The mystery of cot death may be explained by new research published online in Nature Neuroscience today [Sunday 12 February 2006]. A failure to 'gasp' has long been proposed as the basis for sudden infant death syndrome, or cot death. A team at the University of Bristol has discovered a subset of cells in the brain that have the ability to self-generate nervous impulses, which appear essential for gasping. These cells have been termed 'pacemakers'. Professor Julian Paton who heads up the research team at Bristol University said: "Our studies resolve a 15-year long controversy by showing that pacemaker cells in the brain appear responsible for gasping but not normal breathing. Importantly, cot death has been proposed to result from a failure of autoresuscitation and gasping." Using a unique experimental set-up developed in Bristol, Paton combined forces with two other world leaders in respiration – Dr. Jeffrey Smith (NIH, USA) and Professor Walter St.-John (Dartmouth, USA) – to discover how gasping works. They found that many different types of brain cells are essential for normal breathing, but only a small subset of these is required for gasping or autoresuscitation. If normal breathing should stop, this backup system is activated to induce gasping. This restores oxygen supplies and kick-starts the heart beat so that normal breathing can resume.

Keyword: Sleep
Link ID: 8524 - Posted: 06.24.2010

A new study to examine facial preference, has found that people are attracted to facial characteristics indicative of personality traits similar to their own Biological scientists at the University of Liverpool launched the study to investigate the reasons why many couples tend to look similar to each other. The team, in collaboration with the University of Durham and the University of St Andrews, asked participants to judge perceived age, attractiveness, and personality traits of real-life married couples. Photographs of female faces were viewed separately to male faces, so that participants were unaware of who was married to whom. Dr Tony Little, from the University's School of Biological Sciences, explains: "There is widespread belief that couples, particularly those who have been together for many years, look similar to each other. To understand why this happens, we looked at the assumptions that people make about a person's personality, based on facial characteristics. We found that perceptions of age, attractiveness and personality were very similar between male and female couples. For example if the female face was rated as 'sociable' then her partner was also more likely to be rated as 'sociable.' "We also found that couples who had been married for a long period of time, were perceived as having more similar personalities than those who had not been together very long. This may come from sharing experiences together - affecting how their face appears."

Keyword: Sexual Behavior
Link ID: 8523 - Posted: 02.11.2006

Washington, D.C. — Based on laboratory research, scientists at Georgetown University Medical Center have a new theory as to why people with Alzheimer's disease have trouble performing even the simplest memory tasks, such as remembering a family member’s name. That’s because they discovered a physical link between apolipoprotein E (APOE), the transport molecules known to play a role in development of the disease, and glutamate, a brain chemical necessary for establishing human memory. In a study published in the Journal of Biological Chemistry, the research team specifically found that receptors on the outside of brain nerve cells (neurons) that bind on to APOE and glutamate are connected on the surface of neurons, separated from each other by only a small protein. While the researchers don’t know why these receptors are linked together, they say inefficient or higher-than-average levels of APOE in the brain could possibly be clogging these binding sites, preventing glutamate from activating the processes necessary to form memories. “We have found out that two receptors previously thought to have nothing to do with each other do, in fact, interact, leading us to conclude that APOE affects the NMDA glutamate channel that is important in memory,” says the study’s senior author, G. William Rebeck, PhD, associate professor of neuroscience in Georgetown’s Biomedical Graduate Research Organization.

Keyword: Alzheimers
Link ID: 8522 - Posted: 06.24.2010

Researchers have linked a hormone known to adjust levels of key brain chemicals to the quality of our hearing as we age. The more of the hormone that older people have in their bloodstream, the better their hearing is, and the less of the hormone, the worse their hearing is. The hormone, aldosterone, is known to regulate kidney function and also plays a role in controlling levels of two crucial signaling chemicals in the nervous system, potassium and sodium. For nerves to send signals crisply and work properly, potassium and sodium must be in precise proportion, without any disruption in the molecular channels or gates through which they move. Levels of potassium are particularly crucial in the sensitive inner ear, where fluid rich in potassium plays a central role in converting sounds into signals that the nervous system recognizes. The team of scientists in Rochester, N.Y., put 47 healthy men and women between the ages of 58 and 84 through a battery of sophisticated hearing tests. Scientists also measured their blood levels of aldosterone, which is known to drop as people age. They found that people with severe hearing loss had on average about half as much aldosterone in their bloodstream as their counterparts with normal hearing. The researchers noted, however, that the levels of aldosterone found in all the participants is considered normal, and that no patients or physicians should consider altering aldosterone levels without more research.

Keyword: Hearing; Hormones & Behavior
Link ID: 8521 - Posted: 02.11.2006

Bruce Bower The concept of identity theft assumes an entirely new meaning for people with brain injuries that rob them of their sense of self—the unspoken certainty that one exists as a person in a flesh—bounded body with a unique set of life experiences and relationships. Consider the man who, after sustaining serious brain damage, insisted that his parents, siblings, and friends had been replaced by look-alikes whom he had never met. Everyone close to him had become a familiar-looking stranger. Another brain-injured patient asserted that his physicians, nurses, and physical therapists were actually his sons, daughters-in-law, and coworkers. He identified himself as an ice skater whom he had seen on a television program. The sense of "I" can also go partially awry. After a stroke had left one of her arms paralyzed, a woman reported that the limb was no longer part of her body. She told a physician that she thought of the arm as "my pet rock." Other patients bequeath their physical infirmities to phantom children. For instance, a woman blinded by a brain tumor became convinced that it was her child who was sick and blind, although the woman had no children. Copyright ©2006 Science Service.

Keyword: Laterality; Attention
Link ID: 8520 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Female baboons that suffer the loss of a close friend or relative turn to other baboons for comfort and support, according to a new study that encompassed 14 years of observing over 80 free-ranging baboons in Botswana's Okavango Delta. The study provides the first direct evidence that certain animals mourn the loss of individuals, even when the rest of their social group remains intact. The findings also suggest that friendship may be just as important to some primates as it is for humans. Researchers particularly were struck by the behavior of one female chacma baboon (Papio hamadryas ursinus) named Sylvia, who was described as "the queen of mean" and disdainful of other baboons until she lost her daughter, Sierra, to a lion kill. "In the week after Sierra died, Sylvia was withdrawn," said Anne Engh, who led the project. "When the other females were grooming and socializing, she tended to sit alone and rarely interacted even with her other relatives." Copyright © 2006 Discovery Communications Inc.

Keyword: Emotions; Evolution
Link ID: 8519 - Posted: 06.24.2010

Prashant Nair TWO antibodies that enabled the severed spinal nerves of rats to be regenerated are to be tested in humans. The antibodies have helped rats with damaged spinal cords to walk again, by blocking the action of Nogo, a protein that stops nerve cells sprouting new connections. But there were concerns about whether blocking Nogo would lead to uncontrolled neuronal rewiring in the brain or spinal cord and it was also unclear how such a therapy could be given to humans. Now Martin Schwab and his colleagues at the University of Zurich in Switzerland have infused two antibodies, 11C7 and 7B12, into the damaged spinal cords of rats. An osmotic mini-pump connected to a fine catheter was used to deliver the antibodies directly into the cerebrospinal fluid surrounding the injured part of the spinal cord - a method of delivery that could easily be applied to humans, they say. The antibodies triggered regeneration of axons, the fine thread-like extensions that connect neurons, and enabled injured rats to swim, cross the rungs of a ladder without slipping and traverse a narrow beam (Annals of Neurology, vol 58, p 706). Moreover, the antibodies did not cause hyperalgesia, a condition in which even a simple touch is sensed as pain - a sign that would have indicated wrong neuronal connections had been made. © Copyright Reed Business Information Ltd.

Keyword: Regeneration
Link ID: 8518 - Posted: 06.24.2010

Roxanne Khamsi Colour vision may have evolved in primates to help them pick up on changes in blood and oxygen concentrations beneath the skin’s surface, giving access to emotional cues, a new analysis proposes. Previously research has suggested that primates – the only mammals with the ability to see in colour – evolved this facility to spot ripe fruits or nutritional leaves. The new analysis compared variations in skin colour change with the colour sensitivities of primate vision cells. These cells, known as cones, sit in the retina of the eye and allow primates to discriminate colour. Charting the receptivity of these cells was no small task. “Basically, careful retinal neurophysiologists and psychophysicists spent untold numbers of hours measuring how sensitive each cone is to each wavelength of light,” says Mark Changizi at Caltech in Pasadena, California, US. Changizi, who led the new study, and his colleagues built on this previous research by analysing how different primates’ cone cells might pick up on shifting blood oxygen levels, which show through the skin. © Copyright Reed Business Information Ltd

Keyword: Vision; Emotions
Link ID: 8517 - Posted: 06.24.2010

There is no evidence the hormone melatonin is effective in preventing jet lag or treating sleep disorders, research has found. Melatonin plays a role in controlling daily body rhythms, and has become popular in supplement form to treat sleep problems. The University of Alberta study suggests there is little evidence to support this. But UK experts have challenged the British Medical Journal study. Melatonin is produced naturally by the pineal gland in the brain. Research has shown that levels rise at night and fall in the morning. The researchers looked at the use of melatonin to treat people with 'secondary' sleep problems, often caused by medical or psychological conditions, or substance misuse They also assessed whether the hormone could help people with disturbed or restricted sleep, such as shift workers, or those with jet lag. In total, they examined data from 16 trials including more than 500 people. Melatonin had no significant impact - either on increasing amount of sleep, or reducing the time taken to fall asleep - among people with disturbed or restricted sleep. It did increase amount of sleep among people with secondary sleep problems. But the effect was so small - less than 10 minutes extra sleep in an eight-hour period spent in bed - that the researchers dismissed it as clinically unimportant. (C)BBC

Keyword: Biological Rhythms; Hormones & Behavior
Link ID: 8516 - Posted: 02.10.2006

Misfolded and damaged proteins are common to all human neurodegenerative diseases. Clumps of these aggregated proteins destroy neurons within the brain and cause disease. But explanations for the mechanism that actually causes cell death have varied widely, puzzling scientists and leading them to ask whether Alzheimer's, Parkinson's, Huntington's and Creutzfeldt-Jakob diseases and familial amyotrophic lateral sclerosis (ALS) are related diseases or very different diseases. Northwestern University scientists now offer a clue that may get to the core of the cell death question and establish a common mechanism in these diseases. In a study to be published online Feb. 9 by the journal Science, the research team shows that polyglutamine (the toxic component of the protein responsible for Huntington's disease) is so demanding on the cell's system that it changes the environment within the cell, causing other metastable, or partially folded, proteins to crash and lose function. Over time, this can cause the organism to die. "Our results suggest that these disease-associated, aggregation-prone proteins may exert their destabilizing effects by interfering generally with other proteins that are having difficulty folding," said Richard I. Morimoto, Bill and Gayle Cook Professor of Biochemistry, Molecular Biology and Cell Biology, who led the study. Morimoto is an expert in Huntington's disease and on the cellular and molecular response to damaged proteins.

Keyword: Parkinsons; Huntingtons
Link ID: 8515 - Posted: 02.10.2006

Falling in love can make us behave quite differently oddly. We'll give up all our worldly possessions, travel half way around the globe and completely change our lives to be with the people we love. A British king, Edward VIII, even gave up his throne for love. "You will do quite irrational things, or inventive things. You might even get up, and jump up and down on a couch," says neuroscientist Lucy L. Brown, from the Albert Einstein College of Medicine of Yeshiva University. Brown discovered that the intoxicating feeling of falling in love is not an emotion. It's a reward — produced by an unconscious brain system, much older than other systems and therefore considered essential to survival. This primitive reward system is shared by many animals and is similar to the one that motivates us to find food when we're hungry, or water when we're thirsty. "It suggests that the person we're in love with is a goal that we must have, just in the same way that we must have food or water," Brown says. "We can have varied emotions around love — happiness, anxiety, even anger sometimes — but the most important aspect of love is this core motivation that drives us." © ScienCentral, 2000-2006.

Keyword: Sexual Behavior; Drug Abuse
Link ID: 8514 - Posted: 06.24.2010

A Florida State University scientist used a gene transfer technique to block the expression of a gene associated with clinical depression in a new study of mice that could lead to better treatment of human beings with this condition. Carlos Bolanos, an assistant professor of psychology and neuroscience, was among a team of researchers that identified the role of a gene called Brain Derived Neurotrophic Factor (BDNF) in the development of social aversion. Mice treated with a transfer technique to block expression of the BDNF gene in a small area of the mid-brain did not develop the aversion despite repeated encounters with aggressive rodents. The study will be published in the Feb. 10 issue of the journal Science. "It's very exciting because we are slowly but surely identifying mechanisms in the brain underlying psychiatric disorders that have a social withdrawal component, such as social phobia, depression and post-traumatic stress disorder, and that will allow us to find better ways to treat these disorders," Bolanos said. "This study is significant because it gives us an animal model of the disorder and opens up new areas of study." In the experiment, the researchers subjected mice to daily bouts of social threats and subordination by aggressive rodents and continuous sensory contact with the aggressors for 10 days. Afterward, the defeated mice avoided any social contact by spending most of their time in the corner of their cages opposite other mice, including those that had not been aggressive toward them.

Keyword: Depression; Genes & Behavior
Link ID: 8513 - Posted: 02.10.2006

Helen Pearson A single genetic change can render mice immune to the consequences of hostile bullying, and this may point the way to drugs for social phobias and depression. Mice, somewhat like people, become withdrawn and unhappy when they are exposed to other, aggressive mice. Now a team led by Eric Nestler at the University of Texas Southwestern Medical Center in Dallas has exposed what is going on in the brains of these introverted animals. The researchers placed a small, brown mouse of one strain in a cage with a larger, white, aggressive mouse from another. "They're just naturally mean mice," Nestler says of the intimidating white strain. After ten daily bouts with a different tyrant, the brown mice seemed socially scarred. Even a month after the bullying sessions, normally gregarious animals clung to the corner of their cage, shying away from both white mice and familiar brown ones. The researchers showed that these social problems are controlled by a reward circuit in the brain that is known to tell the animals that food, sex and drugs are gratifying. They did this by taking a group of mice and removing a key protein called brain-derived neurotrophic factor (BDNF) from this reward circuit. Mice lacking BDNF were no longer browbeaten by the aggressive mice, they found. The researchers suggest that BDNF is needed for the animals to learn that bullying mice are very far from rewarding, and are actually horrible. ©2006 Nature Publishing Group

Keyword: Drug Abuse; Trophic Factors
Link ID: 8512 - Posted: 06.24.2010

Scientists hope a new drug could cut the risk of serious disability following a stroke. A trial, led by Glasgow University researchers, involving more than 1,700 patients in 154 hospitals worldwide has produced promising results. The treatment, known as NXY-059, works by minimising brain damage in the early hours after an clot-related stroke. Stroke is one of the most common causes of death and long-term disability around the world. A clot-related, or ischaemic, stroke is caused by a blockage in the blood vessels supplying the brain. It can cause symptoms including facial weakness, arm weakness and problems speaking. But it is estimated that under 1% of stroke patients in the UK currently receive drugs to reduce the risk of further clots. During the latest trial, patients were examined when they arrived at hospital within six hours of developing symptoms of a stroke. Half were given normal fluids through a drip, while the others received normal fluids and NXY-059. Lead researcher Professor Kennedy Lees said: "Patients who were given this new drug were more likely to have made a full recovery from stroke after three months." (C)BBC

Keyword: Stroke
Link ID: 8511 - Posted: 02.09.2006

By GARDINER HARRIS WASHINGTON, Feb. 8 — Twenty-five people died suddenly and 54 others suffered serious unexplained heart problems while taking stimulant drugs like Ritalin from 1999 through 2003, according to reports sent to federal drug regulators. It is impossible to determine whether the deaths and injuries resulted from the drugs or from other factors, federal drug regulators wrote in a 2004 report released publicly Wednesday. But stimulant drugs are among the most widely prescribed medicines in the world, and so any hint that they may cause health problems leads to intense concern. Few mental health experts believe that the drugs are dangerous. "Controlled trials have never found anything" suggesting that drugs to treat hyperactivity injure the heart, said Dr. Tom Insel, director of the National Institute of Mental Health. Children accounted for 19 of the deaths noted in the 2004 report and 26 of the serious heart problems, and the report, using the abbreviation for attention-deficit hyperactivity disorder, said, "The rare occurrence of pediatric sudden death during stimulant therapy of A.D.H.D. is an issue that warrants close monitoring." An advisory committee for the Food and Drug Administration will meet Thursday to discuss the report and recommend ways to research whether the drugs are to blame for the deaths. Copyright 2006 The New York Times Company

Keyword: ADHD; Development of the Brain
Link ID: 8510 - Posted: 06.24.2010

A new study of fossil foot bones across human history suggests that some of our very early ancestors had a rather peculiar way of walking. Anthropologists Dan Gebo of Northern Illinois University and Gary Schwartz of Arizona State University analyzed heel and anklebone casts of five separate species of human ancestors to understand how human walking changed over time. The study identifies the earliest foot bones belonging to the genus Homo, the same grouping of species that includes Homo sapiens, and highlights intriguing differences found among even earlier human ancestors. “Most people have argued that the foot bones of our human ancestors aren't all that different, but that's not the case,” said Gebo, a world authority on hominid foot bones. “The pattern of biomechanical changes that leads to the way modern humans walk today clearly took millions of years. “With the earlier species of human ancestors that we analyzed, it's clear that their feet didn't work exactly like ours. This implies subtle gait changes over time.” Gebo and Schwartz will report their findings in an upcoming edition of the American Journal of Physical Anthropology. ©PhysOrg.com 2003-2006

Keyword: Evolution
Link ID: 8509 - Posted: 06.24.2010

Researchers at the University of Illinois at Chicago have discovered that a long-approved oral antipsychotic drug can stop the addictive properties of opioid painkillers in mice. The researchers injected a small dose (half a milligram) of trifluoperazine -- used in the treatment of mental diseases such as schizophrenia -- into laboratory mice hooked on morphine. After a few hours their addiction was gone, said Z. Jim Wang, assistant professor of pharmacology in the UIC College of Pharmacy. This is the first time any study has shown the anti-addictive property of trifluoperazine, Wang said. "From studies conducted in the 1970s and 1980s, we know that trifluoperazine inhibits calmodulin," Wang said, a molecule that is required for the activation of an enzyme called calcium/calmodulin-dependent protein kinase-2. "In previous studies we performed at UIC, we know that CaMK-2 plays an important role in the generation and maintenance of opioid tolerance," he said. Tolerance is a hallmark of drug dependence. "Trifluoperazine targets this pathway, which then stops the addiction," Wang said. "When this occurs, you can still use a relatively low dose of the painkiller to achieve fairly good pain control and no drug dependence."

Keyword: Drug Abuse
Link ID: 8508 - Posted: 02.09.2006

Brain images of children with dyslexia taken before they received spelling instruction show that they have different patterns of neural activity than do good spellers when doing language tasks related to spelling. But after specialized treatment emphasizing the letters in words, they showed similar patterns of brain activity. These findings are important because they show the human brain can change and normalize in response to spelling instruction, even in dyslexia, the most common learning disability. The research is unique in that it looks at images of individual brains rather than the composite group images, or maps, that are typically produced to show which areas of the brain are activated when people are engaged in specific tasks. Being able to study how individual brains differ between good and poor spellers and how they normalize after receiving one of two treatments is an important advance, according to University of Washington neuroimaging scientist Todd Richards and neuropsychologist Virginia Berninger, who headed the research team. The new findings were published in the January issue of the journal Neurolinguistics. "Most people think dyslexia is a reading disorder, but it is also a spelling and writing problem," said Berninger, who directs the UW's Learning Disabilities Center. "Our results show that all dyslexics in the 9- to 12-year-old range have spelling problems and children who cannot spell cannot express their ideas in writing."

Keyword: Dyslexia
Link ID: 8507 - Posted: 02.09.2006

Roxanne Khamsi Prenatal exposure to certain antidepressants appears to increase a newborn’s risk of exhibiting drug withdrawal symptoms and respiratory abnormalities, according to two new studies. Researchers behind the studies urge doctors to carefully consider these findings before prescribing this type of medication to pregnant women. The use of SSRI antidepressants in pregnant women increased the risk of a respiratory disorder – persistent pulmonary hypertension (PPHN) – in the newborn by 600%. This was the finding of a new retrospective study which included 377 women whose infants had the disorder. SSRIs, or selective serotonin-reuptake inhibitors, work by increasing the availability of the chemical messenger serotonin in the body. Mothers of infants with PPHN were interviewed by Christina Chambers at the University of California, San Diego, US, and colleagues to determine how many of them used SSRIs during pregnancy. The team then compared this with the use of SSRIs among mothers of healthy babies. Their analysis showed that women using these antidepressants after the 20th week of gestation had a higher risk of giving birth to a baby with PPHN. This relatively rare respiratory disorder occurs in an estimated one to two infants per 1000 live births in the US. It is a dangerous condition and, despite treatment, 10% to 20% of affected newborns do not survive. © Copyright Reed Business Information Ltd

Keyword: Depression; Development of the Brain
Link ID: 8506 - Posted: 06.24.2010

By RANDAL C. ARCHIBOLD SANTA FE, N.M., Feb. 7 — Against the vivid backdrop of recent killings by mentally ill people, both sides in the national debate over whether mentally ill people who have not committed a crime can be forced into treatment are preparing for a showdown in the Legislature here. New Mexico lawmakers are considering a bill, backed by Gov. Bill Richardson, that would make the state the 43rd with a law allowing family members, doctors or others to seek a court order forcing the mentally ill into outpatient treatment. Typically under the laws, if mentally ill people refuse the treatment, they can face confinement in a hospital. Across the country, proponents have pushed the laws as a pragmatic approach to the mentally ill who fall through the cracks of the mental health system, particularly those who have committed no crime but could harm themselves or others as their sickness worsens. These mentally ill people often do not need to be in a hospital, but do need to stick to treatment, which could include medication, therapy or both. "We are talking about a small group of people who do not get help because they don't want help or know they need help," Mary T. Zdanowicz, executive director of the Treatment Advocacy Center, based in Virginia, said in a break from lobbying lawmakers here. Copyright 2006 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 8505 - Posted: 06.24.2010