples collected from thirty individuals ranging in age from 26 to 106 years.

Keyword: Genes & Behavior
Link ID: 5629 - Posted: 06.10.2004

The biological clocks that control the daily lives of every living thing Russell Foster and Leon Kreitzman We are all fascinated with rhythms: repetitive patterns in art, vibrations of a cello string, waves of water and sand, and all sorts of similar regularities in living organisms such as zebra stripes and the segments of a worm. Many of these involve time either directly (as in a cello string or ocean waves) or at the moment of their formation (as in animal stripes and segments). Rhythms of Life is about biological rhythms that involve time exclusively: heartbeats, daily rhythms in particular, as well as monthly ones, annual ones, and even those that span many years. Russell Foster and Leon Kreitzman are experts in the field of biological clocks and, with great skill, give us an up-to-date and readable account of what we know today about the time cycles that affect the majority of all living organisms, including ourselves. They tell us the basis of jet lag, how our clocks affect our sleeping, and why there is a best time to take certain pills so that they are maximally effective. To see what underlies these human phenomena, they give us a picture of the whole field for a better understanding of the basis of all biological rhythms. In doing so they convincingly make it evident that the basic phenomenon of time cycles in living organisms is in itself a fascinating subject. ©2004 THE TLS

Keyword: Biological Rhythms
Link ID: 5628 - Posted: 06.24.2010

DURHAM, N.C. -- If the emotional memory of a traumatic car accident or the thrill of first love are remembered with a special resonance, it is because they engage different brain structures than do normal memories, Duke University researchers have discovered. Their new study provides clear evidence from humans that the brain's emotional center, called the amygdala, interacts with memory-related brain regions during the formation of emotional memories, perhaps to give such memories their indelible emotional resonance. The researchers said their basic insights could contribute to understanding of the role that the neural mechanisms underlying emotional memory formation play in post traumatic stress disorder and depression. According to Florin Dolcos, in their experiments the researchers were seeking evidence for the "modulation hypothesis," which holds that the brain's emotional and memory centers interact during the formation of emotional memories.

Keyword: Emotions; Learning & Memory
Link ID: 5627 - Posted: 06.10.2004

Since one of the basic risk factors for alcoholism is a tolerance to alcohol, researchers have long sought to understand the genetic differences among people that affect their sensitivity to alcohol. So far, scientists have met with little success. However, by exposing populations of the roundworm C. elegans to alcohol and pinpointing subtle genetic differences among strains that respond differently, researchers have identified one gene that affects alcohol sensitivity. In an article in the June 10, 2004, issue of Neuron, Andrew Davies and his colleagues describe their findings that subtle differences between worm strains in the gene for a brain protein called NPR-1 explains differences in the worms' alcohol sensitivity. The researchers chose the worm as their subject because there is evidence that alcohol has effects on worm behavior. Although the mechanisms that mediate alcohol response in humans or other animals are not well understood, most human neuronal proteins have worm versions and it seems likely that at least some of the mechanisms are shared. Additionally, the worm has been the subject of massive genetic study by scientists, and genetically distinct strains are available from around the world.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 5626 - Posted: 06.10.2004

— Howard Hughes Medical Institute (HHMI) researchers have made the surprising discovery that people with Alzheimer's disease retain the capability for a specific form of memory used for rote learning of skills, even as their memories of people and events are extinguished. The scientists' discovery suggests new strategies to improve training and rehabilitative programs that may bolster the retained cognitive function of those with Alzheimer's disease as well as healthy older people. “From this and other studies we have done, it appears that a number of brain systems are more intact in Alzheimer's than we had anticipated,” said Howard Hughes Medical Institute researcher Randy L. Buckner at Washington University in St. Louis. “The findings suggest that if we can help people use these brain systems optimally by providing the right kinds of cues or task instructions, we may be able to improve their function.” In an article published in the June 10, 2004, issue of the journal Neuron, Buckner and Cindy Lustig, also at Washington University, compared implicit memory capabilities in young adults, healthy older adults and those in the early stages of Alzheimer's disease. ©2004 Howard Hughes Medical Institute

Keyword: Alzheimers; Learning & Memory
Link ID: 5625 - Posted: 06.24.2010

Women are significantly more likely to have sex during the fertile part of their monthly cycle, suggests new research. "If you're a couple trying to get pregnant, that's great news. There's a hidden biological process working in your favour," says Allen Wilcox, a reproductive epidemiologist at the US National Institute of Environmental Health Sciences in Durham, North Carolina, and lead researcher of the study. "If you are not trying to pregnant the news is not so good," he told New Scientist. The work indicates that having unprotected sex once is more likely to result in pregnancy than previously thought. The underlying reason for the coincidence of intercourse and heightened fertility is not clear. Previous research suggests women feel sexier in the days before ovulation, which may increase their own libido or make them more attractive to their partners. And men have been found to be more attentive to their female partners around ovulation. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 5624 - Posted: 06.24.2010

By Tony Fitzpatrick That's using your brain. For the first time in humans, a team headed by researchers at Washington University in St. Louis has placed an electronic grid atop patients' brains to gather motor signals that enable patients to play a computer game using only the signals from their brains. The use of a grid atop the brain to record brain surface signals is a brain-machine interface technique that uses electrocorticographic (ECoG) activity-data taken invasively right from the brain surface. It is an alternative to the status quo, used frequently studying humans, called electroencephalographic activity (EEG) - data taken non-invasively by electrodes outside the brain on the skull. The breakthrough is a step toward building biomedical devices that can control artificial limbs, some day, for instance, enabling the disabled to move a prosthetic arm or leg by thinking about it. The study was published in the June 8, 2004 issue of the Journal of Neural Engineering and was partially funded by the National Institutes of Health (NIH).

Keyword: Robotics
Link ID: 5623 - Posted: 06.10.2004

Scan shows how we form opinions. TANGUY CHOUARD Researchers may have pinpointed the brain regions that help us work out good from bad. And their results suggest that humans and robots are more alike than we may care to admit, as both use similar strategies to make value judgements. Ben Seymour from University College London and colleagues used a functional magnetic resonance imaging scanner to study the brain activity of 14 people as they learned to distinguish a bad hunch from a good omen. Subjects were shown arbitrary images and certain combinations were followed by a painful electrical shock delivered to the back of the hand, whereas others prompted a less painful jolt. After a few trials, subjects were subconsciously able to predict the arrangements that spelled trouble. As they learned, key regions of their brain lit up. The research is published in this week's Nature1. One illuminated area, the insula cortex, helps to process emotions. Another, known as the ventral striatum, is well known as the brain's motivation centre. But this is the first time they have been implicated in the ability to learn good from bad. © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Robotics; Emotions
Link ID: 5622 - Posted: 06.24.2010

Out of sight By Gila Z. Reckess — Pointing at an object may not seem complicated, but even such a simple act requires an intricate network of brain activity. Scientists traditionally thought this network included a one-way "information highway" between the brain's visual system and its motor and sensory systems, but research at Washington University School of Medicine in St. Louis now challenges this long-held theory. The study presents surprising evidence that the brain's visual system is not only responsible for seeing, or perceiving, objects outside the body, but also is involved when individuals sense and manipulate their own bodies. Such insight may help scientists understand puzzling disorders like anosognosia, which is characterized by unusual perceptual experiences. For example, individuals with this disorder may not recognize their arms as part of their own bodies. "Vision apparently is far more complicated and integrated than we suspected," says Maurizio Corbetta, M.D., associate professor of neurology, of radiology and of anatomy and neurobiology. "Areas thought to be exclusively involved in perceiving the world around us apparently also are involved in integrating visual, spatial and sensory-motor signals to help each of us develop an internal representation of our body and its position in space."

Keyword: Vision
Link ID: 5621 - Posted: 06.24.2010

By STEVE DITLEA Craaackle! Craaackle! In a small operating room at Beth Israel Hospital on Manhattan's upper East Side, it sounds like someone is making popcorn. Amplified over a speaker, it's actually the sound of one brain cell firing, picked up by an electrode, no thicker than a hair, being threaded deep into a man's brain. The brain belongs to 54-year-old Paul Luskin, who suffers from Parkinson's disease. For four years he's been walking around with a pacemaker-size computer linked to his brain. The device delivers an electrical pulse to suppress the faulty nerve signals that cause his tremors, muscular stiffness and speech difficulties. But lately the symptoms on his left side have worsened, forcing him to retire from his career as a tour organizer. He is now seeking relief with a second brain implant and another computerized pacemaker in his chest, further advancing the treatment known as deep-brain stimulation. Luskin is one of several hundred New Yorkers who since the turn of the 21st century have become figures seemingly out of science fiction: they are cyborgs (an abbreviation of "cybernetic organism," a NASA-coined term that describes a person whose physiological functioning is aided by, or dependent on, a mechanical or electronic device.) All contents © 2004 Daily News, L.P.

Keyword: Parkinsons; Movement Disorders
Link ID: 5620 - Posted: 06.24.2010

Christopher R. Brodie Superman has super-hearing. Spider-Man has an uncanny "spider sense." But truth can be stranger than fiction. The newest superhero doesn't wear a cape or mask. It's a mouse, and it looks just like its normal brethren. Its super power is its amazing … nose. In a paper published in the February 5 issue of Neuron, collaborators at Florida State University and Yale University describe what they call "super-smeller" mice. These exceptional creatures have noses that are 1,000 to 10,000 times more sensitive than those of ordinary mice. The superhero origin of these rodents involves the deletion, or knockout, of a gene. This technique usually generates mice that are quite sick, as nearly all mutations are harmful. Yet it doesn't seem to be true for this gene, Kv1.3, which encodes a protein that acts as a channel to let potassium ions (K+) into cells. This particular ion channel is found in immunological T-cells and neurons in the hippocampus and the olfactory bulb—the part of the brain that gets information from odor receptors in the nose. In neurons, K+ channels such as Kv1.3 can act like governors on an engine, restricting the firing rate of the electrical spikes known as action potentials. The deletion of Kv1.3 removes this block. Using mice generated in the Yale lab of Richard Flavell, a team at Florida State led by Debra Fadool discovered that the loss of the channel caused one type of olfactory neuron, the mitral cell, to fire at lower thresholds and higher frequencies. © Sigma Xi, The Scientific Research Society

Keyword: Chemical Senses (Smell & Taste)
Link ID: 5619 - Posted: 06.24.2010

A drug made from an extract of cannabis has helped to reduce the pain caused by rheumatoid arthritis. The drug, Sativex, has been developed by GW Pharmaceuticals, which is assessing the medical benefits of cannabis under a government licence. Tests of a spray form of the drug on 58 arthritis patients showed it helped reduce pain, and improve quality of sleep. Few people showed signs of side effects, the company said. GW Pharmaceuticals has previously carried out trials showing that Sativex can reduce the pain associated with multiple sclerosis. Dr Philip Robson, director of GW's Cannabinoid Research Institute, said: "These results are particularly exciting because this is the first ever controlled clinical trial of a cannabis-based medicine in the treatment of arthritis. "To date, GW's research has concentrated on multiple sclerosis and neuropathic pain and it is therefore very encouraging to see these positive effects of Sativex on pain and other symptoms of rheumatoid arthritis. (C)BBC

Keyword: Drug Abuse; Pain & Touch
Link ID: 5618 - Posted: 06.09.2004

Some people may be genetically programmed to be unfaithful to their partner, a scientist has claimed. Professor Tim Spector, of the Twin Research Unit at St Thomas' Hospital, London, says he has evidence of a genetic component to infidelity. Focusing on women, he found that if one of a pair of twins had a history of infidelity, the chances her sister would also stray were about 55%. In general it is estimated that just 23% of women are not faithful. In addition, Professor Spector found the tendency for both twins to be either faithful or unfaithful was strongest in identical pairs - who have identical genes. He stressed that genes alone did not determine whether somebody was likely to be unfaithful - much was down to social factors. But he said it made good sense in evolutionary terms to get a good mix of genes - and for women to choose a better option if one came along.

Keyword: Genes & Behavior; Sexual Behavior
Link ID: 5617 - Posted: 06.09.2004

When Ronald Reagan announced in 1994 that he was suffering from Alzheimer's, he became a prominent face of a disease which afflicts about 4.5 million Americans. Like many Alzheimer's patients, Reagan lived a long time with the disease; a person with Alzheimer's will live an average of eight years and as many as 20 years or more from the onset of symptoms, as estimated by relatives. Reagan lost his battle with Alzheimer's on Saturday, June 5, after ten years of suffering from the debilitating effects of the disease. Today, we're still not sure what causes it. "We think Alzheimer's has several causes, although the actual cause is unknown," says Paul Thompson of the UCLA Laboratory for Neuroimaging. "You might be at genetic risk for it, or there might be different chemicals in the body that actually control your risk for getting Alzheimer's." Researchers have theorized that fibrous masses of protein in the brain play a role in Alzheimer's disease. Called amyloids, these plaques block nerve communication. What's more, scientists have had trouble finding a way to dissolving these plaques once they form. "They're so tough," says Susan Lindquist, director of the Whitehead Institute for Biomedical Research. "They're resistant to detergents, they're resistant to salt, they're resistant to freezing or boiling, they're resistant to organic solvents, even." © ScienCentral, 2000-2004.

Keyword: Alzheimers
Link ID: 5616 - Posted: 06.24.2010

In the brain, nerve cells, or neurons, grow new connections, which resemble branches on a tree. These branches send and receive signals, and their growth is vital to normal brain function; the more branches there are, the more sites by which a neuron can send and receive information. "While you're an adult, your brain doesn't just stop growing and doesn't just stop making new connections. It actually forms new connections all the time," says Bonnie Firestein, professor of cell biology and neuroscience at Rutgers University. "We know that when you're learning something, you have new connections made. So, the brain is constantly growing and constantly changing." Firestein has found that a brain chemical called cypin helps nerve cells sprout new branches of communication, and the more cypin you have, the more branches you have. "We know that if you decrease cypin, in our system, you have a lower amount of branches," she explains. "So, right now…we just know that cypin is really important for making the correct number of branches, and that if you increase cypin you get more branches, and that it's been shown that more branches generally corresponds to learning and memory. When you're learning, you're making the nerve cells active, you're having increases in cypin, and then you're having more branches or more wiring so that you can learn." © ScienCentral, 2000-2004.

Keyword: Development of the Brain
Link ID: 5615 - Posted: 06.24.2010

Would you know what species to mate with if you'd grown up alone and didn't have a mirror? That's the challenge faced by the Australian brush turkey, which hatches alone in a warm mound of rotting leaf litter. Now, with the help of remote-control robots made from toy car motors and the skins of dead chicks, a research team has gleaned the first insights into how the brush turkey recognizes its own kind. Most birds learn to identify their own species by "imprinting" on their parents while their nervous system is still at an impressionable stage, but for brush turkeys (family Megapodiidae) that's not an option. Females lay eggs in a compost heap built by the male, then leave the incubation up to the heat from decomposition. That means the chicks can't imprint. "It's the most nonavian life history you can get among creatures that are still feathered and lay hard-shelled eggs," notes Mark Hauber, a behavioral ecologist at the University of Auckland in New Zealand. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior; Development of the Brain
Link ID: 5614 - Posted: 06.24.2010

By Mari N. Jensen When algae find themselves in hot water, the normally asexual organisms get all stressed out and turn sexual. Blame it on the free radicals, says a team of researchers. Colonies of the multicellular green alga Volvox carteri exposed to temperatures of 111 degrees Fahrenheit (42.5 degrees Celsius) had twice the amount of free radicals, oxidants that can damage biological structures, as unheated colonies. High levels of oxidants within their cells activated the algae's sex-inducer gene, the researchers report. Then the fun starts. The sex-inducer gene promotes the production of the sex-inducer, a pheromone the colony releases to guarantee willing mating partners. "We're the first to show that oxidants are responsible for sex in this organism," said UA professor Richard E. Michod, head of UA's department of ecology and evolutionary biology and a coauthor on the research. "This is the first demonstration that stress turns on sex-inducer genes." © 2004 Arizona Board of Regents

Keyword: Sexual Behavior; Evolution
Link ID: 5613 - Posted: 06.24.2010

A new study indicates that postnatal exposure to thimerosal, a mercury preservative commonly used in a number of childhood vaccines, can lead to the development of autism-like damage in autoimmune disease susceptible mice. This animal model, the first to show that the administration of low-dose ethylmercury can lead to behavioral and neurological changes in the developing brain, reinforces previous studies showing that a genetic predisposition affects risk in combination with certain environmental triggers. The study was conducted by researchers at the Jerome L. and Dawn Greene Infectious Disease Laboratory at the Mailman School of Public Health, Columbia University. Over the past 20 years, there has been a striking increase--at least ten-fold since 1985--in the number of children diagnosed with autism spectrum disorders. Genetic factors alone cannot account for this rise in prevalence. Researchers at the Mailman School, led by Dr. Mady Hornig, created an animal model to explore the relationship between thimerosal (ethylmercury) and autism, hypothesizing that the combination of genetic susceptibility and environmental exposure to mercury in childhood vaccines may cause neurotoxicity. Cumulative mercury burden through other sources, including in utero exposures to mercury in fish or vaccines, may also lead to damage in susceptible hosts. Timing and quantity of thimerosal dosing for the mouse model were developed using the U.S. immunization schedule for children, with doses calculated for mice based on 10th percentile weight of U.S. boys at age two, four, six, and twelve months.

Keyword: Autism
Link ID: 5612 - Posted: 06.09.2004

Gene therapy succeeds in mice with brain disease. ERIKA CHECK Gene therapy could ease the symptoms of some devastating brain disorders, according to evidence presented to US conference last week. Many neurodegenerative diseases are caused when the brain makes mutant proteins that build up in the brain, causing gradually worsening symptoms. These brain-wasting diseases are devastating and incurable. They include Huntington’s disease, which affects around 250,000 people in the United States. Beverley Davidson of the University of Iowa in Iowa City and her colleagues hope that gene therapy will help treat such diseases. The approach involves trying to correct genetic abnormalities by injecting an animal or person with corrective sequences of DNA or RNA. The researchers tested their therapy in mice with a disorder that mimics a disease called spinocerebellar ataxia type 1, which leaves sufferers progressively less able to walk. The therapy eliminated pockets of damaged brain tissue from the mice and corrected the physical symptoms of the disease. © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Huntingtons
Link ID: 5611 - Posted: 06.24.2010

— Muscular dystrophy is a group of genetic diseases characterized by progressive muscle degeneration. Working with mice with a type of the disease, researchers have found that by expressing an enzyme that attaches sugar molecules to a protein essential for proper muscle structure, they can restore normal muscle function. Interestingly, the scientists found evidence of similar benefits when they expressed the protein, known as LARGE, in cells from patients with similar types of muscular dystrophies with distinct gene defects, suggesting that this approach may have clinical benefits for patients with the debilitating disease. The study, led by Howard Hughes Medical Institute investigator Kevin P. Campbell at the University of Iowa College of Medicine, was published online in the journal Nature Medicine on June 6, 2004. Campbell's co-authors on the paper were from the University of Iowa, the University of Toronto, Uppsala University in Sweden, and the National Center of Neurology and Psychiatry in Tokyo. The study complements additional work by Campbell and colleagues from the Scripps Research Institute in California, the California Pacific Medical Center Research Institute, and Uppsala University, which elucidated the critical role of LARGE in the processing of a protein required to link muscle cells to their surrounding matrix. This work was published in an advance online publication of Cell on June 3, 2004. ©2004 Howard Hughes Medical Institute

Keyword: Muscles; Movement Disorders
Link ID: 5610 - Posted: 06.24.2010