Links for Keyword: Neurotoxins
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By Kristen French Combat in nature is often a matter of tooth and claw, fang and talon. But some creatures have devised devious and dramatic ways to weaponize their bodily fluids, expelling them in powerful streams for the purposes of attack or self-defense. Researcher Elio Challita became fascinated by fluid ejections in nature when he began studying an insect called the sharpshooter, which pees one droplet at a time using a method called superpropulsion. These insects consume 300 times their own body weight per day in xylem sap, a watery solution of minerals and other nutrients found in the roots, stems, and leaves of plants. To efficiently expel the resulting waste, they use a kind of internal catapult that helps overcome the surface tension in the droplets. Challita and a team of researchers from the Bhamla Lab at Georgia Tech decided to survey the biomechanics and fluid dynamics that govern fluid ejections across the animal kingdom to see what commonalities they could find. Among others, they identified a number of creatures that use bodily fluids as powerful weapons in the fight for survival. These fluid ejections defy gravity and rebel against traditional notions of predator-prey tactics. The team’s review, “Fluid Ejections in Nature,” is forthcoming in the Annual Review of Chemical and Biological Engineering. 1. Ringnecked Spitting Cobra Cobras of the Naja genus defend against threats by spitting venom with extreme precision toward the eyes of an enemy, up to 6.5 feet away. These snakes release the venom through hollow microscopic fangs and can adjust the distribution of their spit with rapid movements. Spitting cobras have a venom discharge orifice that is more circular in shape than non-spitting species, which gives the venom more forward force. Contraction in the venom gland also helps. A 90-degree bend near the lip of the orifice gives the snake more precise control over venom flow. Naja pallida cobras can spit venom at average speeds of 1.27 milliliters per second. © 2024 NautilusNext Inc.,
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain
Link ID: 29278 - Posted: 04.30.2024
By Frances Vinall More than two-thirds of young children in Chicago could be exposed to lead-contaminated water, according to an estimate by the Johns Hopkins Bloomberg School of Public Health and the Stanford University School of Medicine. The research, published Monday in the journal JAMA Pediatrics, estimated that 68 percent of children under the age of 6 in Chicago are exposed to lead-contaminated drinking water. Of that group, 19 percent primarily use unfiltered tap water, which was associated with a greater increase in blood lead levels. “The extent of lead contamination of tap water in Chicago is disheartening — it’s not something we should be seeing in 2024,” lead author Benjamin Huynh, assistant professor of environmental health and engineering at the Johns Hopkins Bloomberg School of Public Health, said in a news release. The study suggested that residential blocks with predominantly Black and Hispanic populations were less likely to be tested for lead, but also disproportionately exposed to contaminated water. Gina Ramirez, Midwest regional lead of environmental health for the Natural Resources Defense Council, said she grew up in Chicago drinking bottled water, but now uses filtered water for her own family, because of a generational awareness of “not trusting my tap” to be safe. The study “confirmed my worst fears that children living in vulnerable populations in the city are the most impacted,” she said. “All children deserve to grow up in a healthy city, and to learn that something inside their home is impacting so many kids health and development is a huge wake-up call.”
Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 4: Development of the Brain
Link ID: 29207 - Posted: 03.23.2024
By Lisa Sanders, M.D. Surrounded by the detritus of a Thanksgiving dinner, the woman was loading the dishwasher when a loud thump thundered through the house. She hurried out of the kitchen to find her husband of 37 years sitting on the second-floor landing. Her son and son-in-law, an emergency-room doctor, crouched at his side. Her husband protested that he was fine, then began to scooch himself on his bottom into the bedroom. The two young men helped him to his feet. The man’s body shook with a wild tremor that nearly knocked him down again. “I was getting into bed and fell,” he explained — though the bed was too far away to make this at all likely. “Get some sleep,” the woman said gently once her husband was settled in the bed. “We’ll go to the hospital in the morning.” Her daughter and son-in-law had arrived that morning and already mentioned the change they noticed in the 70-year-old senior. The normally gregarious man was oddly quiet. And the tremor he had for as long as they could remember was much more prominent. His hands shook so much he had trouble using his fork and ended up eating much of his Thanksgiving dinner with his fingers. And now this fall, this confusion — they were worried. His wife was also worried. Just after Halloween, she traveled for business, and when she came back, her husband was much quieter than usual. Even more concerning: When he spoke, he didn’t always make sense. “Have you had a stroke?” she asked her first day home. He was fine, he insisted. But a few days later she came home from work to find his face covered with cuts. He was shaving, he said, but his hand shook so much that he kept cutting himself. “There is something wrong with me,” he acknowledged. It was Thanksgiving week, but she was able to get him an appointment at his doctor’s office the next day. They were seen by the physician assistant (P.A.). She was kind, careful and thorough. After hearing of his confusion, she asked the man what day it was. “Friday?” he offered uncertainly. It was Wednesday. Could he touch his finger to his nose and then to her finger, held an arm’s length away? He could not. His index finger carved jagged teeth in the air as he sought his own nose then stretched to touch her finger. And when she asked him to stand, his entire body wobbled dangerously. “It’s all happened so quickly,” the man’s wife said. The P.A. reviewed his lab tests. They were all normal. She then ordered an M.R.I. of the brain. That, she explained, should give them a better idea of what direction to take. But, she added, if he falls or seems © 2024 The New York Times Company
Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 4: Development of the Brain
Link ID: 29182 - Posted: 03.07.2024
By Geoffrey Giller From the brightly colored poison frogs of South America to the prehistoric-looking newts of the Western US, the world is filled with beautiful, deadly amphibians. Just a few milligrams of the newt’s tetrodotoxin can be fatal, and some of those frogs make the most potent poisons found in nature. In recent years, scientists have become increasingly interested in studying poisonous amphibians and are starting to unravel the mysteries they hold. How is it, for example, that the animals don’t poison themselves along with their would-be predators? And how exactly do the ones that ingest toxins in order to make themselves poisonous move those toxins from their stomachs to their skin? Even the source of the poison is sometimes unclear. While some amphibians get their toxins from their diet, and many poisonous organisms get theirs from symbiotic bacteria living on their skin, still others may or may not make the toxins themselves — which has led scientists to rethink some classic hypotheses. Over the long arc of evolution, animals have often turned to poisons as a means of defense. Unlike venoms — which are injected via fang, stinger, barb, or some other specialized structure for offensive or defensive purposes — poisons are generally defensive toxins a creature makes that must be ingested or absorbed before they take effect. Amphibians tend to store their poisons in or on their skin, presumably to increase the likelihood that a potential predator is deterred or incapacitated before it can eat or grievously wound them. Many of their most powerful toxins — like tetrodotoxin, epibatidine and the bufotoxins originally found in toads — are poisons that interfere with proteins in cells, or mimic key signaling molecules, thus disrupting normal function. © 2023 Annual Reviews
Related chapters from BN: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 4: Development of the Brain
Link ID: 28757 - Posted: 04.29.2023
Linda Geddes Science correspondent Lead exposure during childhood may lead to reduced cognitive abilities in later life, meaning people experience symptoms of dementia sooner, data suggest. The study, one of the first to investigate the decades-long consequences of lead poisoning, suggests countries could face an explosion of people seeking support for dementia as individuals who were exposed to high lead levels during early life progress into old age. “In the US, and I would imagine the UK, the prime years when children were exposed to the most lead was in the 1960s and 70s. That’s when the most leaded gasoline was getting used, lead paint was still common, and municipal water systems hadn’t done much to clean up their lead,” said Prof John Robert Warren at the University of Minnesota in Minneapolis, who was involved in the research. “Those children who are now in their 40s, 50s and early 60s, will soon be entering the time of life when cognitive impairment and dementia are really common. So there’s this coming wave, potentially, of problems for the people who were most exposed.” Although scientists have long known that children and adults who are exposed to lead have poorer cognitive and educational outcomes, few studies have investigated the longer-term consequences. Warren and his colleagues combined data from the US-based longitudinal Health and Retirement Study (HRS), which has followed the brain health of thousands of adults over several decades, with census records to pinpoint where 1,089 of these individuals lived as children. They also mapped the locations of towns and cities that used lead pipes and had acidic or alkaline water – a proxy for high lead exposure. The research, published in Science Advances, revealed that people who lived in cities with lead-contaminated water as children had worse baseline cognitive functioning – a measure of their ability to learn, process information, and reason – at age 72, compared with those who did not. The difference was equivalent to being roughly eight years older. © 2022 Guardian News & Media Limited
Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 4: Development of the Brain
Link ID: 28550 - Posted: 11.13.2022
By Katherine J. Wu For a rodent that resembles the love child of a skunk and a steel wool brush, the African crested rat carries itself with a surprising amount of swagger. The rats “very much have the personality of something that knows it’s poisonous,” says Sara Weinstein, a biologist at the University of Utah and the Smithsonian Conservation Biology Institute who studies them. In sharp contrast to most of their skittish rodent kin, Lophiomys imhausi lumber about with the languidness of porcupines. When cornered, they fluff up the fur along their backs into a tip-frosted mohawk, revealing rows of black-and-white bands that run like racing stripes down their flanks — and, at their center, a thicket of specialized brown hairs with a honeycomb-like texture. Those spongy hairs contain a poison powerful enough to bring an elephant to its knees, and are central to Dr. Weinstein’s recent research, which confirmed ideas about how this rat makes itself so deadly. Give them a chance and African crested rats will take nibbles from the branch of a poison arrow tree. It’s not for nutrition. Instead, they will chew chunks of the plants and spit them back out into their fur, anointing themselves with a form of chemical armor that most likely protects them from predators like hyenas and wild dogs. The ritual transforms the rats into the world’s only known toxic rodents, and ranks them among the few mammals that borrow poisons from plants. Dr. Weinstein’s research, which was published last week in the Journal of Mammalogy, is not the first to document the crested rats’ bizarre behavior. But the new paper adds weight to an idea described nearly a decade ago, and offers an early glimpse into the animals’ social lives. First documented in the scientific literature in 1867, the rarely-glimpsed African crested rat “has captured so much interest for so long,” said Kwasi Wrensford, a behavioral ecologist at the University of California, Berkeley who wasn’t involved in the study. “We’re now just starting to unpack what makes this animal tick.” © 2020 The New York Times Company
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 0: ; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 27592 - Posted: 11.27.2020
By Lisa Friedman and Coral Davenport WASHINGTON — The Trump administration on Thursday finalized a decision not to impose any limits on perchlorate, a toxic chemical compound found in rocket fuel that contaminates water and has been linked to fetal and infant brain damage. The move by the Environmental Protection Agency was widely expected, after The New York Times reported last month that Andrew Wheeler, the E.P.A. administrator, had decided to effectively defy a court order that required the agency to establish a safe drinking-water standard for the chemical by the end of June. In addition to not regulating, the E.P.A. overturned the underlying scientific finding that declared perchlorate a serious health risk for five million to 16 million people in the United States. The E.P.A. said California and Massachusetts and other states had already taken regulatory steps to reduce the contamination. “Today’s decision is built on science and local success stories and fulfills President Trump’s promise to pare back burdensome ‘one-size-fits-all’ overregulation for the American people,” Mr. Wheeler said in a statement. “State and local water systems are effectively and efficiently managing levels of perchlorate. Our state partners deserve credit for their leadership on protecting public health in their communities, not unnecessary federal intervention.” Environmentalists said both moves showed a disregard for science, the law and public health, and they criticized the agency for claiming credit for state regulations done in the face of federal inaction. “Today’s decision is illegal, unscientific and unconscionable,” said Erik D. Olson, the senior strategic director for health at the Natural Resources Defense Council, an advocacy group. “The Environmental Protection Agency is threatening the health of pregnant moms and young children with toxic chemicals in their drinking water at levels that literally can cause loss of I.Q. points. Is this what the Environmental Protection Agency has come to?” © 2020 The New York Times Company
Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 27308 - Posted: 06.19.2020
By Joshua Sokol The city of Minamata, Japan, is dotted with monuments commemorating victims of an industrial mass poisoning decades ago. High in the hills, a small stone memorial honors other deaths—of cats sacrificed in secret to science. Now, after restudying the remains of one of those cats, a team of scientists is arguing, controversially, that the long-standing explanation for the tragedy is wrong. No one questions the root cause of the disaster, which at minimum poisoned more than 2000 people: mercury in a chemical factory’s wastewater that was dumped into Minamata Bay and taken up by seafood eaten by fishermen and their families. At first, the chemical form of the mercury, which ultimately killed many of its victims and left many babies with severe neurological disorders, was unknown. But in 1968, the Japanese government blamed methylmercury, a common byproduct of mercury pollution. Many studies supported that conclusion, finding methylmercury spikes in shellfish, bay sludge, and even hundreds of umbilical cords from babies delivered during the time. But methylmercury is not the culprit, says Ingrid Pickering, an x-ray spectroscopist at the University of Saskatchewan. “Our work is indicating that it’s something else”: an unusual mercury compound that may say little about the broader threat of mercury pollution. Minamata has long been a vivid case study of mercury’s dangers. The metal is toxic on its own, but it becomes far more dangerous when bacteria in natural environments convert it into methylmercury, an organic compound, readily absorbed by living tissues, that can be concentrated and passed up food chains. Since the 1990s, scientists have argued that the Chisso chemical factory in Minamata produced methylmercury and dumped it directly into the bay. © 2020 American Association for the Advancement of Science.
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 27140 - Posted: 03.25.2020
Davide Castelvecchi The group of nerve agents known as Novichoks are to be added to the Chemical Weapons Convention’s list of controlled substances, in one of the first major changes to the treaty since it was agreed in the 1990s. The compounds, developed by the Soviet Union during the cold war, came to prominence after they were used in a high-profile assassination attempt on a former Russian military officer, Sergei Skripal, in Salisbury, UK, in March last year. The Organisation for the Prohibition of Chemical Weapons (OPCW), which is tasked with enforcing the treaty, announced the decision to explicitly ban Novichoks on 27 November as representatives from the 193 member states met in The Hague this week for a periodic review of the convention. The member states agreed unanimously to classify Novichoks as chemical weapons, the OPCW said. The update to the treaty, which will come into effect in 180 days, was initially proposed by the United States, Canada and the Netherlands. “There is a recognition that we all win with this agreement,” says Alastair Hay, an environmental toxicologist at the University of Leeds, UK, who was at the meeting. “The decision means that OPCW can now keep tabs on these chemicals.” The OPCW has the power to send inspectors to any signatory country to search for evidence of production of banned chemicals. It also can send experts to help countries to investigate crime scenes where chemical agents may have been used. © 2019 Springer Nature Limited
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 26863 - Posted: 12.02.2019
By Nicholas Bakalar Long-term exposure to air pollution is associated with lower scores on tests of mental acuity, researchers have found. And one reason may be that air pollution causes changes in brain structure that resemble those of Alzheimer’s disease. The scientists studied 998 women ages 73 to 87 and free of dementia, periodically giving them tests of learning and memory. They used magnetic resonance imaging to detect brain atrophy, or wasting, and then scored the deterioration on its degree of similarity to the brain atrophy characteristic of Alzheimer’s disease. They matched Environmental Protection Agency data on air pollution to the women’s residential addresses. Over 11 years of follow-up, they found that the greater the women’s exposure to PM 2.5, the tiny particulate matter that easily penetrates the lungs and bloodstream, the lower their scores on the cognitive tests. After excluding cases of dementia and stroke, they also found a possible reason for the declining scores: The M.R.I. results showed that increased exposure to PM 2.5 was associated with increased brain atrophy, even before clinical symptoms of dementia had appeared. The study is in the journal Brain. “PM 2.5 alters brain structure, which then accelerates memory decline,” said the lead author, Diana Younan, a postdoctoral researcher at the University of California. “I just want people to be aware that air pollution can affect their health, and possibly their brains.” © 2019 The New York Times Company
Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain
Link ID: 26849 - Posted: 11.26.2019
Catherine Offord When Lilian Calderón-Garcidueñas discovered abundant hallmarks of Alzheimer’s disease in a batch of human brain samples a few years ago, she initially wasn’t sure what to make of it. The University of Montana neuropathologist had been studying the brains as part of her research on environmental effects on neural development, and this particular set of samples came from autopsy examinations carried out on people who had died suddenly in Mexico City, where she used to work as a researcher and physician. Although Calderón-Garcidueñas had collected much of the tissue herself while attending the autopsies in Mexico, the light-microscope slides she was analyzing had been prepared by her colleagues, so she was in the dark about what patient each sample came from. By the end of the project, she’d identified accumulations of the Alzheimer’s disease–associated proteins amyloid-ß and hyperphosphorylated tau in almost all of the 203 brains she studied. “When I started opening envelopes to see who [each sample] belonged to . . . I was devastated,” she says. The people whose brains she’d been studying were not only adults, but teens and even children. The youngest was 11 months old. “My first thought was, ‘What am I going to do with this? What am I going to tell people?’” she says. “I was not expecting such a devastating, extreme pathology.” Despite her shock, Calderón-Garcidueñas had a reason to be on the lookout for signs of a disease usually associated with the elderly in these samples. For the last three decades, she’d been studying the health effects of Mexico City’s notoriously polluted air—a blight that earned the capital the dubious distinction of most polluted megacity on the planet from the United Nations in 1992. During that time, she’s discovered many links between exposure to air pollution and signs of neural damage in animals and humans. Although her findings are observational, and the pathology of proteins such as amyloid-ß is not fully understood, Calderón-Garcidueñas argues that air pollution is the most likely culprit behind the development of the abnormalities she saw in her postmortem samples—plus many other detrimental changes to the brains of Mexico City’s residents. © 1986–2019 The Scientist
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 4: Development of the Brain
Link ID: 26665 - Posted: 10.02.2019
The mysterious ailments experienced by some 40 Canadian and U.S. diplomats and their families while stationed in Cuba may have had nothing to do with sonic "attacks" identified in earlier studies. According to a new Canadian study, obtained exclusively by Radio-Canada's investigative TV program Enquête, the cause could instead be neurotoxic agents used in pesticide fumigation. A number of Canadians and Americans living in Havana fell victim to an unexplained illness starting in late 2016, complaining of concussion-like symptoms, including headaches, dizziness, nausea and difficulty concentrating. Some described hearing a buzzing or high-pitched sounds before falling sick. In the wake of the health problems experienced over the past three years, Global Affairs Canada commissioned a clinical study by a team of multidisciplinary researchers in Halifax, affiliated with the Brain Repair Centre, Dalhousie University and the Nova Scotia Health Authority. "The working hypothesis actually came only after we had most of the results," Dr. Alon Friedman, the study's lead author, said in an interview. The researchers identified a damaged region of the brain that is responsible for memory, concentration and sleep-and-wake cycle, among other things, and then looked at how this region could come to be injured. "There are very specific types of toxins that affect these kinds of nervous systems ... and these are insecticides, pesticides, organophosphates — specific neurotoxins," said Friedman. "So that's why we generated the hypothesis that we then went to test in other ways." Twenty-six individuals participated in the study, including a control group of people who never lived in Havana. ©2019 CBC/Radio-Canada
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 14: Attention and Higher Cognition
Link ID: 26627 - Posted: 09.20.2019
By Maanvi Singh The world’s most widely used insecticides may delay the migrations of songbirds and hurt their chances of mating. In the first experiment to track the effects of a neonicotinoid on birds in the wild, scientists captured 24 white-crowned sparrows as they migrated north from Mexico and the southern United States to Canada and Alaska. The team fed half of those birds with a low dose of the commonly used agricultural insecticide imidacloprid and the other half with a slightly higher dose. An additional 12 birds were captured and dosed with sunflower oil, but no pesticide. Within hours, the dosed birds began to lose weight and ate less food, researchers report in the Sept. 13 Science. Birds given the higher amount of imidacloprid (3.9 milligrams per kilogram of body mass) lost 6 percent of their body mass within six hours. That’s about 1.6 grams for an average bird weighing 27 grams. Tracking the birds (Zonotrichia leucophrys) revealed that the pesticide-treated sparrows also lagged behind the others when continuing their migration to their summer mating grounds. The findings suggest that neonicotinoid insecticides, already implicated in dropping bee populations, could also have a hand in the decline of songbird populations across North America. From 1966 to 2013, the populations of nearly three-quarters of farmland bird species across the continent have precipitously dropped. The researchers dosed the birds in the lab with carefully measured amounts of pesticide mixed with sunflower oil. In the wild, birds might feed on seeds coated with imidacloprid. The highest dose that “we gave each bird is the equivalent of if they ate one-tenth of [a single] pesticide-coated corn seed,” says Christy Morrissey, a biologist at the University of Saskatchewan in Saskatoon, Canada. “Frankly, these were minuscule doses we gave the birds.” © Society for Science & the Public 2000–2019.
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 26608 - Posted: 09.13.2019
Tina Hesman Saey ORLANDO — Being exposed to a chemical early in life can be a bit like a choose-your-own-adventure book: Some things that happen early on may hurt you later, but only if you make certain choices, an unpublished study in mice suggests. Mouse pups were exposed to the chemical bisphenol A (BPA) for only five days after birth, a crucial time during which mice’s livers develop. BPA, once common in plastics, has been linked to a host of health problems in people, from diabetes to heart disease (SN: 10/11/08, p. 14). But depending on diet as adults, the mice either grew up to be healthy or to have enlarged livers and high cholesterol. As long as the BPA-exposed mice ate mouse chow for the rest of their lives, the rodents remained healthy, molecular biologist Cheryl Walker of Baylor College of Medicine in Houston reported April 7 at the 2019 Experimental Biology meeting. But researchers switched some BPA-exposed mice to a high-fat diet as adults. Those mice had larger livers, higher cholesterol and more metabolic problems than mice who ate a high-fat diet but were not exposed to BPA as pups, Walker said. BPA exposure immediately altered epigenetic marks at more than 5,400 genes, including 3,000 involved in aging. Epigenetic marks are chemical tags on DNA or on histones — protein around which DNA winds in a cell — that don’t change information in genes themselves, but affect gene activity. |© Society for Science & the Public 2000 - 2019
Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 26134 - Posted: 04.13.2019
By Jennifer Couzin-Frankel For the millions of people treated for cancer, “chemo brain” can be an unnerving and disabling side effect. It causes memory lapses, trouble concentrating, and an all-around mental fog, which appear linked to the treatment and not the disease. Although the cognitive effects often fade after chemotherapy ends, for some people the fog persists for years, even decades. And doctors and researchers have long wondered why. Now, a new study suggests an answer in the case of one chemotherapy drug: Brain cells called microglia may orchestrate chemo brain by disrupting other cells that help maintain the brain’s communication system. “I can’t tell you how many patients I see who look at me when I explain [chemo brain] and say, ‘I’ve been living with this for 10 years and thought I was crazy,’” says Michelle Monje, a pediatric neuro-oncologist and neuroscientist at Stanford University in Palo Alto, California. It’s still mostly a mystery how common long-term cognitive impairment is after chemo. In one recent study by clinical neuropsychologist Sanne Schagen at the Netherlands Cancer Institute in Amsterdam, it affected 16% of breast cancer survivors 6 months after treatment. Monje began to probe the cognitive effects of cancer treatment in the early 2000s, starting with radiation, a therapy that can be far more debilitating than chemotherapy. A Science paper she and her colleagues published in 2003 suggested radiation affected a type of brain cell called microglia, which protect the brain against inflammation. Just like immune cells in the blood, microglia—which make up at least 10% of all brain cells—become activated during injury or infection. © 2018 American Association for the Advancement of Science
Related chapters from BN: Chapter 17: Learning and Memory; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 25759 - Posted: 12.07.2018
By Donald G. McNeil Jr. The first treatment for sleeping sickness that relies on pills alone was approved on Friday by Europe’s drug regulatory agency, paving the way for use in Africa, the last bastion of the horrific disease. With treatment radically simplified, sleeping sickness could become a candidate for elimination, experts said, because there are usually fewer than 2,000 cases in the world each year. The disease, also called human African trypanosomiasis, is transmitted by tsetse flies. The protozoan parasites, injected as the flies suck blood, burrow into the brain. Before they kill, drive their victims mad in ways that resemble the last stages of rabies. The personalities of the infected change. They have terrifying hallucinations and fly into rages; they have been known to beat their children and even attack family members with machetes. They may become ravenous and scream with pain if water touches their skin. Only in the end, do they lapse into a long coma and die. The new drug, fexinidazole, cures all stages of the disease within 10 days. Previously, everyone with the parasites found in a blood test also had to undergo a spinal tap to see if the parasites had reached their brains. If so, patients had to suffer through a complex and sometimes dangerous intravenous regimen requiring hospitalization. An oral treatment that can safely be taken at home “is a completely new paradigm — it could let us bring treatment down to the village level,” said Dr. Bernard Pecoul, founder and executive director of the Drugs for Neglected Diseases Initiative, which was started in 2005 by the medical charity Doctors Without Borders to find new cures for tropical diseases. © 2018 The New York Times Company
Related chapters from BN: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 12: Psychopathology: The Biology of Behavioral Disorders
Link ID: 25695 - Posted: 11.17.2018
By Eric Schlosser In April 1906, a Republican president of the United States met privately with a notorious socialist at the White House. The president was Theodore Roosevelt; the socialist was Upton Sinclair; and the two set aside their political differences to discuss an issue of great mutual concern: food safety. A few months earlier, Sinclair’s novel “The Jungle” had created public outrage about the sanitary conditions at America’s slaughterhouses. Roosevelt had distrusted the meatpacking industry for years, angered by the putrid meat sold to the Army and served to his troops during the Spanish-American War. In 1906 the United States was the only major industrialized nation without strict laws forbidding the sale of contaminated and adulterated food. In their absence, the free market made it profitable to supply a wide range of unappetizing fare. Ground-up insects were sold as brown sugar. Children’s candy was routinely colored with lead and other heavy metals. Beef hearts and other organ meats were processed, canned and labeled as chicken. Perhaps one-third of the butter for sale wasn’t really butter but rather all sorts of other things — beef tallow, pork fat, the ground-up stomachs of cows and sheep — transformed into a yellowish substance that looked like butter. Historians have long credited the unlikely alliance of Roosevelt and Sinclair for passage of the Meat Inspection Act and the Pure Food and Drug Act of 1906. In “The Poison Squad,” Deborah Blum makes a convincing case that a now forgotten chemist at the Department of Agriculture, Harvey Washington Wiley, played a more important role — not only in ensuring the passage of those bills but also in changing popular attitudes toward government intervention on behalf of consumers. The origins of today’s food safety laws, drug safety laws, labeling requirements and environmental regulations can be found in the arguments of the Progressive movement at the turn of the last century. As the Trump administration proudly weakens or eliminates those measures, the life work of a 19th-century U.S.D.A. chemist has an unfortunate significance. © 2018 The New York Times Company
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 25582 - Posted: 10.17.2018
By Mike Ives HONG KONG — A large study in China suggests a link between air pollution and negative effects on people’s language and math skills. The link between pollution and respiratory diseases is well known, and most experts now believe that small particulates may also raise the risk for strokes and heart attacks. Whether this form of air pollution impairs cognition is not yet certain, but several studies have hinted at a connection. The latest study, by researchers based in China and the United States, analyzed how long-term exposure to air pollution affected performance on nationwide math and word-recognition tests by more than 25,000 people across 162 Chinese counties. It was published on Monday in Proceedings of the National Academy of Sciences. The authors based their findings on models they built that combined weather and pollution data from specific locations in China where people had taken nationwide tests in 2010 and 2014, as well as the test scores themselves. Their analysis tried to document how short- and long-term pollution exposure might have affected the scores — and, by extension, the test-takers’ brains. The authors found that the cognitive impact of cumulative exposure among the test takers was especially pronounced among older men, and that the results were troubling in part because cognitive decline and impairment are risk factors for Alzheimer’s disease and other forms of dementia. The study “further amplifies the need to tackle air pollution now to protect the health of particularly the young and elderly populations,” Heather Adair-Rohani, a technical officer for public health and environment at the World Health Organization in Geneva, which was not involved in the study, said in an email. © 2018 The New York Times Company
Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 4: Development of the Brain
Link ID: 25393 - Posted: 08.29.2018
By Melissa Healy At some point in their treatment for cancer, somewhere between 17% and 75% of patients with malignancies that don’t affect the central nervous system report the sensation that a mental fog has set in. For months or years after their hair has grown back, the exhaustion has lifted and the medical appointments taper off, the “new normal” for these patients includes problems with concentration, word-finding, short-term memory and multitasking. Their doctors nod their heads knowingly: It’s “chemobrain,” they report. Among the nation’s roughly 15.5 million cancer survivors, the ranks of those who’ve experienced mental fog after cancer treatment are probably increasing as detection and therapies improve, survival rates rise and lives are extended. But when it comes to cancer’s cognitive aftermath, the medical profession’s expertise ends. Why chemobrain happens, how long it will linger, and what deficits it actually causes — and especially whether it could be treated, or even prevented — are questions for which oncologists have no answers. But they want them. And three specialists from the National Cancer Institute have issued an appeal to neuroscientists for help. “We need an infusion of new ideas," said Todd S. Horowitz, a cognitive psychologist and program director in the institute’s Division of Cancer Control and Population Sciences. “Cognitive neuroscience would help us characterize the deficits people have and allow us to connect them to particular brain systems." Writing this week in the journal Trends in Neurosciences, Horowitz and two fellow researchers at the institute drafted a road map toward a better understanding of the condition officially known as cancer-related cognitive impairment, which was first described by breast cancer survivors.
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 14: Attention and Higher Cognition
Link ID: 25089 - Posted: 06.14.2018
Geoff Brumfiel Sergei Skripal and his daughter, Yulia, were found slumped on a bench in the city of Salisbury on March 4. Experts quickly assessed that Skripal — a former Russian intelligence official accused of spying for the British — had been poisoned with a nerve agent. On Monday, British Prime Minister Theresa May named the agent in a speech before Parliament. "It is now clear that Mr. Skripal and his daughter were poisoned with a military-grade nerve agent of a type developed by Russia," she said. "This is part of a group of nerve agents known as Novichok." Novichok agents are extremely rare. "As far as I know, I don't know anybody who knows how to make it except these guys in Russia," says Dan Kaszeta, a chemical weapons expert with Strongpoint Security in London. "They've been a deep, dark secret." Novichok means "newcomer" in Russian. Kaszeta says that Novichok agents were developed in the 1980s as a new weapon in the waning days of the Cold War. Novichok chemicals were designed to evade equipment carried by NATO troops. "They wanted to develop nerve agents that the West couldn't detect," he says. According to a defector's report published by the Stimson Center in 1995, they were developed at the State Scientific Research Institute of Organic Chemistry and Technology in Moscow. As the U.S. and Russia were laying the groundwork to dismantle their chemical weapons stockpiles, researchers at the institute were working in secret to develop the new Novichok chemicals. © 2018 npr
Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 24747 - Posted: 03.13.2018