Real-time monitoring of dopamine activity in the brain shows that in rats the mere anticipation of receiving cocaine may cause significant increases in dopamine levels. This finding may help explain why, in humans recovering from cocaine addiction, cocaine paraphernalia, surroundings, and other factors associated with drug use can elicit an intense craving for the drug, often resulting in relapse to use. Dopamine is a brain chemical associated with feelings of pleasure (reward); increases in dopamine levels in an area of the brain called the nucleus accumbens have been associated with drug use. Measuring dopamine level changes in real time enable researchers to carefully and accurately correlate drug-related behaviors in rats with changes in brain chemistry. The researchers trained male rats to self-administer cocaine by pressing a lever and to associate the availability of cocaine with certain cues such as changes in lighting and an auditory tone. During daily sessions, the rats had access to cocaine and their behavior was recorded. Using fast-scan cyclic voltammetry, the researchers monitored changes in dopamine levels in the nucleus accumbens of the rats every 100 milliseconds while the rats had access to cocaine or were exposed to drug-related cues. Voltammetry allows subsecond measurements of dopamine release by monitoring changes in electrochemical currents that occur when brain cells release dopamine.

Keyword: Drug Abuse
Link ID: 3768 - Posted: 05.04.2003

Lobeline, a drug with a long history of use in smoking cessation programs, may be a potential treatment for methamphetamine abuse. In a previous study using rats, researchers from the University of Kentucky found that lobeline decreased the animals' self-administration of d-methamphetamine (METH). They concluded that lobeline acted by decreasing the animal's perception of METH- induced pleasure (reward). The researchers conducted a series of experiments with male rats that were trained to self-administer METH by pressing a lever. In a group of rats that consistently self-administered METH, the researchers exchanged METH with lobeline to determine whether lobeline would serve as a substitute for METH. When METH was exchanged with lobeline, the number of times the rats pressed the lever decreased daily over the course of the experiment, indicating that lobeline did not serve as substitute for METH. In a different experiment, the researchers investigated whether lobeline would cause rats to resume drug-seeking behavior after a period of abstinence or if it alters METH-induced reinstatement of drug-seeking behavior. They found that lobeline did not restore drug-seeking behavior nor did it alter METH-induced reinstatement. These findings indicate that lobeline appears to alter the mechanisms mediating METH reward, but not the mechanisms mediating the reinstatement of drug-seeking behavior.

Keyword: Drug Abuse
Link ID: 3767 - Posted: 05.04.2003

(Embargoed) CHAPEL HILL-- A significant percentage of children with attention-deficit-hyperactivity disorder did just as well when harmless placebos, pills without any specific effect, replaced some of their medications, a study led by two N.C researchers shows. The findings raise the possibility that some children with these common problems may be effectively treated on lower doses of medication that are supplemented with a placebo. Further research is necessary, the researchers said, to determine the mechanism of the effect that placebos had in treating the disorder. Dr. Adrian Sandler, a developmental-behavioral pediatrician at the Mission Children's Hospital in Asheville, and Dr. James W. Bodfish, a professor in the University of North Carolina at Chapel Hill department of psychiatry, presented their study findings today (May 3) at the annual meeting of the Pediatric Academic Societies in Seattle.

Keyword: ADHD
Link ID: 3766 - Posted: 05.04.2003

By Jason Socrates Bardi "Jack" and "Dianne" are hard working midwesterners, sweethearts since high school, loving parents, and both carriers of a recessive gene defect that they are not aware of. Jack and Diane have four children and their youngest, call him "Jake," has the misfortune to have inherited copies of the bad gene from both parents. Despite the fact that his parents and older siblings are all generally healthy, Jake is born without the ability to hear. Hearing aids prove to be of no help, so Jake, his parents, and siblings all learn sign language. Jake has other problems, too. He has trouble balancing and is a late walker—not taking his first steps until he is almost two years old. Throughout his childhood, he has to hold on to something solid when he sits down. Around age 10, the real trouble starts. Jake starts to have difficulty seeing at night, and by the time Jake is in his late teens, he is completely blind and no longer able to communicate. Copyright © 1992-2003 Bio Online, Inc.

Keyword: Hearing; Genes & Behavior
Link ID: 3765 - Posted: 06.24.2010

First evidence of animal creating markers to navigate. HANNAH HOAG Wood mice fashion portable signposts from bright leaves and shells when they explore fields for food, a new study suggests1. This is the first time that animals other than humans have been found to use moveable landmarks. "No one thought that mice would be clever enough to use tools for navigation," says biologist Pavel Stopka of Charles University in Prague, the Czech Republic. Wood mice live in large fields that often lack features that they might use to locate nests, food sources or danger zones. So the animals build bundles of leaves and twigs as they explore, report Stopka and his colleague, David Macdonald of the University of Oxford, UK. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Animal Migration
Link ID: 3764 - Posted: 06.24.2010

Seal pups can recognize their mother's distinct vocal call within two days of birth says a University of Alberta researcher--a finding essential to the pups' care and survival. Dr. Isabelle Charrier, from the U of A's Faculty of Science, has extensively studied how mothers and seal pups use vocal recognition to identify each other. Her findings are published in the current issue of the international journal, Animal Behaviour. Charrier spent nine months on Amsterdam Island in the Indian Ocean, studying and recording acoustic recognition between the female and her pups. When these fur seals come ashore to breed in dense colonies, the lactating females must leave their newborn pups on land while they forage for food at sea. As with most social species, the fur pups only feed their own offspring so when the mother returns from sea, it is essential for the mother and pup to find each other among the several hundred other mammals. "We found out that pups can recognize their mother's call within two to five days after birth," said Charrier. "This is surprisingly quick but considering that the mother leaves seven days after giving birth it is important to have that immediate recognition."

Keyword: Animal Communication; Sexual Behavior
Link ID: 3763 - Posted: 05.02.2003

The death of sensory hair cells when they try to multiply suggests need for caution in attempts to restore many kinds of lost cells through gene therapy (LOS ANGELES--) Researchers may have found a link between progressive hearing loss and a gene called p19Ink4d (Ink4d), according to results of a study that measured loss of hearing in mice lacking that gene. Normally, the Ink4d gene keeps healthy cells "quiet" – from inappropriately dividing. Mice lacking the Ink4d gene become progressively hearing impaired because the absence of Ink4d causes certain cells in their inner ears to attempt to divide. However, this inappropriate attempt to divide causes these cells, called sensory hair cells, to instead commit suicide, according to a team of researchers that includes two St. Jude investigators and scientists from the House Ear Institute in Los Angeles, CA. This finding in mice represents a potentially unrecognized form of progressive hearing loss, a problem that also occurs in humans, according to the investigators. If problems in Ink4d also occur in humans, this finding could explain the slow development of deafness in some people. In the absence of the braking effect of normally functioning Ink4d genes, sensory hair cells in people's ears might attempt to divide, setting off a biological response called apoptosis, or programmed cell death.

Keyword: Hearing; Genes & Behavior
Link ID: 3762 - Posted: 06.24.2010

Scientists may have discovered why the brain’s higher information-processing center slows down in old age, affecting everything from language, to vision, to motor skills. The findings may also point toward drugs for reversing the process. A brain chemical called GABA helps neurons stay finicky about which signals they respond to – a must for the brain to function at its peak. Certain neurons in very old macaque monkeys lose their pickiness, researchers have found, seemingly because they don’t get enough GABA. These results appear in the journal Science, published by the American Association for the Advancement of Science (AAAS). If a lack of GABA is indeed responsible for the old neurons’ indiscriminate firing, this problem may be simple enough to treat. Existing drugs, such as Xanax, increase GABA production, according to author Audie Leventhal of the University of Utah School of Medicine. These drugs haven’t been carefully tested on the elderly, though.

Keyword: Alzheimers
Link ID: 3761 - Posted: 06.24.2010

Cannabis smoking could be responsible for up to 30,000 deaths in the UK, estimate doctors from Imperial College London and St Mary's Hospital. Their editorial published in today's British Medical Journal, argues that cannabis could be a major contributor to deaths in the UK. The researchers calculate that if 120,000 deaths are caused among 13 million smokers, the corresponding figure among 3.2 million cannabis smokers would be 30,000, assuming that their health effects are the same. Professor John Henry from Imperial College London, and one of the authors, comments: "Even if the number of deaths attributable to cannabis smoking turned out to be a fraction of the 30,000 we believe could be possible, cannabis smoking would still be described as a major health hazard. If we also add in the likely mental health burden to that of medical illnesses and premature death, the potential effects of cannabis cannot be ignored."

Keyword: Drug Abuse
Link ID: 3760 - Posted: 05.02.2003

Birds can be influenced in the same way as human consumers as they work out what to eat, says a study. Research by British and Canadian scientists found that their preferences could be manipulated by using techniques to those employed in supermarkets. In shops, the correct positioning of items to maximise sales is regarded as a science. One tactic used by large stores is to place an eye-catching "decoy" product right next to stocks of the product they actually want to sell. The attractiveness of the target brand is enhanced by this, and sales go up. However, the team of researchers, including some from Newcastle University, UK, found that birds appear to be equally vulnerable to such trickery. They studied the behaviour of 12 rufous hummingbirds, which live in the Canadian Rocky Mountains. (C) BBC

Keyword: Obesity
Link ID: 3759 - Posted: 05.01.2003

Exclusive from New Scientist Print Edition They were certainly geniuses, but did Albert Einstein and Isaac Newton also have autism? According to autism expert Simon Baron-Cohen, they might both have shown many signs of Asperger syndrome, a form of the condition that does not cause learning difficulties. Although he admits that it is impossible to make a definite diagnosis for someone who is no longer living, Baron-Cohen says he hopes this kind of analysis can shed light on why some people with autism excel in life, while others struggle. Autism is heritable, and there are clues that the genes for autism are linked to those that confer a talent for grasping complex systems - anything from computer programs to musical techniques. Mathematicians, engineers and physicists, for instance, tend to have a relatively high rate of autism among their relatives. © Copyright Reed Business Information Ltd.

Keyword: Autism
Link ID: 3758 - Posted: 06.24.2010

Gene hint to human reading ability. HELEN PEARSON A Finnish family has given the first clear clue to a gene involved in dyslexia. Between 5 and 15% of people are dyslexic. They have problems reading, writing and spelling. Although scientists have suspected that genes are involved, they had not come up with a convincing candidate - until now. One gene is mutated in around 10% of Finnish dyslexics, compared with 2-3% in the rest of the population, Juha Kere of the University of Helsinki, Finland and his team found. "If you have the gene you become more susceptible, but you're not necessarily dyslexic," he says. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Dyslexia; Genes & Behavior
Link ID: 3757 - Posted: 06.24.2010

Peer into the deep recesses of an ant colony and you'll discover an extremely well organized community with thousands of workers quietly going about their jobs. Some dig nests while others gather food or tend the young. Remarkably, every chore is done without supervision or direction, and some workers even switch jobs to meet the ever-changing needs of the colony. How does an insect with a brain the size of a poppy seed decide to carry out a particular task? The answer, says a team of Stanford University biologists, has less to do with brainpower than with the ant`s extraordinary sense of smell. Writing in the journal Nature, the Stanford scientists found that, when a parade of patroller ants returns to the nest, their distinctive body odor cues other workers to go out and forage for food. This new insight into the behavior of social insects is the latest discovery to emerge from a 20-year field study of red harvester ants (Pogonomyrmex barbatus) in the southern Arizona desert - a project designed and led by Deborah M. Gordon, an associate professor of biological sciences at Stanford. "The question is, how does a worker know what to do?" said Gordon, coauthor of the May 1 Nature study. "There's nobody in charge, there's nobody telling it what to do."

Keyword: Chemical Senses (Smell & Taste); Animal Communication
Link ID: 3756 - Posted: 05.01.2003

DURHAM, N.C. -- Researchers have discovered that some iridescent butterflies use the polarization of light refracted from their intricate prismatic scales as a mating signal -- the first time that light polarization has been identified as a mating signal for any terrestrial animal species. The discovery was reported in an article in the May 1 Nature by Duke University biologists Alison Sweeney and Sönke Johnson, and Christopher Jiggins of the University of Edinburgh in Scotland. The research was sponsored by the National Science Foundation. The initial mystery that attracted her, said graduate student Sweeney, was why butterflies possessed such intricate iridescent structures on their wings.

Keyword: Sexual Behavior
Link ID: 3755 - Posted: 06.24.2010

Voltage-dependent channel structure reveals masterpiece responsible for all nerve, muscle activity Imagine evaluating sculptures without the privilege of sight. The task of analyzing visual art would shrink to partial, indirect descriptions that fail in conveying the object's true character. Some aspects of the work of art and its surroundings would still be accessible, but ultimately the analysis would be unsatisfying, inaccurate and misleading. The masterpiece is a voltage-dependent potassium ion channel, the first published picture of which illustrates the cover of Nature's May 1 edition, revealed by MacKinnon and his rainmaking group of biophysicist-crystallographers. Inside, Nature features two articles, co-authored by Vanessa Ruta, Alice Lee, Jiayun Chen, Brian Chait, D. Phil., and Martine Cadene, Ph.D. that correct the proposals of scientists who lacked the definitive picture showing a potassium channel with charge-triggered "paddles" responsible for opening and closing a passage for potassium ions to freely move through.

Keyword: Miscellaneous
Link ID: 3754 - Posted: 05.01.2003

Until now, doctors could only measure the physical spread of Alzheimer’s disease by examining the brains of deceased patients after it was too late to help them. But with a new brain scanning technique, now they can see the disease progressing in living patients, which will allow them to pinpoint where and how fast the disease is spreading, and reveal whether drugs and vaccines combat the brain damage that Alzheimer’s causes. Neuroscientists from the University of California Los Angeles (UCLA) and the University of Queensland in Australia used a new imaging analysis technique to track the spread of Alzheimer’s-related cell death in living patients. They detected changes in brain scans created using magnetic resonance imaging (MRI), and created the first 3-D, time-lapse video map showing the spread of Alzheimer’s disease. “This is the first technique to actually watch the physical spread of Alzheimer’s in the [living] brain,” says Paul Thompson, assistant professor of neurology at the David Geffen School of Medicine at UCLA, the study’s chief investigator. “You can use this to look at drug effects, whether they are helping a patient. You can use it for early diagnosis, to see if a person actually has Alzheimer’s. You can also use it to tell if a patient is aging healthily.” © ScienCentral, 2000-2003

Keyword: Alzheimers; Brain imaging
Link ID: 3753 - Posted: 06.24.2010

NewScientist.com news service Fish are capable of experiencing pain. This is the conclusion of researchers who observed rainbow trout behaviour after the animals were given injections that would be painful to people. Other scientists reject their interpretation, but the study could still be used by anti-angling campaigners. The argument over whether fishing is a "blood sport" in the same vein as fox hunting and hare coursing has hinged on whether fish feel pain in a similar way to animals. If they do not, as most researchers currently believe, then the animal welfare argument against angling largely falls apart. Lynne Sneddon at the Roslin Institute, near Edinburgh, Scotland, and her colleagues, took measurements from individual neurons in anaesthetised fish while they poked the fish's heads and applied acid and heat. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Animal Rights
Link ID: 3752 - Posted: 06.24.2010

Most dog owners have experienced that moment when the soulful eyes of their companions look to their empty dog dishes, up into their humans' eyes, and back to the empty dog dish. That propensity to look at humans' faces may be the key difference between dogs and their wolf ancestors. Most researchers agree that dogs diverged from wolves and took up residence with humans over 10,000 years ago. But how the split occurred and how much dogs differ from wolves isn't known. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 3751 - Posted: 06.24.2010

Potential targets to slow disease The main pathological signature of Alzheimer disease (AD), which causes progressive memory loss in its victims, is plaques in the brain. Currently, massive research efforts are geared toward eliminating these plaques. In a new study published in the April issue of the Journal of Neuroscience, researchers at the Alzheimer Research Laboratory at Case Western Reserve University School of Medicine report finding the molecules that play a critical role in making the brain think it is under attack from these plaques, triggering immune cells in the brain. The inflammation mediated by these cells speeds up the debilitating consequences of AD. With the discovery of these molecules, researchers say new therapies could be devised aimed at blocking their action to slow down progression of AD. From previous studies looking at people with rheumatoid arthritis, scientists know that people on non-steroidal, anti-inflammatory drugs, such as ibuprofen, have a lower incidence of AD. Gary Landreth, Ph.D., professor of neurosciences at CWRU, and his team, are searching for why this happens.

Keyword: Alzheimers
Link ID: 3750 - Posted: 04.30.2003

By LAURIE TARKAN Without so much as a nick to her scalp, Cheryl Hogarth had major brain surgery on a tumor that had grown to nearly the size of a Ping-Pong ball deep within her brain. Ms. Hogarth, who at 37 was told her malignant tumor was inoperable and given a prognosis of six months to live, went under the Gamma Knife, no-knife surgery that blasts its target with hundreds of high-intensity radiation beams in a single session. There was none of the cutting, bleeding, general anesthesia, ear-to-ear scar or long recovery associated with traditional craniotomy. She went home that evening. Two years after the surgery, Ms. Hogarth, a Sacramento mother of two, is a survivor. She takes chemotherapy to supplement the treatment, and the tumor has not grown. "I now have hope that I will be here to watch my children grow up," she said. Copyright 2003 The New York Times Company

Keyword: Miscellaneous
Link ID: 3749 - Posted: 04.29.2003