Links for Keyword: Neuroimmunology

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Diana Kwon The brain is the body’s sovereign, and receives protection in keeping with its high status. Its cells are long-lived and shelter inside a fearsome fortification called the blood–brain barrier. For a long time, scientists thought that the brain was completely cut off from the chaos of the rest of the body — especially its eager defence system, a mass of immune cells that battle infections and whose actions could threaten a ruler caught in the crossfire. In the past decade, however, scientists have discovered that the job of protecting the brain isn’t as straightforward as they thought. They’ve learnt that its fortifications have gateways and gaps, and that its borders are bustling with active immune cells. A large body of evidence now shows that the brain and the immune system are tightly intertwined. Scientists already knew that the brain had its own resident immune cells, called microglia; recent discoveries are painting more-detailed pictures of their functions and revealing the characteristics of the other immune warriors housed in the regions around the brain. Some of these cells come from elsewhere in the body; others are produced locally, in the bone marrow of the skull. By studying these immune cells and mapping out how they interact with the brain, researchers are discovering that they play an important part in both healthy and diseased or damaged brains. Interest in the field has exploded: there were fewer than 2,000 papers per year on the subject in 2010, swelling to more than 10,000 per year in 2021, and researchers have made several major findings in the past few years. No longer do scientists consider the brain to be a special, sealed-off zone. “This whole idea of immune privilege is quite outdated now,” says Kiavash Movahedi, a neuroimmunologist at the Free University of Brussels (VUB). Although the brain is still seen as immunologically unique — its barriers prevent immune cells from coming and going at will — it’s clear that the brain and immune system constantly interact, he adds (see ‘The brain’s immune defences’). © 2022 Springer Nature Limited

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 28344 - Posted: 06.01.2022

By Lisa Sanders, M.D. “You have to take your husband to the hospital right now,” the doctor urged over the phone. “His kidneys aren’t working at all, and we need to find out why.” The woman looked at her 82-year-old spouse. He was so thin and pale. She thanked the doctor and called 911. For the past couple of months, every meal was a struggle. Swallowing food was strangely difficult. Liquids were even worse. Whatever he drank seemed to go down the wrong pipe, and he coughed and sputtered after almost every sip. It was terrifying. He saw an ear, nose and throat specialist, who scoped his mouth and esophagus. There wasn’t anything blocking the way. The doctor recommended that he get some therapy to help him strengthen the muscles he used to swallow, and until he did that, he should thicken his liquids to make drinking easier. The patient tried that once, but it was so disgusting he gave up on it. His wife was worried as she watched him eat and drink less and less. She could see that he was getting weaker every day. He had a stroke four months earlier, and since then his right foot dragged a little. But now she had to help him get out of his recliner. And he wasn’t able to drive — she had to make the 45-minute trip with him each day to his office. Finally, he agreed to see Dr. Richard Kaufman, their primary-care doctor. Kaufman was shocked by the man’s appearance, how the skin on his face hung in folds as if air had been let out of his cheeks. He’d lost nearly 40 pounds. He struggled to walk the few steps to the exam table. His right side, which was weakened by his stroke, was now matched by weakness on his left side. His stroke hadn’t done this. There was something else going on. Kaufman ordered some preliminary blood tests to try to see where the problem might lie. Those were the results that sent the couple to the emergency room. © 2022 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 5: The Sensorimotor System
Link ID: 28339 - Posted: 05.28.2022

By Laura Sanders A tussle with COVID-19 can leave people’s brains fuzzy. SARS-CoV-2, the virus behind COVID-19, doesn’t usually make it into the brain directly. But the immune system’s response to even mild cases can affect the brain, new preliminary studies suggest. These reverberating effects may lead to fatigue, trouble thinking, difficulty remembering and even pain, months after the infection is gone. It’s not a new idea. Immune systems gone awry have been implicated in cognitive problems that come with other viral infections such as HIV and influenza, with disorders such as myalgic encephalomyelitis/chronic fatigue syndrome, or ME/CFS, and even from the damaging effects of chemotherapy. What’s different with COVID-19 is the scope of the problem. Millions of people have been infected, says neurologist Avindra Nath of the National Institutes of Health in Bethesda, Md. “We are now faced with a public health crisis,” he says. Sign up for e-mail updates on the latest coronavirus news and research To figure out ways to treat people for the fuzzy thinking, headaches and fatigue that hang around after a bout with COVID-19, scientists are racing to figure out what’s causing these symptoms (SN: 4/27/21). Cognitive neurologist Joanna Hellmuth at the University of California, San Francisco had a head start. As someone who had studied the effects of HIV on the brain, she quickly noted similarities in the neurological symptoms of HIV and COVID-19. The infections paint “the same exact clinical picture,” she says. HIV-related cognitive symptoms have been linked to immune activation in the body, including the brain. “Maybe the same thing is happening in COVID,” Hellmuth says. © Society for Science & the Public 2000–2022.

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: 28189 - Posted: 02.05.2022

Esther Landhuis Dogs that habitually hear a bell at chow time become classically conditioned to drool at the mere chime, as the physiologist Ivan Pavlov showed in the 1890s: Their brains learn to associate the bell with food and instruct the salivary glands to respond accordingly. More than a century later, in a paper published today in Cell, the neuroimmunologist Asya Rolls has shown that a similar kind of conditioning extends to immune responses. Using state-of-the-art genetic tools in mice, her team at the Technion in Haifa, Israel, identified brain neurons that became active during experimentally induced inflammation in the abdomen. Later, the researchers showed that restimulating those neurons could trigger the same types of inflammation again. “This is an outstanding body of work,” said Kevin Tracey, a neurosurgeon and president of the Feinstein Institutes for Medical Research in Manhasset, New York. It “establishes that the classic concept of immunological memory can be represented in neurons.” Others before Rolls have suggested that the brain could remember and retrieve immune responses, he said, but “she proved it.” Abstractions navigates promising ideas in science and mathematics. Journey with us and join the conversation. Ruslan Medzhitov, an immunologist at the Yale School of Medicine in New Haven, Connecticut, considers the new research “very provocative.” But unlike other groundbreaking studies that push boundaries and challenge conventional concepts, he said that this one also evokes “the ‘Oh, it makes sense’ type of reaction.” All Rights Reserved © 2021

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 28071 - Posted: 11.13.2021

By Raleigh McElvery While the brain and spinal cord have their own squad of specialized immune cells, the peripheral immune system is armed with a larger battalion of proteins, cells and entire organs, such as the spleen, that ward off invaders. Over the past decade, researchers have made great progress in understanding how the peripheral immune system affects neural activity: how immune signals that originate outside the central nervous system can affect cognitive processes, social behavior, neurodegeneration, and more. In fact, they have learned that immune cells from the periphery routinely patrol the central nervous system and support its function. In a new study, researchers showed for the first time that—just as the brain remembers people, places, smells, and so on—it also stores what they call “memory traces” of the body’s past infections. Reactivating the same brain cells that encode this information is enough to swiftly summon the peripheral immune system to defend at-risk tissues. In some ways, this is not an entire surprise. It is clear the peripheral immune system is capable of retaining information about past infections to fight off future ones—otherwise, vaccines would not work. But Asya Rolls, a neuroimmunologist at Technion–Israel Institute of Technology and the paper’s senior author, says the study expands this concept of classical immunologic memory. Initially, she was taken aback that the brain could store traces of immune activity and use them to trigger such a precise response. “I was amazed,” she says. Rolls’s team focused on a brain region called the insular cortex, which senses the body’s internal state through visceral signals such as temperature, pain, hunger and—the researchers reasoned—perhaps immune activity. They studied strains of mice with a type of gut inflammation known as colitis and used fluorescent markers to take snapshots of the groups of brain cells in the insular cortex that became active during the infection. © 2021 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 28069 - Posted: 11.09.2021

Linda Geddes Science correspondent Fibromyalgia – a poorly understood condition that causes widespread pain throughout the body and extreme tiredness – may be caused by be an autoimmune response that increases the activity of pain-sensing nerves throughout the body. The findings, published in the Journal of Clinical Investigation, challenge the widely held view that the condition originates in the brain, and could pave the way for more effective treatments for the millions of people affected. They could also have implications for patients suffering from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and “long Covid”. “These different syndromes are symptomatically very similar, so I think it could be very relevant to both of these conditions,” said Dr David Andersson from the Institute of Psychiatry, Psychology and Neuroscience at King’s College London, who led the new study. Fibromyalgia affects at least 1 in 40 people worldwide, although some estimates suggest nearly 1 in 20 people may be affected to some degree. It is characterised by widespread pain and crippling fatigue – often referred to as “fibro fog” – and usually develops between the ages of 25 and 55, although children can also get it. Similar to many autoimmune conditions, the vast majority of those affected (80% are women). Current treatment tends to focus on gentle aerobic exercise, as well as drug and psychological therapies designed to manage pain. However, these have proven ineffective in most patients and have left behind an enormous unmet clinical need, said Andersson. “The widespread paradigm at the moment is that this is a disease that emanates from the brain, and I think our findings suggest that that’s not the case,” he said. © 2021 Guardian News & Media Limited

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 27888 - Posted: 07.03.2021

Elena Renken A hundred years ago, the Japanese scientist Y. Shirai published a mysterious finding: When Shirai transplanted tumor tissue into a mouse’s body, the tissue was destroyed by its immune system. But when tumors were grafted in various places in the mouse’s brain, they grew. Tumors seemed to be able to safely hide in the brain, escaping the immune system’s notice. Similar results soon piled up, and scientific consensus accepted the brain as having “immune privilege” — a kind of separation from the immune system. This notion made some sense. Immune cells, in the course of fighting infections, can damage or destroy healthy tissue. Protecting neurons from this damage is more crucial than protecting cells like those in the liver or skin, because neurons typically can’t regenerate. “If they die, they die,” said Justin Rustenhoven, an immunologist at Washington University in St. Louis. “We have a very poor ability to replace them.” In the last couple of decades, though, the idea of immune privilege has withered in the face of mounting evidence that the brain and the immune system do interact. Researchers have tracked immune cells crossing from the bloodstream into the nervous system in animals with brain disease, for instance, and they’ve observed cognitive deficits in mice that lack certain immune cells. Now, Rustenhoven and collaborators have identified how evolution achieves a balancing act, limiting the dangers of immune responses in the central nervous system while still providing protection from disease. The researchers reported recently in the journal Cell that the immune system operates from a distance to constantly inspect the brain for signs of trouble. Immune cells, rather than making themselves at home throughout the brain itself, patrol the sidelines until they detect a threat. All Rights Reserved © 2021

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27799 - Posted: 05.01.2021

The membranes surrounding our brains are in a never-ending battle against deadly infections, as germs constantly try to elude watchful immune cells and sneak past a special protective barrier called the meninges. In a study involving mice and human autopsy tissue, researchers at the National Institutes of Health and Cambridge University have shown that some of these immune cells are trained to fight these infections by first spending time in the gut. “This finding opens a new area of neuroimmunology, showing that gut-educated antibody-producing cells inhabit and defend regions that surround the central nervous system,” said Dorian McGavern, Ph.D., senior investigator at NINDS and co-senior author of the study, which was published in Nature. The central nervous system (CNS) is protected from pathogens both by a three-membrane barrier called the meninges and by immune cells within those membranes. The CNS is also walled off from the rest of the body by specialized blood vessels that are tightly sealed by the blood brain barrier. This is not the case, however, in the dura mater, the outermost layer of the meninges. Blood vessels in this compartment are not sealed, and large venous structures, referred to as the sinuses, carry slow moving blood back to the heart. The combination of slow blood flow and proximity to the brain requires strong immune protection to stop potential infections in their tracks. “The immune system has invested heavily in the dura mater,” said Dr. McGavern. “The venous sinuses within the dura act like drainage bins, and, consequently, are a place where pathogens can accumulate and potentially enter the brain. It makes sense that the immune system would set up camp in this vulnerable area.”

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 27569 - Posted: 11.07.2020

Ashley Yeager Tiroyaone Brombacher sat in her lab at the University of Cape Town watching a video of an albino mouse swimming around a meter-wide tub filled with water. The animal, which lacked an immune protein called interleukin 13 (IL-13), was searching for a place to rest but couldn’t find the clear plexiglass stand that sat at one end of the pool, just beneath the water’s surface. Instead, it swam and swam, crisscrossing the tub several times before finally finding the platform on which to stand. Over and over, in repeated trials, the mouse failed to learn where the platform was located. Meanwhile, wildtype mice learned fairly quickly and repeatedly swam right to the platform. “When you took out IL-13, [the mice] just could not learn,” says Brombacher, who studies the intersection of psychology, neuroscience, and immunology. Curious as to what was going on, Brombacher decided to dissect the mice’s brains and the spongy membranes, called the meninges, that separate neural tissue from the skull. She wanted to know if the nervous system and the immune system were communicating using proteins such as IL-13. While the knockout mice had no IL-13, she reported in 2017 that the meninges of wildtype mice were chock full of the cytokine. Sitting just outside the brain, the immune protein did, in fact, seem to be playing a critical role in learning and memory, Brombacher and her colleagues concluded. As far back as 2004, studies in rodents suggested that neurons and their support cells release signals that allow the immune system to passively monitor the brain for pathogens, toxins, and debris that might form during learning and memory-making, and that, in response, molecules of the immune system could communicate with neurons to influence learning, memory, and social behavior. Together with research on the brain’s resident immune cells, called microglia, the work overturned a dogma, held since the 1940s, that the brain was “immune privileged,” cut off from the immune system entirely. © 1986–2020 The Scientist.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27540 - Posted: 10.21.2020

By Christa Lesté-Lasserre The bacteria that live in our bodies, particularly our guts, play key roles in immunity and development. But babies born by cesarean section don’t get the rich blend of microbes that come from a vaginal birth—microbes that may help prevent disorders such as asthma and allergies. Now, a study suggests feeding these infants a small amount of their mothers’ feces could “normalize” their gut microbiome—the ecosystem of bacteria, viruses, and fungi in the digestive system—and possibly give their immune systems a healthier start. Newborns’ guts are blank slates: Babies born vaginally get microbes from their mother’s perineum (the area around the vulva and anus), and those born by C-section get them from mom’s skin. Within just a few hours, the differences are stark. For example, Bacteroides and Bifidobacteria bacteria are abundant in the guts of babies born vaginally, but “almost absent in C-section babies,” says Willem de Vos, a microbiome scientist at the University of Helsinki. Because babies born by C-section have higher rates of immune-related disorders later in life, researchers think this early-life bacteria could “prime” the immune system during a critical development period. To lessen the damage, previous studies have “seeded” C-section babies with their mothers’ vaginal microbiota. But when those efforts didn’t seem to do the trick, de Vos and colleagues theorized that vaginally born babies might get their microbes from accidentally ingesting a smidgen of their mother’s stool during the birthing process. So they recruited 17 mothers preparing to give birth via C-section. Three weeks before the women were to give birth, their fecal samples were scanned for pathogens including group B Streptococcus and herpesvirus. © 2020 American Association for the Advancement of Science.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 27502 - Posted: 10.03.2020

By Apoorva Mandavilli The coronavirus targets the lungs foremost, but also the kidneys, liver and blood vessels. Still, about half of patients report neurological symptoms, including headaches, confusion and delirium, suggesting the virus may also attack the brain. A new study offers the first clear evidence that, in some people, the coronavirus invades brain cells, hijacking them to make copies of itself. The virus also seems to suck up all of the oxygen nearby, starving neighboring cells to death. It’s unclear how the virus gets to the brain or how often it sets off this trail of destruction. Infection of the brain is likely to be rare, but some people may be susceptible because of their genetic backgrounds, a high viral load or other reasons. “If the brain does become infected, it could have a lethal consequence,” said Akiko Iwasaki, an immunologist at Yale University who led the work. The study was posted online on Wednesday and has not yet been vetted by experts for publication. But several researchers said it was careful and elegant, showing in multiple ways that the virus can infect brain cells. Scientists have had to rely on brain imaging and patient symptoms to infer effects on the brain, but “we hadn’t really seen much evidence that the virus can infect the brain, even though we knew it was a potential possibility,” said Dr. Michael Zandi, consultant neurologist at the National Hospital for Neurology and Neurosurgery in Britain. “This data just provides a little bit more evidence that it certainly can.” Dr. Zandi and his colleagues published research in July showing that some patients with Covid-19, the illness caused by the coronavirus, develop serious neurological complications, including nerve damage. © 2020 The New York Times Company

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: 27469 - Posted: 09.12.2020

By Lucy Hicks “Social distancing” has become one of the buzz phrases of the year. But it turns out humans aren’t the only animals that put some space between themselves and others to reduce the transmission of disease. Wildlife—from finches to mandrills—use similar tactics, according to a paper published this week in the Proceedings of the Royal Society B. Science chatted with two of the study’s authors—Andrea Townsend, a behavioral ecologist at Hamilton College, and Dana Hawley, a biologist at the Virginia Polytechnic Institute and State University—about how self-isolating works throughout the animal kingdom. This interview has been edited for clarity and length. Get more great content like this delivered right to you! Q: How do animals know when they need to socially distance? Andrea Townsend: COVID-19 has so many symptoms that it’s hard to know when someone is sick. But some animals like house finches use very general behavioral cues, such as lethargy, to assess potential infections and avoid certain individuals. Dana Hawley: In other cases, animals have evolved fairly complex cues to induce social distancing. The Caribbean spiny lobster [a social lobster that normally lives in groups] has evolved to detect a chemical cue in the urine of sick lobsters and avoid areas that these sick lobsters occupy. Another example is in mandrills. Researchers took the feces of animals that did or did not have parasites and basically put a tiny amount on the side of a tree. They found that the primates were much more strongly drawn to the feces of unparasitized animals than those that were parasitized. © 2020 American Association for the Advancement of Science.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27420 - Posted: 08.15.2020

By Roni Caryn Rabin Neurologists around the world say that a small subset of patients with Covid-19 are developing serious impairments of the brain. Although fever, cough and difficulty breathing are the typical hallmarks of infection with the new coronavirus, some patients exhibit altered mental status, or encephalopathy, a catchall term for brain disease or dysfunction that can have many underlying causes, as well as other serious conditions. These neurological syndromes join other unusual symptoms, such as diminished sense of smell and taste as well as heart ailments. In early March, a 74-year-old man came to the emergency room in Boca Raton, Fla., with a cough and a fever, but an X-ray ruled out pneumonia and he was sent home. The next day, when his fever spiked, family members brought him back. He was short of breath, and could not tell doctors his name or explain what was wrong — he had lost the ability to speak. The patient, who had chronic lung disease and Parkinson’s, was flailing his arms and legs in jerky movements, and appeared to be having a seizure. Doctors suspected he had Covid-19, and were eventually proven right when he was finally tested. On Tuesday, doctors in Detroit reported another disturbing case involving a female airline worker in her late 50s with Covid-19. She was confused, and complained of a headache; she could tell the physicians her name but little else, and became less responsive over time. Brain scans showed abnormal swelling and inflammation in several regions, with smaller areas where some cells had died. Physicians diagnosed a dangerous condition called acute necrotizing encephalopathy, a rare complication of influenza and other viral infections. “The pattern of involvement, and the way that it rapidly progressed over days, is consistent with viral inflammation of the brain,” Dr. Elissa Fory, a neurologist with Henry Ford Health System, said through an email. “This may indicate the virus can invade the brain directly in rare circumstances.” The patient is in critical condition. © 2020 The New York Times Company

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: 27164 - Posted: 04.03.2020

Researchers at the National Institutes of Health found evidence that specific immune cells may play a key role in the devastating effects of cerebral malaria, a severe form of malaria that mainly affects young children. The results, published in the Journal of Clinical Investigation, suggest that drugs targeting T cells may be effective in treating the disease. The study was supported by the NIH Intramural Research Program. “This is the first study showing that T cells target blood vessels in brains of children with cerebral malaria,” said Dorian McGavern, Ph.D., chief of the Viral Immunology and Intravital Imaging Section at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) who co-directed the study with Susan Pierce, Ph.D., chief of the Laboratory of Immunogenetics at the National Institute of Allergy and Infectious Diseases (NIAID). “These findings build a bridge between mouse and human cerebral malaria studies by implicating T cells in the development of disease pathology in children. It is well established that T cells cause the brain vasculature injury associated with cerebral malaria in mice, but this was not known in humans.” More than 200 million people worldwide are infected annually with mosquito-borne parasites that cause malaria. In a subset of those patients, mainly young children, the parasites accumulate in brain blood vessels causing cerebral malaria, which leads to increased brain pressure from swelling. Even with available treatment, cerebral malaria still kills up to 25% of those affected resulting in nearly 400,000 deaths annually. Children who survive the infection will often have long-lasting neurological problems such as cognitive impairment.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27049 - Posted: 02.19.2020

Joshua Schrock You know what it’s like to be sick. You feel fatigued, maybe a little depressed, less hungry than usual, more easily nauseated and perhaps more sensitive to pain and cold. The fact that illness comes with a distinct set of psychological and behavioral features is not a new discovery. In medical terminology, the symptom of malaise encompasses some of the feelings that come with being ill. Animal behaviorists and neuroimmunologists use the term sickness behavior to describe the observable behavior changes that occur during illness. Health care providers often treat these symptoms as little more than annoying side effects of having an infectious disease. But as it turns out, these changes may actually be part of how you fight off infection. I’m an anthropologist interested in how illness and infection have shaped human evolution. My colleagues and I propose that all these aspects of being sick are features of an emotion that we call “lassitude.” And it’s an important part of how human beings work to recover from illness. The human immune system is a complex set of mechanisms that help you suppress and eliminate organisms – such as bacteria, viruses and parasitic worms – that cause infection. Activating the immune system, however, costs your body a lot of energy. This presents a series of problems that your brain and body must solve to fight against infection most effectively. Where will this extra energy come from? What should you do to avoid additional infections or injuries that would increase the immune system’s energy requirements even more? © 2010–2019, The Conversation US, Inc.

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: 26899 - Posted: 12.18.2019

By Matt Richtel Should you pick your nose? Don’t laugh. Scientifically, it’s an interesting question. Should your children pick their noses? Should your children eat dirt? Maybe: Your body needs to know what immune challenges lurk in the immediate environment. Should you use antibacterial soap or hand sanitizers? No. Are we taking too many antibiotics? Yes. “I tell people, when they drop food on the floor, please pick it up and eat it,” said Dr. Meg Lemon, a dermatologist in Denver who treats people with allergies and autoimmune disorders. Advertisement “Get rid of the antibacterial soap. Immunize! If a new vaccine comes out, run and get it. I immunized the living hell out of my children. And it’s O.K. if they eat dirt.” Dr. Lemon’s prescription for a better immune system doesn’t end there. “You should not only pick your nose, you should eat it,” she said. She’s referring, with a facetious touch, to the fact our immune system can become disrupted if it doesn’t have regular interactions with the natural world. “Our immune system needs a job,” Dr. Lemon said. “We evolved over millions of years to have our immune systems under constant assault. Now they don’t have anything to do.” She isn’t alone. Leading physicians and immunologists are reconsidering the antiseptic, at times hysterical, ways in which we interact with our environment. Sign up for Science Times We’ll bring you stories that capture the wonders of the human body, nature and the cosmos. Why? Let us turn to 19th-century London. The British Journal of Homeopathy, volume 29, published in 1872, included a startlingly prescient observation: “Hay fever is said to be an aristocratic disease, and there can be no doubt that, if it is not almost wholly confined to the upper classes of society, it is rarely, if ever, met with but among the educated.” Hay fever is a catchall term for seasonal allergies to pollen and other airborne irritants. With this idea that hay fever was an aristocratic disease, British scientists were on to something. © 2019 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: 26027 - Posted: 03.13.2019

Nicola Davis An overactive immune response appears to be a trigger for persistent fatigue, say researchers in a study that could shed light on the causes of chronic fatigue syndrome. Chronic fatigue syndrome (CFS) is a debilitating long-term condition in which individuals experience exhaustion that is not helped by rest, as well as pain, mental fogginess and trouble with memory and sleep. It is also known as myalgic encephalomyelitis (ME). Some studies into the condition have suggested the immune system could be involved, with viral infections one potential trigger for CFS. “The evidence is largely inconclusive – there are studies which have shown elevated levels of the inflammatory markers, but such abnormalities are quite inconsistent across studies,” said Alice Russell, first author of the research from King’s College London. Because it is not possible to predict who will get a virus, it is impossible to look at levels of biological molecules before, during and after a potential CFS “trigger” infection. Experts say they have used a group of people with a different condition as a model to explore how immune response might be linked to persistent fatigue. Writing in the journal Psychoneuroendocrinology, Russell and colleagues describe how they recruited 55 patients with a chronic hepatitis C infection. To treat the condition, all were given a six- to 12-month course of injections of interferon alpha, a protein that is produced naturally by the body and stimulates the white blood cells to provoke an immune response. The treatment has previously been linked to a side effect of ongoing fatigue in some patients. © 2018 Guardian News and Media Limited

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 25792 - Posted: 12.17.2018

Laura Sanders Skulls seem solid, but the thick bones are actually riddled with tiny tunnels. Microscopic channels cut through the skull bones of people and mice, scientists found. In mice, inflammatory immune cells use these previously hidden channels to travel from the bone marrow of the skull to the brain, the team reports August 27 in Nature Neuroscience. It’s not yet known whether immune cells travel these paths through people’s skulls. If so, these tunnels represent a newfound way for immune cells to reach — and possibly inflame — the brain. Along with other blood cells, immune cells are made in bones including those in the arm, leg, pelvis and skull. Researchers injected tracking dyes into bone marrow in the skull and other bones of mice, marking immune cells called neutrophils that originated in each locale. After a stroke, neutrophils flocked to the brain. Instead of coming equally from all sources of bone marrow, as some scientists had thought, most of these responding cells came from skull marrow, study coauthor Matthias Nahrendorf of Massachusetts General Hospital and Harvard Medical School and colleagues found. Curious about cells’ journeys from skull marrow to the brain, the researchers used powerful microscopes to look where skull meets brain. Tiny rivulets through the skull bone connected bone marrow inside the skull to the outer covering of the brain. In mice, neutrophils used these channels, which averaged about 22 micrometers across, as shortcuts to reach the brain. |© Society for Science & the Public 2000 - 2018

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: 25411 - Posted: 09.04.2018

Bone marrow, the spongy tissue inside most of our bones, produces red blood cells as well as immune cells that help fight off infections and heal injuries. According to a new study of mice and humans, tiny tunnels run from skull bone marrow to the lining of the brain and may provide a direct route for immune cells responding to injuries caused by stroke and other brain disorders. The study was funded in part by the National Institutes of Health and published in Nature Neuroscience. “We always thought that immune cells from our arms and legs traveled via blood to damaged brain tissue. These findings suggest that immune cells may instead be taking a shortcut to rapidly arrive at areas of inflammation,” said Francesca Bosetti, Ph.D., program director at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS), which provided funding for the study. “Inflammation plays a critical role in many brain disorders and it is possible that the newly described channels may be important in a number of conditions. The discovery of these channels opens up many new avenues of research.” Using state-of-the-art tools and cell-specific dyes in mice, Matthias Nahrendorf, M.D., Ph.D., professor at Harvard Medical School and Massachusetts General Hospital in Boston, and his colleagues were able to distinguish whether immune cells traveling to brain tissue damaged by stroke or meningitis, came from bone marrow in the skull or the tibia, a large legbone. In this study, the researchers focused on neutrophils, a particular type of immune cell, which are among the first to arrive at an injury site.

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: 25388 - Posted: 08.28.2018

By Esther Landhuis From savoring a piece of cake to hugging a friend, many of life’s pleasures trigger a similar reaction in the brain—a surge of chemicals that tell the body “that was good, do it again.” Research published Friday in Nature Communications suggests this feel-good circuit may do much more. Using lab tools to activate that reward circuit in mice, scientists discovered that its chemical signals reach the immune system, empowering a subset of bone marrow cells to slow the growth of tumors. The findings have yet to be confirmed in humans. But given the reward system is linked with positive emotions, the research offers a physiological mechanism for how a person’s psychological state could help to stall cancer progression. Plenty of research measures the health impact of stress and negative feelings, says Erica Sloan, a biologist at Monash University in Melbourne, Australia. But the potential for immune activity to shift in response to positive influences through the brain’s reward center—“that’s what I think is really exciting,” says Sloan, who studies neural-immune activity in cancer but was not involved in the present study. The notion that the brain talks to the immune system isn’t new. One of the most compelling examples is the placebo effect—the centuries-old observation that sugar pills can work as well as evidence-based medicine in some people. For years scientists have tried to unravel the biology behind this mysterious phenomenon. © 2018 Scientific American

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: 25205 - Posted: 07.14.2018