UC Irvine researchers have uncovered significant differences in the brain activity of men and women when engaged in a broad range of activities and behavior – differences that are even more acute during impulsive or hostile acts. But when men and women have nicotine in their bodies, these brain activity differences practically disappear. Among both smokers and non-smokers on nicotine, during aggressive moments such as impulsive or hostile acts, there are virtually no differences in brain activity between the sexes – illustrating how nicotine can impact brain function. Results of the study, conducted by Brain Imaging Center researchers supported by the UCI Transdisciplinary Tobacco Use Research Center, are published in the online edition of the International Journal of Neuropsychopharmacology, and will be available in print next month. The researchers found during behavioral and brain-imaging tests on hostility and impulsive reaction that brain-metabolism activity – which indicates when neurons are working – was much higher in many brain areas of women than men. But when the test subjects were given nicotine, metabolic activity significantly declined in the women and slightly increased in men – the original differences all but disappeared. © Copyright 2002-2005 UC Regents

Keyword: Sexual Behavior; Drug Abuse
Link ID: 6889 - Posted: 06.24.2010

By DENISE GRADY Women in labor may suffer needlessly because doctors mistakenly advise them to delay a common pain treatment for fear that it will impede contractions and lead to a Caesarean section, researchers are reporting. A new study of the treatment - a type of anesthesia that injects painkiller into the spinal fluid and the epidural area around the spinal cord to numb the pelvic region - finds that giving it early or late in labor makes no difference in Caesarean rates among women having first babies. There is no reason for women to deny themselves the medicine or for doctors to withhold it, the study says. Other researchers urged caution, noting that not all hospitals offer such combined anesthesia and that the findings might not apply to all epidural treatments. About 60 percent of American women have epidural anesthesia during childbirth. Dr. Cynthia A. Wong, the lead author of the new study and an obstetric anesthesiologist at Northwestern Memorial Hospital in Chicago, said women were often pressured to delay the treatment and made to feel guilty or weak if they asked for one too soon. Copyright 2005 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 6888 - Posted: 02.17.2005

DALLAS – – New findings by researchers at UT Southwestern Medical Center challenge one of the established views of how nerve cells communicate with one another. Every time we move, feel emotions, think or remember, the nerve cells, or neurons, in our body transmit messages to one another via chemical signals called neurotransmitters. Within neurons are tiny organelles called synaptic vesicles that sequester neurotransmitters and release them when needed into the synapse, or space between nerve cells, where the chemical signal is transmitted to other neurons. It is known that synaptic vesicles release their neurotransmitters in two different "modes" – one when the neuron is stimulated and actively relaying a message, and the other through spontaneous release when the neuron is "at rest," or inactive. Until now it was believed that the same synaptic vesicles were responsible for releasing neurotransmitters in both modes. However, new research by UT Southwestern scientists appearing in the Feb. 17 issue of the journal Neuron suggests that two distinct types of synaptic vesicles are responsible for the two different modes of neurotransmitter release – one type of vesicle for spontaneous release, another vesicle associated with activity-dependent release.

Keyword: Miscellaneous
Link ID: 6887 - Posted: 06.24.2010

With obesity having reached epidemic levels around the world, nutrition experts are always telling us to eat better. So, what if each bite of a hamburger conjured up unpleasant memories? Psychologist Elizabeth Loftus from the University of California, Irvine suggests that changing people's memories might alter their behavior. "If we made people believe that they got sick eating a particular food, maybe we would be able to show that down the road they didn't want to eat that food as much," Loftus explains. She was able to convince about a third of a group of volunteers that had had a bad experience as a child after eating certain foods. "We were able to make people believe that they had gotten sick eating this particular food." Studying memory and memory manipulation for quite some time, Loftus and her research team, as well as collaborators at The University of Washington, have worked to reveal how things that we are told can change our memories. "We've done quite a few studies where we either distort memory for a detail here or there, or we plant an entirely false memory," Loftus says. Food-related memories seemed like an obvious choice as an easy way to see a consequence that they could look for. "We were looking for a false belief or a false memory that we could plant that would allow us to measure the subsequent repercussions of adopting this false memory." © ScienCentral, 2000- 2005.

Keyword: Learning & Memory
Link ID: 6886 - Posted: 06.24.2010

Researchers have long puzzled over the apparently multiple causes of complex developmental disorders such as schizophrenia. Individuals seem to be predisposed to the disease by a tragic, mysterious combination of genetics, prenatal trauma, viral infection, and early experience. And its array of symptoms--including hallucinations, delusions, paranoia, and antisocial behavior--has defied simple explanation. In experiments with rats, however, researchers led by led by Gerard J.M. Martens of the Nijmegen Center for Molecular Life Sciences (NCMLS) have demonstrated that such seemingly diverse combinations of symptoms can arise from a subtle imbalance in the activity of a single gene whose protein plays a key role in neural development. The researchers studied the genetic differences between rats bred to be either resistant or susceptible to the drug apomorphine. A long history of studies has revealed that apomorphine-susceptible rats show many behavioral and biochemical differences from normal rats. What's more, the tendency to develop these differences depends on their exposure to stress in early life.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 6885 - Posted: 02.17.2005

By Karen Wright Let’s start with a straightforward fact: Mercury is unimaginably toxic and dangerous. A single drop on a human hand can be irreversibly fatal. A single drop in a large lake can make all the fish in it unsafe to eat. Often referred to as quicksilver, mercury is the only common metal that is liquid at room temperature. Alchemists, including the young Sir Isaac Newton, believed it was the source of gold. In the modern era, it became a common ingredient of paints, diuretics, pesticides, batteries, fluorescent lightbulbs, skin creams, antifungal agents, vaccines for children, and of course, thermometers. There is probably some in your mouth right now: So-called silver dental fillings are half mercury. Mercury is also a by-product of many industrial processes. In the United States coal-fired power plants alone pump about 50 tons of it into the air each year. That mercury rains out of the sky into oceans, lakes, rivers, and streams, where it becomes concentrated in the flesh of fish, shellfish, seals, and whales. Last year the Food and Drug Administration determined there is so much mercury in the sea that women of childbearing age should severely limit their consumption of larger ocean fish. The warning comes too late for many mothers. A nationwide survey by the Centers for Disease Control shows that one in 12 women of childbearing age already have unsafe blood levels of mercury and that as many as 600,000 babies in the United States could be at risk. But that begs a critical question: At risk for what? © 2004 The Walt Disney Company

Keyword: Neurotoxins
Link ID: 6884 - Posted: 06.24.2010

While the brain center called the nucleus accumbens (NAc) has been called a key component of the brain's "reward" pathways, researchers' experiments with rats have now shown that the center processes not only rewarding stimuli, but also aversive stimuli. The researchers found that not only does the NAc decide whether stimuli--in this case sweet sucrose or bitter quinine--are rewarding or aversive, but the center's neurons also encode learning associated with the stimuli. The NAc is located in the brain's limbic system, which generates feelings and emotions. It is the key brain center involved in reinforcing the taking of drugs of abuse. In their experiments, researchers led by Mitchell F. Roitman and Regina M. Carelli at Dr. Carelli's laboratory at University of North Carolina in Chapel Hill used recording microelectrodes to measure the electrophysiological response of neurons in the NAc of rats when they fed the rats small squirts of sucrose or quinine. The rats actively responded to the two tastes. For sucrose, they immediately licked and moved their mouths to ingest the sugar. In response to quinine, they gaped their mouths and rubbed their chins--the rat equivalent of "ptui."

Keyword: Chemical Senses (Smell & Taste); Drug Abuse
Link ID: 6883 - Posted: 02.17.2005

Rossella Lorenzi, Discovery News — Sleep helps young birds master the art of song, according to a study that analyzed and recorded every vocalization made by young male zebra finches through cycles of wakefulness and sleep. The study, which appears in the current issue of Nature, showed that just woken up zebra finches are dramatically worse singers than they were the day before. But surprisingly, after intense morning singing, the worst performers become the best singers of all. Zebra finch males are active in the daytime, do not sing in darkness and develop their song during a critical window of "brain plasticity" between 30 and 90 days after hatching. In order to investigate how sleep affects developmental learning in these colorful songbirds, behavioral neuroscientists Ofer Tchernichovski and Sébastien Deregnaucourt from City College New York, recorded the entire song development of zebra finches. Copyright © 2005 Discovery Communications Inc.

Keyword: Learning & Memory; Sleep
Link ID: 6882 - Posted: 06.24.2010

Emma Marris Birds that live in bunches work each other up into a reproductive frenzy with their songs, according to research that confirms an old hypothesis. As far back as the 1930s, ornithologists proposed that large, sociable colonies of birds would tend to have earlier, bigger and more closely synchronized clutches of eggs. Known as the Darling hypothesis, after F. Fraser Darling who first suggested the idea, it has finally been supported by experiments in the laboratory, and the research appears online in the Proceedings of the Royal Society1. To test Darling's hypothesis, the researchers set up two indoor colonies of the zebra finch (Taeniopygia guttata), a smart little Australian bird often seen in pet shops. The first group of birds was played recorded sounds of its own colony, but the second group heard a playback that blended its own colony sounds with noises from extra finches.Females in the second group had more eggs, laying them earlier and more synchronously than controls, confirming the theory. ©2005 Nature Publishing Group

Keyword: Sexual Behavior; Language
Link ID: 6881 - Posted: 06.24.2010

Pregnant women are attracted to healthier looking faces in what scientists believe is a subconscious effort to avoid illness. Teams from the universities of St Andrews and Aberdeen showed pregnant women two pictures of computer- generated faces. The faces were tweaked to show one unhealthy pallor and the other healthy. Women with high levels of the progesterone hormone chose the healthier face. Dr Ben Jones, of the University of Aberdeen, said pregnant women and those with raised progesterone are more attracted to men who appear healthier. He said: "Our findings suggest that pregnancy, or when a woman is in a similar hormonal state, trigger strategies within the body for avoiding illness during social interactions. "These could compensate for weakened immune system responses at these times and reduce the risk of maternal illness disrupting the development of the unborn child." The tests were carried out at the Perception Lab at St Andrews University. (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 6880 - Posted: 02.16.2005

Birdsong delights listeners and intrigues evolutionary ecologists. Female birds are thought to preferentially mate with males with more complex or extravagant songs. But why should females prefer these males? What information does a male's song convey? Jane M. Reid and fellow researchers studied a population of song sparrows inhabiting Mandarte Island, British Columbia, Canada, where males sing elaborate repertoires of songs. They found that male sparrows with larger song repertoire sizes contributed more offspring and grand-offspring to the breeding population on Mandarte. This was because these males lived longer and reared more hatched chicks to independence from parental care, not because the females who mated to males with larger repertoires laid or hatched more eggs. Furthermore, they discovered that independent offspring of males with larger repertoires were more likely to survive to breed and then to leave more grand-offspring than independent offspring of males with small repertoires. This effect of paternal repertoire size on offspring performance was stronger in sons than in daughters.

Keyword: Sexual Behavior; Evolution
Link ID: 6879 - Posted: 02.16.2005

Oliver Wendell Holmes coined the term "anesthesia" in 1846 to describe drug-induced insensibility to sensation (particularly pain), shortly after the first publicized demonstration of inhaled ether rendered a patient unresponsive during a surgical procedure. Two broad classes of pharmacologic agents, local and general, can result in anesthesia. Local anesthetics, such as Novocain, block nerve transmission to pain centers in the central nervous system by binding to and inhibiting the function of an ion channel in the cell membrane of nerve cells known as the sodium channel. This action obstructs the movement of nerve impulses near the site of injection, but there are no changes in awareness and sense perception in other areas. In contrast, general anesthetics induce a different sort of anesthetic state, one of general insensibility to pain. The patient loses awareness yet his vital physiologic functions, such as breathing and maintenance of blood pressure, continue to function. Less is known about the mechanism of action of general anesthetics compared to locals, despite their use for more than 150 years. The most commonly used general anesthetic agents are administered by breathing and are thus termed inhalational or volatile anesthetics. They are structurally related to ether, the original anesthetic. Their primary site of action is in the central nervous system, where they inhibit nerve transmission by a mechanism distinct from that of local anesthetics. The general anesthetics cause a reduction in nerve transmission at synapses, the sites at which neurotransmitters are released and exert their initial action in the body. But precisely how inhalational anesthetics inhibit synaptic neurotransmission is not yet fully understood. It is clear, however, that volatile anesthetics, which are more soluble in lipids than in water, primarily affect the function of ion channel and neurotransmitter receptor proteins in the membranes of nerve cells, which are lipid environments. © 1996-2005 Scientific American, Inc

Keyword: Pain & Touch
Link ID: 6878 - Posted: 06.24.2010

Here's what Mary Jo O'Kelley avoids thanks to a warehouse accident that left her with chronic back pain: bending, squatting, exercising and lifting anything of almost any kind. But that might not be all the damage her injury caused. For the first time, researchers have found evidence that chronic back pain may be at least partially responsible for shrinking the brain. Neuroscientist Vania Apkarian of Northwestern University used magnetic resonance imaging (MRI) scans to collect 26 brain images from people who reported suffering back pain that lasted for a year or more and 26 images from pain-free subjects matched for age and sex. After looking at average brain size across each group, he compared the pain subjects with subjects free of pain and found significant differences in brain density in gray matter—the tissue in the brain that houses neurons, or nerve cells, that communicate with each other to help us process information. With age, we naturally lose some gray matter but Apkarian notes a difference when pain comes into play. "The amount of gray matter decrease per year that we see for normal aging is about 2.5 ccs in volume; that's about a teaspoon," he explains. "The chronic back pain condition has an additional half a teaspoon, about 1.5 cc of additional of gray matter brain atrophy on top of the normal aging effect." Loss of gray matter that results from chronic pain—he's found it's generally in the pre-frontal cortex and the thalamus—can bring cognition problems, as Apkarian explains: "Neurons are probably not functioning as well as they should be functioning, all of which will decrease that ability of that area of the brain to process the kinds of things that are involved in processing in everyday behavior." © ScienCentral, 2000- 2005.

Keyword: Pain & Touch
Link ID: 6877 - Posted: 06.24.2010

Robots that act like rat pups can tell us something about the behavior of both, according to UC Davis researchers. Sanjay Joshi, assistant professor of mechanical and aeronautical engineering, and associate professor of psychology Jeffrey Schank have recorded the behavior of rat pups and built rat-like robots with the same basic senses and motor skills to see how behavior can emerge from a simple set of rules. Seven to 10-day-old rat pups, blind and deaf, do not seem to do a whole lot. Videotaped in a rectangular arena in Schank's laboratory, they move about until they hit a wall, feel their way along the wall until their nose goes into a corner, then mostly stay put. Because their senses and responses are so limited, pups should be a good starting point for building robots that can do the same thing. Joshi's laboratory built foot-long robots with tapered snouts, about the same shape as a rat pup. The robots are ringed by sensors so that they "feel" when they bump into a wall or corner. They are programmed to stay in contact with objects they touch, as rats do. But when the robotic "rats" were put into a rectangular arena like that used for experiments with real rats, the robots showed a new behavior. They scuttled along the walls and repeatedly bumped into one corner, but favored one wall. Instead of stopping in a corner they kept going, circling the arena.

Keyword: Robotics
Link ID: 6876 - Posted: 02.16.2005

By Sandra G. Boodman From the time her son was born, Jennifer DeWeese said, she suspected something was wrong. As an infant he cried inconsolably and slept mostly in hour-long snatches. At 3, he was always irritable and had prolonged tantrums triggered by the slightest change in his routine. A therapist told his mother he was emotionally disturbed and suggested she read a popular book about childhood bipolar disorder. A year later a child psychiatrist in Virginia Beach made the diagnosis: the 4 1/2 -year-old was manic-depressive. A few months later, when his even-tempered sister grew moody and volatile, DeWeese took her to the same psychiatrist. They sat down with DeWeese's well-thumbed book about bipolar children and went through its symptom checklist. Based largely on those results and the family's history -- DeWeese said she learned during her divorce that the children's father had been diagnosed as bipolar in high school -- the psychiatrist told DeWeese her 5 1/2-year-old daughter was bipolar, too. "I feel relieved to know there is something causing their symptoms and something we can do about it," said DeWeese, 34. She is convinced, she said, that her children's problems are inherited, not a reaction to their father's permanent departure, a bitter divorce marked by allegations of spousal abuse, a bankruptcy that resulted in the loss of the family's house and car, DeWeese's frequent hospitalizations for kidney disease and the arrival of a new stepfather. Now 6 and 8, DeWeese's son and daughter exemplify a trend that is roiling mental heath: the burgeoning number of children diagnosed with bipolar illness, also known as manic depression, which affects about 2.3 million Americans. © Copyright 1996-2005 The Washington Post Company

Keyword: Schizophrenia; Depression
Link ID: 6875 - Posted: 06.24.2010

By JANE E. BRODY My surgeon did a marvelous job replacing my arthritic knees and, at the same time, straightening my terribly bowed legs when, at 63, I decided to have knee replacement surgery. Although a class given at the hospital before the operation repeatedly emphasized the importance of adequate pain control, the surgeon and his helpers were not experts in treating prolonged, debilitating postoperative pain. They are hardly alone. Pain management is not generally taught as a part of medical education, not even to residents in orthopedic surgery. As a result, most doctors are clueless or unnecessarily cautious about treating pain, especially chronic pain like that caused by incurable neurological or muscular disorders. They are especially ill-informed about opioids, which are synthetic versions of morphine, the most potent painkillers that can be taken by mouth. As Dr. Jennifer P. Schneider writes about opioids in her book "Living With Chronic Pain" (Healthy Living Books, $15.95), "Fear and lack of knowledge of these drugs prevent many doctors from prescribing them for people whose pain is caused by anything other than cancer." Copyright 2005 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 6874 - Posted: 02.15.2005

By ANDREW POLLACK Despite all the advances of modern medicine, the main drugs used to fight pain today are essentially the same as those used in ancient times. Hippocrates wrote about the pain-soothing effects of willow bark and leaves as early as 400 B.C. Opium was cultivated long before that. Aspirin and morphine, based on the active ingredients in these traditional remedies, were isolated in the 1800's and helped form the foundation of the modern pharmaceutical industry. But scientists are now trying to find new ways of fighting pain. The effort has been given new impetus by the recent withdrawal of Vioxx and the questions surrounding the safety of similar pills like Celebrex and Bextra. Those concerns come on top of the problems of abuse of narcotic painkillers like OxyContin. "There's a huge void, and no one is filling it," said Remi Barbier, chief executive of Pain Therapeutics, a company in South San Francisco, Calif. But Dr. Barbier's company and dozens of others are trying. And some new treatments may come from things in nature that soothe or sting, like marijuana, hot chili peppers, nicotine and deadly toxins of snails and fish. While the withdrawal of Vioxx leaves more room for newcomers, it also makes their challenge harder. Not only have opioids and aspirin been hard to beat, but the Food and Drug Administration is now expected to demand more evidence that drugs are safe before approving them. Copyright 2005 The New York Times Company

Keyword: Pain & Touch
Link ID: 6873 - Posted: 02.15.2005

The following statement is being released by the Parkinson’s Disease Foundation, located at 710 West 168th Street, New York City. It follows the announcement, earlier today, of a decision by Amgen Incorporated, manufacturer of GDNF, an experimental neural growth factor, to forgo the offer of reinstatement of GDNF to patients who were involved in recent clinical trials of the treatment. The authors of the PDF statement are Stanley Fahn, M.D., the Foundation’s Scientific Director, and Robin Anthony Elliott, its Executive Director. "The Amgen announcement, which followed a resolution by the PDF Board of Directors urging the company to permit patients who participated in the company’s clinical trials the option of continued access to GDNF, is deeply disappointing to PDF, to the Parkinson’s community, and to the participating patients," the statement reads. "However well-intentioned the company may have been in wrestling with this issue, we believe it has reached the wrong decision – whether judged in terms of science, or the desires of the people who participated in the clinical trials, or the issues of safety." "In terms of the science, we would argue that the reinstatement of GDNF, if accompanied by the continuing collection of efficacy and safety data, would enable scientists and regulatory authorities to monitor the long-term aspects of safety and efficacy of the treatment. Furthermore, the observation of increased fluorodopa uptake in PET scans needs to be carefully followed over time to determine if this will eventually translate into clinical improvement. Giving up this opportunity to learn is, in our view, a mistake." © 2005 The Parkinson’s Disease Foundation

Keyword: Parkinsons; Trophic Factors
Link ID: 6872 - Posted: 06.24.2010

The supersensitivity to dopamine that is characteristic of schizophrenia can be caused by mutations to a wide variety of genes, rather than alterations to just two or three specific genes, says a University of Toronto researcher. In research published in the Feb. 15 edition of the Proceedings of the National Academy of Sciences, University of Toronto pharmacology professor Philip Seeman and his 16 colleagues in eight universities show that mutations to genes that have no relation to the brain's dopamine receptors can still cause those receptors to become highly sensitive to their own dopamine, a condition that leads to psychosis. By examining brain tissue from mice with various gene mutations, the researchers determined that the brain appears to compensate for the altered gene by becoming supersensitive to dopamine. Dopamine is a neurotransmitter that allows people to move, think and feel. "The altered genes may provoke the brain to respond and compensate, and compensation often involves the dopamine system going into high gear," says Seeman. "The brain knows about mistakes, and to protect itself, it makes sense for the compensation to re-adjust the dopamine system to preserve the functions – such as movement and thought – that the body and brain needs."

Keyword: Schizophrenia; Genes & Behavior
Link ID: 6871 - Posted: 06.24.2010

Your parents may have told you about the birds and bees, but scientists are learning a bit about love from fruit flies. As this ScienCentral News video explains, biologists studying flirtatious flies are learning how our genes shape sex appeal—and everything else. For a certain species of male fruit fly, the wing's the thing—male sex appeal boils down to a black spot on the suitor's wings. "The species that have these spots have an elaborate courtship ritual where they dart out in front of the females and they extend their wings and do a little dance while they display these spots," says Sean Carroll, genetics professor at the University of Wisconsin-Madison and Howard Hughes Medical Institute. "It's quite clear that these spots are a visual cue that the females are picking up on in the selection of mates, and the success of mating of males being linked to their possession of this trait—that process is called sexual selection and it's a very powerful evolutionary force." Since fruit flies have long been the workhorses of genetics, Carroll and his colleagues used them to study how such traits evolve at the genetic level. Biologists already knew that every gene has two parts—the DNA that does the work, and the DNA that tells the gene where to work. "And one of the biggest questions in evolution," says Carroll, "is what parts are evolving, is it the part that does the work, or is it the instructions for where that work's going to be done?" © ScienCentral, 2000- 2005.

Keyword: Sexual Behavior; Evolution
Link ID: 6870 - Posted: 06.24.2010