The octopus arm is extremely flexible. Thanks to this flexibility--the arm is said to possess a virtually infinite number of "degrees of freedom"--the octopus is able to generate a vast repertoire of movements that is unmatched by the human arm. Nonetheless, despite the huge evolutionary gap and morphological differences between the octopus and vertebrates, the octopus arm acts much like a three-jointed vertebrate limb when the octopus performs precise point-to-point movements. Researchers have now illuminated how octopus arms are able to form joint-like structures, and how the movements of these joints are controlled. The new findings, which appear in the April 18th issue of Current Biology, are reported by Tamar Flash of the Weizmann Institute of Science, Binyamin Hochner and German Sumbre of Hebrew University, and Graziano Fiorito of the Stazione Zoologica di Napoli. The extreme motility of the octopus arm demands a highly complex motor control system. Past work from Dr. Hochner's group showed that when retrieving food to its mouth, the octopus actually shapes its arm into a quasi-articulated structure by forming three bends that act like skeletal joints. This puts an artificial constraint of sorts on the arm's movement and simplifies the otherwise complex control of movement that would be needed for the arm to fetch food from a distant point to the octopus's mouth. In the new work, the researchers sought to identify how the octopus manages to transform its extremely flexible arm into a structure that acts like a jointed appendage.

Keyword: Miscellaneous
Link ID: 8790 - Posted: 04.18.2006

Researchers supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH), have identified new genes that may contribute to excessive alcohol consumption. The new study, conducted with strains of animals that have either a high or low innate preference for alcohol, provides clues about the molecular mechanisms that underlie the tendency to drink heavily. A report of the findings appears in the April 18, 2006 issue of Proceedings of the National Academy of Sciences. “These findings provide a wealth of new insights into the molecular determinants of excessive drinking, which could lead to a better understanding of alcoholism,” notes NIAAA Director Ting-Kai Li, M.D. “They also underscore the value that animal models bring to the investigation of complex human disorders such as alcohol dependence.” Mice that have been selectively bred to have either a high or low preference for alcohol have been a mainstay of alcohol research for many years, allowing investigators to study diverse behavioral and physiological characteristics of alcohol dependence. In the current study, NIAAA grantee Susan E. Bergeson, Ph.D., of the University of Texas (UT) at Austin, and a multi-site team of scientists participating in NIAAA’s Integrative Neuroscience Initiative on Alcoholism (INIA) used microarray techniques to study gene expression in the brains of these animals. Microarrays are powerful tools that investigators use for comprehensive analyses of gene activity.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8789 - Posted: 06.24.2010

By Tracy Staedter, Discovery News — A computerized typewriter that translates electrical impulses from brainwave signals into letters and words could be available in the next five years. In the short term, the technology will allow its developers, from the Fraunhofer Institute and the Charité Hospital in Berlin, Germany, to watch a thinking and behaving brain function in real time. But in the long term, such a brain-machine interface could replace the joystick in electronic gaming or serve as a communication tool for people unable to speak or sign. "We are dreaming of something like a baseball cap with electrodes in the cap that can measure the brainwaves," said one of the scientists behind the project, Klaus-Robert Mueller of the Fraunhofer Institute. "People could just put on the cap and have a wireless connection from these electrodes to a computer and they can play video games." That vision, said Mueller, will require advances in electrode technology that allow the tiny, metal sensors to pick up electric signals from brainwave activity without making contact with the skin. © 2006 Discovery Communications Inc.

Keyword: Robotics
Link ID: 8788 - Posted: 06.24.2010

By Victor Limjoco With swelling prison populations, researchers are trying to understand the biology behind aggressive behavior. National Institute of Mental Health scientist Andreas Meyer-Lindenberg is looking for clues to how genes wire our brains early in life. "One of the most fascinating things," Meyer-Lindenberg says, about this field of science called psychiatric genetics, "is how it is possible that genes [can] encode for molecules that affect something as complex as behavior, even psychiatric illness such as depression and social behavior." He's focusing on a specific gene that was previously linked to impulsive violence in certain populations of people. A study in 2002 found that subjects with a particular form of a gene had a significantly higher risk of violence, but only in certain populations. Genes can affect complex behaviors like aggression, because they direct the production of proteins - the building blocks of living systems. Certain types of proteins, called enzymes, break down chemicals in the brain, most notably, serotonin - a chemical messenger in the brain that helps brains cells communicate to each other. To isolate how a variation in this gene, called MAOAG, might affect the wiring of the brain, Meyer-Lindenberg took MRI brain scans of more than 100 healthy volunteers. Since this genetic variation is common in our population, some of the volunteers had this variation, and some didn't. © 2005 Discover Media LLC.

Keyword: Aggression; Genes & Behavior
Link ID: 8787 - Posted: 06.24.2010

By STEPHEN MIHM Most prisons are notorious for the quality of their cuisine (pretty poor) and the behavior of their residents (pretty violent). They are therefore ideal locations to test a novel hypothesis: that violent aggression is largely a product of poor nutrition. Toward that end, researchers are studying whether inmates become less violent when put on a diet rich in vitamins and in the fatty acids found in seafood. Could a salmon steak and a side of spinach really help curb violence, not just in prison but everywhere? In 2001, Dr. Joseph Hibbeln, a senior clinical investigator at the National Institutes of Health, published a study, provocatively titled "Seafood Consumption and Homicide Mortality," that found a correlation between a higher intake of omega-3 fatty acids (most often obtained from fish) and lower murder rates. Of course, seeing a correlation between fatty acids and nonviolence doesn't necessarily prove that fatty acids inhibit violence. Bernard Gesch, a senior research scientist at Oxford University, set out to show that better nutrition does, in fact, decrease violence. He enrolled 231 volunteers at a British prison in his study; one-half received a placebo, while the other half received fatty acids and other supplements. Over time, the antisocial behavior (as measured by assaults and other violations) of the inmates who had been given the supplements dropped by more than a third relative to their previous records. The control group showed little change. Gesch published his results in 2002 and plans to start a larger study later this year. Similar trials are already under way in Holland and Norway. Copyright 2006 The New York Times Company

Keyword: Aggression
Link ID: 8786 - Posted: 04.17.2006

Washington -- Neuroscientists at Harvard Medical School and its affiliate Mclean Hospital have shown that long-term exposure to stress hormone in mice directly results in the anxiety that often comes with depression. After years of circumstantial evidence linking stress and depression, this evidence may be the "smoking gun" of what, for some, causes some types of mood disorders. The research appears in the April issue of Behavioral Neuroscience, which is published by the American Psychological Association. The findings are important for understanding the causes and improving the treatment of depression. Scientists already knew that many people with depression have high levels of cortisol, a human stress hormone, but it wasn't clear whether that was a cause or effect. Now it appears likely that long-term exposure to cortisol actually contributes to the symptoms of depression. Paul Ardayfio, PhD candidate, and Kwang-Soo Kim, PhD, made their discovery by exposing mice to both short-term and long-term durations of stress hormone, which in rodents is corticosterone. In humans, usually ongoing, chronic stress, such as caring for a spouse with dementia, rather than acute stress, has been associated with depression. Using 58 mice, the researchers gave the hormone in drinking water so as not to confound the results with the stress of injection. Chronic doses were 17 to 18 days of exposure; acute doses were 24 hours of exposure.

Keyword: Stress; Emotions
Link ID: 8785 - Posted: 04.17.2006

Bruce Bower Scientists working in Ethiopia's Middle Awash valley have uncovered fossils of a 4.1-million-year-old human ancestor that bolster the controversial proposition that early members of our evolutionary family evolved one at a time on a single lineage rather than branching out into numerous species. A team led by anthropologist Tim D. White of the University of California, Berkeley unearthed 31 fossils of Australopithecus anamensis, the earliest known species of this ancient hominid genus. The finds, from at least eight individuals, consist primarily of teeth and jaws, but include foot and hand bones and much of an upper right-leg bone. Anatomical similarities indicate that Au. anamensis evolved directly from an earlier hominid, Ardipithecus ramidus (SN: 1/22/05, p. 51: Available to subscribers at http://www.sciencenews.org/articles/20050122/fob2.asp), between 4.4 million and 4.1 million years ago, the researchers assert in the April 13 Nature. By 3.6 million years ago, they add, Au. anamensis had evolved into Australopithecus afarensis, the species that includes the partial skeleton known as Lucy. "There may have been times when one early hominid species evolved into another one without branching off into multiple species," White says. His view contrasts with that of researchers who suspect that hominids branched into many species over the past 6 million to 7 million years (SN: 5/3/03, p. 275: Available to subscribers at http://www.sciencenews.org/articles/20030503/fob1.asp). Copyright ©2006 Science Service.

Keyword: Evolution
Link ID: 8784 - Posted: 06.24.2010

After an article on the topic elicited a strong response from readers, Scientific American Mind magazine conducted a nationwide Zogby Interactive poll that found that 50 percent of Americans believe sexual orientation is not a choice, while only 11 percent said it is a conscious choice. Thirty-four percent believe it's a combination of both. The idea that sexual preference is a hard-wired part of who we are is consistent with a growing body of scientific research that indicates a biological basis for sexual orientation, including studies of identical twins, studies of other species that don't have cultural influences, and the discovery of genes that can change the sexual behavior in flies. But, as psychiatrist Jack Drescher says, "the clinical question has gotten caught up in this whole political argument." At the heart of the controversy is Columbia University psychiatrist Robert Spitzer. In 1973, he helped to get homosexuality removed from psychiatry's official classification manual of mental illnesses, the Diagnostic and Statistical Manual of Mental Disorders. But 30 years later, in 2003, he interviewed 200 people who claimed to have changed from gay to straight, and published the study concluding that such change is possible. © ScienCentral, 2000-2006.

Keyword: Sexual Behavior
Link ID: 8783 - Posted: 06.24.2010

By Greg Miller SAN FRANCISCO--The summer Olympics only come around every four years, and for elite athletes vying for a spot on their national teams, failure to qualify can be crushing. Now, researchers have taken a look at how the brain deals with dashed Olympic dreams. Their findings hint at a possible explanation for why athletes who've suffered tough losses often have a hard time getting back on top of their game. It's a frustrating problem for both athletes and sports psychologists, says Hap Davis, a Canadian psychologist based in Calgary. "You can get people feeling good again, but they don't perform at the level they need to," he says. To get a peek inside his patients' heads, Davis teamed up with cognitive neuroscientists, including Mario Liotti at Simon Fraser University in Burnaby, Canada. The team used functional magnetic resonance imaging to examine the brains of 14 swimmers, 10 women and four men, who didn't make the 2004 Canadian Olympic team. Inside the scanner, the swimmers each watched a video clip of themselves swimming their failed qualification race and another clip featuring a different swimmer. Not surprisingly, the swimmers rated their own videos more wrenching to watch. And their brains showed signs of their emotional pain, with heightened activity in the parahippocampus and other emotion-related areas that have been implicated in depression. (None of the swimmers had a prior history of depression). © 2006 American Association for the Advancement of Science.

Keyword: Emotions
Link ID: 8782 - Posted: 06.24.2010

Johns Hopkins researchers have discovered a gene in fruit flies that helps certain specialized neurons respond more quickly to bright light. The study, published in the April 4 issue of Current Biology, also has implications for understanding sensory perception in mammals. In teasing apart the molecular interactions and physiology underlying light perception, the researchers studied a gene they dubbed “Lazaro” that is expressed 15 times higher in the fly eye than the rest of the fly head. They found that this gene is required for a second biochemical pathway that controls the activity of a protein called the TRP channel. TRP channels are found in fruit fly neurons responsible for sensing light. The fly TRP channel is the founding member of a family of related proteins in mammals that are essential for guiding certain nerves during development and for responding to stimuli including heat, taste and sound. By shining bright light onto and recording electrical changes in single nerve cells in the fly eye, researchers found that neurons carrying a mutation in this gene cannot respond as well to light as compared to neurons carrying normal copies of this gene. In fact, the mutant neurons turn off their response to light four times faster than normal neurons. Because Lazaro helps fly TRP channels work at their maximum, it is possible that a Lazaro-like gene in mammals might also play a role in how well mammalian TRP channels work.

Keyword: Vision
Link ID: 8781 - Posted: 06.24.2010

By NICHOLAS BAKALAR Women can unconsciously detect the smell of fear, new research suggests, and the smell improves their performance on mental tasks. Scientists collected sweat from seven volunteers — four men and three women — who watched horror movies while holding gauze pads in their armpits. Then, their sweat was collected while they watched videos with neutral emotional content. Sixty-eight women next performed a word-association task while smelling the pads. The task involved watching two words flash on a screen one after the other, and then stating whether the two words were related. ("Arms" and "legs" are related; "arms" and "wind" are not.) The subjects were divided into three groups: the first smelled the sweat pads of sweat collected during the frightening video; the second smelled pads collected during the neutral video; and the third, a control group, smelled pads with no sweat on them. Without sacrificing speed, the women smelling the fear pads were more accurate than those in the other two groups when processing meaningful related words. There was no difference in speed or accuracy between the three groups when the words were not related. Copyright 2006 The New York Times Company

Keyword: Chemical Senses (Smell & Taste); Emotions
Link ID: 8780 - Posted: 06.24.2010

By JOHN NOBLE WILFORD In following the fossil tracks of human evolution, scientists have for years searched for links between Australopithecus, the kin of the famous "Lucy" skeleton, and even earlier possible ancestors. Now, they think they have found some connections in Ethiopia. An international team of paleontologists is reporting the discovery of transitional species superimposed in sediments in the neighborhood of a single site. The findings appear today in the journal Nature. Tim D. White, a paleontologist at the University of California, Berkeley, who was a team leader, and his colleagues said the 4.1-million-year-old fossils were anatomically intermediate between the earlier species Ardipithecus ramidus and the later species Australopithecus afarensis, the Lucy family. The newfound bones and teeth are the earliest remains of the most primitive Australopithecus, known as anamensis. "This new discovery closes the gap between the fully blown australopithecines and earlier forms we call Ardipithecus," Dr. White said in a statement. "We now know where Australopithecus came from before four million years ago." Copyright 2006 The New York Times Company

Keyword: Evolution
Link ID: 8779 - Posted: 04.14.2006

By Michael Shermer Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease that attacks motor neurons until muscle weakness, atrophy and paralysis lead inexorably to death. Victims of this monstrous malady could be forgiven for feeling unlucky. How, then, can we explain the attitude of the disease's namesake, baseball great Lou Gehrig? He told a sellout crowd at Yankee Stadium: "For the past two weeks you have been reading about the bad break I got. Today I consider myself the luckiest man on the face of this earth." The Iron Horse then recounted his many blessings and fortunes, a list twice punctuated with "I'm lucky" and "That's something." Clearly, luck is a state of mind. Is it more than that? To explore this question scientifically, experimental psychologist Richard Wiseman created a "luck lab" at the University of Hertfordshire in England. Wiseman began by testing whether those who believe they are lucky are actually more likely to win the lottery. He recruited 700 subjects who had intended to purchase lottery tickets to complete his luck questionnaire, which is a self-report scale that measures whether people consider themselves to be lucky or unlucky. Although lucky people were twice as confident as the unlucky ones that they would win the lottery, there was no difference in winnings. © 1996-2006 Scientific American, Inc.

Keyword: Emotions
Link ID: 8778 - Posted: 06.24.2010

New Haven, Conn. -- Yale scientists have systematically plotted the responses of the entire Drosophila (fruit fly) olfactory system, providing the first multi-dimensional map of the range of odorants sensed and the regions of the brain that are stimulated. John Carlson, the Eugene Higgins Professor of Molecular, Cellular and Developmental Biology and Elissa Hallem, his former graduate student in the Interdepartmental Neuroscience Program, published the comprehensive study in the journal Cell. "The results of our analysis allow us to make predictions about which odors smell alike to an animal, and which smell different," said Carlson. "These predictions can now be tested in behavioral experiments and may help point us to insect attractants and repellants that are highly effective." This paper provides particular insight into the understanding of how animals perceive environmental smells that are often complex mixtures of molecular structures. The study identifies compounds that both stimulate and inhibit response in odor neurons, and the differences in response that are due to concentration and duration of exposure to a compound.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8777 - Posted: 04.14.2006

Comparative studies have studied testosterone levels and related them to mating systems and aggression, but very few studies have attempted to relate testosterone to fitness, that is, the combination of lifetime reproductive success and survival, in the wild or experimentally. Over nine breeding seasons, Wendy Reed (North Dakota State University) and her colleagues followed a group of dark-eyed juncos, small mountain songbirds found throughout North America. They injected males with elevated levels of testosterone and found that they had shorter lives but that they were very successful at siring more offspring – even with females who were mated with other males. "The surprising result was that testosterone-treated males had a higher overall fitness than control males," write the authors in a study in the May issue of American Naturalist. This led to the question of why don't juncos naturally have higher levels of testosterone? Testosterone-treated males produced more offspring, but they were smaller, and smaller offspring had lower postfledging survival. Older, more experienced females preferred to mate with older males and realized higher reproductive success when they did so. While young males treated with testosterone increased their ability to attract older females, it resulted in poor reproductive performance.

Keyword: Sexual Behavior
Link ID: 8776 - Posted: 06.24.2010

With swelling prison populations, researchers are trying to understand the biology behind aggressive behavior. National Institute of Mental Health scientist Andreas Meyer-Lindenberg is looking for clues to how genes wire our brains early in life. He's focusing on a specific gene that was previously linked to impulsive violence in certain populations of people. A study in 2002 found that subjects with a particular form of a gene had a significantly higher risk of violence only if they were abused as children. While this gene-environment interaction is important in understanding this behavior, Meyer-Lindenberg wanted to focus on the genetic facets of violence. The study also found that a variation in this gene, called MAOAG, disproportionately affects men, because this gene is located on the X chromosome, which determines sex. Since men only have one X chromosome, they are more prone to the effects of the gene. Women have two X chromosomes, but the chances of having the gene variation on both chromosomes is very rare. "One of the most fascinating things," Meyer-Lindenberg says, about this field of science called psychiatric genetics, "is how it is possible that genes [can] encode for molecules that affect something as complex as behavior, even psychiatric illness such as depression and social behavior." © ScienCentral, 2000-2006.

Keyword: Aggression; Genes & Behavior
Link ID: 8775 - Posted: 06.24.2010

When 8 year-old Andrew Kilbarger of Lancaster, Ohio received three injections in his right arm, he became one of six boys participating in the first U.S. gene therapy trial for muscular dystrophy. Andrew has Duchenne Muscular Dystrophy (DMD). DMD patients lack the gene that controls production of a protein called dystrophin, which helps keep muscle cells intact. Patients with DMD usually die by the age of 25, often because of the failure of the heart and breathing muscles. The start of any new gene therapy trial is an exciting time. But for the Muscular Dystrophy Association (which funded the trial), and the participants and doctors involved at Columbus Children's Hospital, this is a particularly exciting event because for this disease, it has been a long, hard road. Researchers discovered the gene for dystrophin 20 years ago but since it is one of the largest genes known, it was too big to work with. In 2000, geneticist Xiao Xiao found a way to miniaturize the gene. His team at the University of Pittsburgh tested the "mini-dystrophin" gene in a strain of mice with muscular dystrophy. The improvement seen in the muscle tissue of the mice was dramatic, and led to the human trial that just began. "The limitation of that is the gene vehicle will not be widespread. It will… be localized around the injection site. However, diseases like muscular dystrophy affect almost every skeletal muscle cell," he says." So you cannot, in theory, inject the genes into every muscle cell directly. So we have to figure out a novel or innovative way to deliver or disseminate [the gene]." © ScienCentral, 2000-2006.

Keyword: Muscles
Link ID: 8774 - Posted: 06.24.2010

Everyone is familiar with the sinking feeling you get after deleting a computer file by mistake or leaving the house without your keys. But such events also cause their own unique reactions in the brain. US scientists writing in the Journal of Neuroscience found one area becomes more active after "costly" mistakes. They say it may help explain obsessive compulsive disorder, where minor events appear to be enough to triger an over-reaction in the same area. In the study, the brains of 12 healthy adults were examined using a functional MRI (fMRI) scanner while they were undertook 360 computer tests, such as spotting the odd one out or picking pairs of letters. Succeeding at some carried a small financial reward, while failing at others incurred penalties. Others carried no reward or penalty. People were told they had a $10 (£5.70) "credit" to begin, and that they would receive real cash depending on their balance at the end. The response to a mistake that cost them money was seen to be greater than the response to other mistakes and involved a part of the brain called the rostral anterior cingulate cortex (rACC). That part of the brain did not show the same level of activity when the mistake did not carry a penalty, or had a neutral consequence. The researchers had already found in previous research that the rACC area did become more active when there was no cost in people with OCD. (C)BBC

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 8773 - Posted: 04.14.2006

Roxanne Khamsi The first common genetic variant that substantially increases a person’s risk of obesity has been identified, researchers claim. They hope that their discovery will open doors to new treatments for the condition. The team identified a small genetic change in a region of DNA near a gene known as INSIG2 as being linked to obesity. DNA code is made up of four bases, or "letters". A single change in this particular region, from a G to a C, makes a person more prone to obesity, according to the study. They believe this change somehow affects the regulation of the gene INSIG2, which has a role in fat production. The US researchers, led by Albert Herbert at the Boston University Medical School, found that an individual with two copies of the C variant is 22% more likely to have a body mass index (BMI) greater than 30 – the point where people move from being "overweight" to "obese". This is the first study to strongly identify a genetic component in obesity in a number of populations, comments Carol Shoulders at Imperial College London, UK. © Copyright Reed Business Information Ltd

Keyword: Obesity; Genes & Behavior
Link ID: 8772 - Posted: 06.24.2010

By Shankar Vedantam Pharmaceutical giant Eli Lilly and Co. recently funded five studies that compared its antipsychotic drug Zyprexa with Risperdal, a competing drug made by Janssen. All five showed Zyprexa was superior in treating schizophrenia. But when Janssen sponsored its own studies comparing the two drugs, Risperdal came out ahead in three out of four. In fact, when psychiatrist John Davis analyzed every publicly available trial funded by the pharmaceutical industry pitting five new antipsychotic drugs against one another, nine in 10 showed that the best drug was the one made by the company funding the study. "On the basis of these contrasting findings in head-to-head trials, it appears that whichever company sponsors the trial produces the better antipsychotic drug," Davis and others wrote in the American Journal of Psychiatry. Such studies make up the bulk of the evidence that American doctors rely on to prescribe $10 billion worth of antipsychotic medications each year. Davis pointed out the potential biases in design and interpretation that produced such contradictory results. Other experts note that industry studies invariably seek to boost the image of expensive drugs that are still under patent. Moreover, they say, the trials are relatively brief and test drugs on patients with simpler problems than doctors typically encounter in daily practice. © 2006 The Washington Post Company

Keyword: Schizophrenia
Link ID: 8771 - Posted: 06.24.2010