Links for Keyword: Neuroimmunology

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By MOISES VELASQUEZ-MANOFF WHEN Andre H. Lagrange, a neurologist at Vanderbilt University in Nashville, saw the ominous white spots on the patient’s brain scan, he considered infection or lymphoma, a type of cancer. But tests ruled out both. Meanwhile, anti-epilepsy drugs failed to halt the man’s seizures. Stumped, Dr. Lagrange turned to something the mother of the 30-year-old man kept repeating. The fits coincided, she insisted, with spells of constipation and diarrhea. That, along with an odd rash, prompted Dr. Lagrange to think beyond the brain. Antibody tests, followed by an intestinal biopsy, indicated celiac disease, an autoimmune disorder of the gut triggered by the gluten proteins in wheat and other grains. Once on a gluten-free diet, the man’s seizures stopped; those brain lesions gradually disappeared. He made a “nearly complete recovery,” Dr. Lagrange told me. I began encountering case descriptions like this some years ago as I researched autoimmune disease. The first few seemed like random noise in an already nebulous field. But as I amassed more — describing seizures, hallucinations, psychotic breaks and even, in one published case, what looked like regressive autism, all ultimately associated with celiac disease — they began to seem less like anomalies, and more like a frontier in celiac research. They tended to follow a similar plot. What looked like neurological or psychiatric symptoms appeared suddenly. The physician ran through a diagnostic checklist without success. Drugs directed at the brain failed. Some clue suggestive of celiac disease was observed. The diagnosis was made. And the patient recovered on a gluten-free diet. The cases highlighted, in an unusually concrete fashion, the so-called gut-brain axis. The supposed link between the intestinal tract and the central nervous system is much discussed in science journals, often in the context of the microbial community inhabiting the gut. But it’s unclear how, really, we can leverage the link to improve health. © 2014 The New York Times Company

Related chapters from BN: Chapter 13: Homeostasis: Active Regulation of the Internal Environment; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment; Chapter 11: Emotions, Aggression, and Stress
Link ID: 20200 - Posted: 10.13.2014

Ian Sample, science editor Heartbreak can impair the immune system of older people and make them more prone to infections, researchers have found. Scientists said older people who had suffered a recent bereavement had poorer defences against bacteria, which could leave them more vulnerable to killer infections, such as pneumonia. Blood tests showed that the same group had imbalances in their stress hormones, which are known to have a direct impact on the body's ability to fight off bugs. Anna Phillips, a reader in behavioural medicine at Birmingham University, said the damaging effects of bereavement on the immune system were not seen in younger people, whose defences seemed more resilient. The finding suggests that in the weeks and months after the loss of a loved one, older people should keep in touch with their friends and family, and exercise and eat well, to reduce stress levels and boost their immune systems. "Bereavement is a really key stressor that happens to all of us at some point so it's worth being aware of the negative impact it can have on your health," Phillips said. "It's a key time to look after yourself in terms of your psychological and physical wellbeing. Don't try and cope by staying in, drinking more and exercising less. Try to cope by having social interactions, looking after yourself by keeping a certain level of fitness and eating well," she added. For her study, Phillips recruited people who had lost a loved one, either a spouse or family member, in the past two months. She then looked at how well bacteria-killing immune cells called neutrophils performed. © 2014 Guardian News and Media Limited

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 4: Development of the Brain
Link ID: 20058 - Posted: 09.10.2014

By Susan Milius Mice in the wild have no problem dining where someone else has pooped. Animals with higher standards of hygiene, reported in earlier studies, may not face the same dangers as small, hungry creatures scurrying around the woods. Feeding among feces of your own species raises the risk of catching nasty intestinal parasites, explains behavioral ecologist Patrick T. Walsh of University of Edinburgh. So far most tests of fecal avoidance have focused on hoofed animals. Horses, cows, sheep, reindeer and even wild antelopes tend not to graze in heavily poop-dotted areas. White-footed and deer mice, however, show no such daintiness of manners in a test in the woods, Walsh and his colleagues report in the September Animal Behaviour. Wild mice may have more immediate problems, like starvation or predators that domesticated--or just plain bigger--animals don’t. For the wild mice, Walsh says, fecal avoidance may be “a luxury.” Learning whether and when animals avoid poop helps clarify how parasites spread, an issue important for the health of both wildlife and people. So far no one has tested fecal avoidance for mice feeding in the lab, but research has shown that female lab mice tend to avoid the urine of parasite-infected males. To see whether mice in the wild dodge parasite risks, Amy Pedersen, a coauthor of the study also at Edinburgh, designed an experiment with a long plastic box divided into zones, some of which had mouse droppings in them. In the experiment, researchers tested more than 130 wild Peromyscus mice, of either the leucopus or maniculatus species, held captive for less than a day in the mountains of Virginia. © Society for Science & the Public 2000 - 2013

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 18635 - Posted: 09.12.2013

Maggie Fox NBC News A 12-year-old Arkansas girl infected with a brain-eating amoeba is on the mend and may be only the third person known to have survived the baffling infection, doctors said Wednesday. She’s recovering just as a 12-year-old boy in Miami struggles for his life with the same infection. Doctors note the infection is still extremely rare – so rare that health officials don’t know how to track it or protect against it. They’re also not sure why Kali Hardig of Little Rock appears to be recovering, but federal health officials are relaying details about her treatment to the team treating Zachary Reyna in Miami. The amoeba is called Naegleria fowleri, and it’s found in warm, fresh waters all over the world. It’s been seen in hot springs and swimming holes, freshwater lakes and even in neti pots used to clean out sinuses. It infects people through the nose, traveling up the nerve cells that carry smell signals into the brain. Doctors are not sure how or why a very few people are susceptible, but it’s clear that having water forced up into the sinuses, perhaps by dunking or diving, is an important factor. Kali became ill after swimming at a water park fed by spring water in Little Rock. Doctors at Arkansas Children’s Hospital tried the standard approach – a cocktail of four antibiotics – but also used an experimental antifungal drug and an unusual approach that involved lowering her body temperature.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 4: Development of the Brain
Link ID: 18510 - Posted: 08.15.2013

By Sandra G. Boodman, For someone who had been such a healthy child, Nancy Kennedy couldn’t figure out how she had become the kind of sickly adult whose life revolved around visits to a seemingly endless series of doctors. Beginning in 2005, shortly after a job transfer took her from Northern Virginia to St. Louis, Kennedy, then 47, developed a string of vexing medical problems. Her white blood cell count was inexplicably elevated. Her sinuses were chronically infected, although her respiratory tract seemed unusually dry. She often felt fatigued, and her joints hurt. “It felt as though an alien had invaded my body,” said Kennedy, formerly a manager at the National Geospatial-Intelligence Agency. “I felt like I was in doctors’ offices all the time.” Tests for possible ailments — including blood disorders, cancer, multiple sclerosis and rheumatoid arthritis — were negative. For seven years. Kennedy and her primary-care physician, who said she felt as though she sent Kennedy to “every specialist that walked,” had no clear idea what might be wrong. But during a physical in January 2012, her doctor, Melissa Johnson, struck by Kennedy’s trouble walking and her accelerating deterioration, decided to check for a condition not previously considered. © 1996-2013 The Washington Post

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 5: The Sensorimotor System
Link ID: 18040 - Posted: 04.16.2013

By Jon Lieff Traditionally, we have understood the immune system and the nervous system as two distinct and unrelated entities. The former fights disease by responding to pathogens and stimulating inflammation and other responses. The latter directs sensation, movement, cognition and the functions of the internal organs. For some, therefore, the recent discovery that left-sided brain lesions correlate with an increased rate of hospital infections is difficult to understand. However, other recent research into the extremely close relationship between these two systems makes this finding comprehensible. A study, published in the March 2013 issue of Archives of Physical Medicine and Rehabilitation, looked at more than 2,000 hospital patients with brain lesions from either stroke or traumatic brain injury. They looked at how many of these brain-injured patients contracted infections within 2 to 3 days of admission. Of those patients who developed infections, 60% had left-sided lesions. The authors concluded that an unknown left-sided brain/immune network might influence infections. But why would the left side of the brain affect immunity? The nervous and immune systems are quite different in their speed and mode of action. The two major immune systems, innate and adaptive, are both wireless—they communicate through cell-to-cell contact, secreted signals, and antigen-antibody reactions. The innate system is the first responder, followed by the slower adaptive response. The nervous system, on the other hand, is wired for much more rapid communication throughout the body. It turns out that the two work surprisingly closely together. © 2013 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Lateralization
Link ID: 17901 - Posted: 03.15.2013

Monya Baker Last week, the Sacramento Bee reported that two neurosurgeons at the University of California, Davis, had been banned from research on humans after deliberately infecting three terminally ill cancer patients with pathogenic bacteria in an attempt to treat them. All three died, two showing complications from the infection. Nature explores what happened and the science behind it. Who authorized the researchers to infect the patients? All three patients consented to infection. However, anyone testing experimental drugs in the United States requires approval from their university’s Institutional Review Board (IRB) and oversight by the country's Food and Drug Administration (FDA), both of which review evidence for safety and efficacy. Neurosurgeons Paul Muizelaar and Rudolph Schrot at the University of California (UC), Davis, did not obtain this approval; they say they did not think it was required. Harris Lewin, the vice-chancellor of research at UC Davis, wrote a letter to the FDA describing what had occurred as “serious and continuing noncompliance”. In 2008, working under instructions from Muizelaar, Schrot asked the FDA about the possibility of deliberately infecting a postoperative wound in a particular patient with glioblastoma with the bacterium Enterobacter aerogenes. He was told that animal studies were needed first. Muizelaar did not infect that patient, but arranged for a graduate student to begin tests in rats. Although bacteria were purchased as research materials not to be used in humans, they were eventually used in three other patients with glioblastoma. © 2012 Nature Publishing Group

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17097 - Posted: 07.28.2012

By Lauren F. Friedman More than 100 years ago Ivan Pavlov famously observed that a dog salivated not only when fed but also on hearing a stimulus it associated with food. Since then, scientists have discovered many other seemingly autonomous processes that can be trained with sensory stimuli—including, most recently, our immune system. Researchers have long been able to train an animal’s immune system to respond to a nonpathogen stimulus. Pavlov’s students even did so in the early 20th century, but the famous dogs overshadowed their work. Then, in the 1970s, researchers trained rats and mice to associate a taste, such as sugar water, with an immunosuppressive drug. They found that after repeated conditioning, ingest­-ing the sugar water alone could tamp down the animals’ immune response. In 2002 a small study showed that the effect could be replicated in humans—at least on a onetime basis. By then, this training had already been used to prolong the survival of rats with heart transplants and slow the progression of lupus, arthritis and other autoimmune disorders in lab animals. But could human immune systems be trained to mimic a drug again and again? “If it can be done only once, that’s a very nice phenom­enon for understanding the relation between the brain and the immune system,” says Manfred Schedlowski, a medical psychologist at the University of Duisberg-Essen in Germany and a co-author of the 2002 paper. “But that’s clinically useless.” Last year Schedlowski published a study in the journal Brain, Behavior, and Immunity that aimed to find out whether the trained immunosuppressive response in humans could be sustained. © 2012 Scientific American,

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 16229 - Posted: 01.09.2012

By Rachel Ehrenberg Cockroaches may be nasty bugs, but they could help fight even nastier ones. New research finds that the rudimentary brains of cockroaches and locusts teem with antimicrobial compounds that slay harmful E. coli and MRSA, the antibiotic-resistant staph bacterium. The work could lead to new compounds for fighting infectious diseases in humans. Extracts of ground-up brain and other nerve tissue from the American cockroach, Periplaneta americana, and desert locust, Schistocerca gregaria, killed more than 90 percent of a type of E. coli that causes meningitis, and also killed methicillin-resistant staph, microbiologist Simon Lee reported September 7 at the Society for General Microbiology meeting at the University of Nottingham in England. “Some of these insects live in the filthiest places ever known to man,” says Naveed Khan, coauthor of the new study. “These insects crawl on dead tissue, in sewage, in drainage areas. We thought, 'How do they cope with all the bacteria and parasites?’” Khan and his colleagues became intrigued by insect antimicrobials when they noticed that many soldiers were returning from the Middle East with unusual infections, yet locusts living in the same areas were unperturbed. So the researchers, all from the University of Nottingham, began investigating how the insects ward off disease. The team ground up various body parts from both cockroaches and locusts that had been reared in the lab and incubated them for two hours with different bacteria. Leaving these mixtures overnight on petri dishes revealed that the extracts from brains and from locust thorax nerve tissue killed nearly 100 percent of the bacteria. © Society for Science & the Public 2000 - 2010

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14444 - Posted: 09.11.2010

By DAVID TULLER For decades, people suffering from chronic fatigue syndrome have struggled to convince doctors, employers, friends and even family members that they were not imagining their debilitating symptoms. Skeptics called the illness “yuppie flu” and “shirker syndrome.” But the syndrome is now finally gaining some official respect. The Centers for Disease Control and Prevention, which in 1999 acknowledged that it had diverted millions of dollars allocated by Congress for chronic fatigue syndrome research to other programs, has released studies that linked the condition to genetic mutations and abnormalities in gene expression involved in key physiological processes. The centers have also sponsored a $6 million public awareness campaign about the illness. And last month, the C.D.C. released survey data suggesting that the prevalence of the syndrome is far higher than previously thought, although these findings have stirred controversy among patients and scientists. Some scientists and many patients remain highly critical of the C.D.C.’s record on chronic fatigue syndrome, or C.F.S. But nearly everyone now agrees that the syndrome is real. “People with C.F.S. are as sick and as functionally impaired as someone with AIDS, with breast cancer, with chronic obstructive pulmonary disease,” said Dr. William Reeves, the lead expert on the illness at the C.D.C., who helped expose the centers’ misuse of chronic fatigue financing. Copyright 2007 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 10499 - Posted: 06.24.2010

CHAPEL HILL -- Taking care of chronically ill loved ones over long periods stresses caregivers, as everyone knows, but a new study provides strong new evidence that such continuing stress boosts the risk of age-related diseases by prematurely aging caregivers' immune systems. Levels of a damaging compound known as a proinflammatory cytokine not only increased considerably faster among those taking care of ailing spouses but also continued to increase faster for years after the spouses died. A report on the research, conducted by scientists at Ohio State University and the University of North Carolina at Chapel Hill, will appear online Monday afternoon (June 30) in the Proceedings of the National Academy of Sciences.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 3974 - Posted: 06.24.2010

Feeling depressed and fatigued does not increase a person's risk for cancer, according to a new study. Severely exhausted people, however, do engage in behavior that is associated with a higher cancer risk. The study, published in the September 15, 2005 issue of CANCER (http:/www.interscience.wiley.com/cancer-newsroom), a peer-reviewed journal of the American Cancer Society, is the first prospective study using the "vital exhaustion" questionnaire to investigate this link. The concept of vital exhaustion – described as feelings of excessive fatigue and lack of energy, increased irritability and a feeling of demoralization – grew out of the field of cardiology. Studies have identified vital exhaustion as a risk factor for heart attacks and death from a heart attack. Depressive mood has also been widely blamed, at least in lay literature, as a risk factor for cancer. However, the scientific data is much more inconsistent than that for heart attacks. Two recent prospective studies failed to identify a link between depression and cancer. Corinna Bergelt, Ph.D. of the Danish Cancer Society's Institute of Cancer Epidemiology in Copenhagen and colleagues followed 8527 people aged 21–94 years to investigate whether depressive feelings and exhaustion were risk factors for cancer, looking at all cancers combined, smoking-related cancers, alcohol-related cancers, virus and immune-related cancers, and hormone-related cancers.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 7745 - Posted: 06.24.2010

COLUMBUS, Ohio – A new study in mice suggests that, in certain cases, stress may enhance the body's ability to fight the flu. Short bouts of intense social stress improved the ability in the mice to recover from the flu. The stress apparently did so by substantially boosting the production of specialized immune cells that fought the virus. "Stressed mice had a stronger immune response and were able to fight off the infection faster," said Jacqueline Wiesehan, a study co-author and a graduate fellow in oral biology at Ohio State University. These special immune cells are called T cells and are part of the immune system's memory response. T cells "remember" specific infectious agents and can launch future attacks against these intruders. The researchers hope to learn more about the mechanisms behind the memory response, and to use this information to develop more effective flu vaccines in the future, said David Padgett, a study co-author and an associate professor of oral biology at Ohio State. Wiesehan, Padgett and John Sheridan, the study's lead author and a professor of oral biology at Ohio State, presented their findings on April 3 at the Experimental Biology 2005 conference in San Diego. The three also worked on this study with Michael Bailey, a postdoctoral fellow in oral biology at Ohio State.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 7134 - Posted: 06.24.2010

There is no association between two specific personality traits – neuroticism and extroversion – and cancer, according to a new study, one of the largest prospective twin studies to examine this issue. The study, published in the March 1, 2005 issue of CANCER (http://www.interscience.wiley.com/cancer-newsroom), a peer-reviewed journal of the American Cancer Society, also finds no evidence that personality traits indirectly lead to cancer through behavioral factors, such as smoking. Personality traits are popularly cited as risk factors for cancer. Some studies have gone so far as to suggest that two traits in particular, neuroticism and extroversion, may be such risk factors. Scientists have hypothesized that a high degree of extroversion and low degree of neuroticism are associated with an increased risk. Some studies further show that these personality traits influence known risk behaviors that would explain the increased cancer risk. However, other studies, some with larger study populations and better study designs, have found no such associations. Pernille Hansen, M.A. of the Department of Psychosocial Cancer Research at the Institute of Cancer Epidemiology in Copenhagen, Denmark led a team of investigators who reviewed cancer history, health behavior, and personality trait data collected from 29,595 Swedish twins enrolled in the Swedish Twin Registry. These patients were born between 1926-1958 and were followed an average 25 years

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 6738 - Posted: 06.24.2010

COLUMBUS, Ohio – A new study suggests that wounds on mice that prefer multiple mates heal at the same rate, whether the mice are housed with a mate or live in isolation. But the same doesn't ring true for monogamous mice, said Courtney DeVries, an assistant professor of psychology and neuroscience at Ohio State University. She and Erica Glasper, a doctoral student in psychology at Ohio State, took a closer look at the effects social bonding had on wound healing in monogamous and non-monogamous deer mice. Non-monogamous males mate with more than one female during a breeding season. The researchers especially wanted to see if social interaction, or the lack of it, made a difference in the rate of wound healing in the non-monogamous mice. It didn't. In fact, levels of corticosterone – a stress hormone that rodents secrete – in the non-monogamous mice were the same whether they were paired or alone, and were also significantly lower than the corticosterone levels of paired, monogamous mice.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 8: Hormones and Sex
Link ID: 5940 - Posted: 06.24.2010

By JANE E. BRODY If you have ever slept on an arm and awakened with a “dead” hand, or sat too long with your legs crossed and had your foot fall asleep, you have some inkling of what many people with peripheral neuropathy experience day in and day out, often with no relief in sight. And numbness and tingling are hardly the worst symptoms of this highly variable condition, which involves damage to one or more of the myriad nerves outside the brain and spinal cord. Effects may include disabling pain, stinging, swelling, burning, itching, muscle weakness, twitching, loss of sensation, hypersensitivity to touch, lack of coordination, difficulty breathing, digestive disorders, dizziness, impotence, incontinence, and even paralysis and death. I realize now that I had a mild, reversible bout of peripheral neuropathy several decades ago when a misplaced shot of morphine damaged a sensory nerve in my thigh. It took three years for the nerve to recover, and for much of that time I could not tolerate anything brushing against my leg. One of my sons, too, was afflicted when a nerve behind his knee was injured during a basketball game. He had no feeling or mobility in his foot for nine months, but after several years the nerve healed and he regained full use of his foot. And a good friend was nearly paralyzed, also temporarily, following a flu shot, by a far more serious form of peripheral neuropathy — an autoimmune affliction called Guillain-Barr syndrome, in which one’s own antibodies attack the myelin sheath that protects nerves throughout the body. Copyright 2009 The New York Times Company

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 13378 - Posted: 06.24.2010

Researchers have discovered a communications “hot line” that lets a worm's nervous system dial the immune system to help coordinate the response to infectious pathogens. The new research is the first to identify direct evidence that specific cells in the nervous system coordinate initial defenses against toxic bacteria. Those first responders are part of the innate immune system, a kind of “sixth sense” that is hard-wired and fends off invading microbes until the adaptive immune response is mobilized. “It has been recognized for at least 20 years that there must be bidirectional communication between the nervous and the immune systems,” says Alejandro Aballay at Duke University Medical Center. “But because of the complexity of the communication network it has been very difficult to prove this connection conclusively. The complexity of the nervous and immune systems of mammals, including humans, makes sorting out neural-immune communications a daunting task.” To cut through this complexity, Aballay and his colleagues turned to the simple roundworm, C. elegans. It proved to be an ideal model for dissecting those elusive connections—and for bringing together a diverse research team whose only connection was a signaling protein known primarily for its effect on the social life of worms. The research team included Aballay, Howard Hughes Medical Institute (HHMI) investigator Cornelia Bargmann at the Rockefeller University, as well as Sarah Steele, an undergraduate research student funded by an HHMI science education grant to Duke. The research is reported in the September 18, 2008 edition of Science Express, which provides electronic publication of selected Science papers. © 2008 Howard Hughes Medical Institute.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 12060 - Posted: 06.24.2010

Ewen Callaway A study showing how HIV could prevent the brain from making new neurons offers an explanation for why some AIDS patients get dementia — and suggests a possible treatment. Dementia due to HIV is the leading cause of cognitive decline in people under 40 years of age, says Stuart Lipton, a biologist at the Burnham Institute for Medical Research in La Jolla, California, who led the study in Cell Stem Cell1. Researchers aren't sure what causes the condition, which afflicts 10-30% of people with HIV and causes symptoms including forgetfulness and leg weakness. If untreated with antiretroviral drugs, sufferers can turn comatose. Biologists have two theories to explain AIDS-related dementia. It could be that when HIV infects a type of white blood cell called a macrophage, the cell pumps out inflammatory chemicals to battle the infection that also, unfortunately, wipe out neurons. Or HIV could inflict its damage more directly. One previous study showed that a protein in the virus's shell — called gp120 — can stop brain stem cells from dividing2. Such new stem cells are needed to make new neurons. To investigate, Lipton and postdoc Shu-ichi Okamoto studied a strain of mice genetically engineered to make the virus's gp120 protein. Under the microscope, the mouse brains look just like those of humans with AIDS-related dementia, says Lipton. ©2007 Nature Publishing Group

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 11: Emotions, Aggression, and Stress
Link ID: 10607 - Posted: 06.24.2010

PITTSBURGH—Happiness and other positive emotions play an even more important role in health than previously thought, according to a study published in the journal Psychosomatic Medicine by Carnegie Mellon University Psychology Professor Sheldon Cohen. The paper will be available online at www.psychosomaticmedicine.org/. This recent study confirms the results of a landmark 2004 paper in which Cohen and his colleagues found that people who are happy, lively, calm or exhibit other positive emotions are less likely to become ill when they are exposed to a cold virus than those who report few of these emotions. In that study, Cohen found that when they do come down with a cold, happy people report fewer symptoms than would be expected from objective measures of their illness. In contrast, reporting more negative emotions such as depression, anxiety and anger was not associated with catching colds. That study, however, left open the possibility that the greater resistance to infectious illness among happier people may not have been due to happiness, but rather to other characteristics that are often associated with reporting positive emotions such as optimism, extraversion, feelings of purpose in life and self-esteem. Cohen's recent study controls for those variables, with the same result: The people who report positive emotions are less likely to catch colds and also less likely to report symptoms when they do get sick. This held true regardless of their levels of optimism, extraversion, purpose and self-esteem, and of their age, race, gender, education, body mass or prestudy immunity to the virus.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 9592 - Posted: 06.24.2010

WASHINGTON — Underscoring the value of good prenatal care, new research suggests that early infection may create a cognitive vulnerability that appears later during stress on the immune system. Researchers at the University of Colorado at Boulder have reported that rats who experienced a one-time infection as newborns didn’t learn as well as adult rats who were not infected as pups, after their immunity was challenged. The research is in February’s Behavioral Neuroscience, published by the American Psychological Association (APA). The findings fit into a growing body of evidence that even a one-time infection can potentially permanently change physiological systems, a phenomenon called “perinatal programming.” Understanding how infection in newborns can disrupt memory in immune-challenged adults may help scientists to understand how exposure to germs or environmental stressors before or just after birth may foster susceptibility to neuropsychiatric and neurodegenerative diseases. For example, prenatal viral infection has been implicated in schizophrenia, autism and cerebral palsy; bacterial infection is a risk factor for Parkinson’s disease. Up to 20 percent of pregnancies have complications involving infections of the uterus and its contents, a number that will rise as more children are born premature. © 2005 American Psychological Association

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory and Learning
Link ID: 6821 - Posted: 06.24.2010