By Laurie McGinley An experimental Alzheimer’s drug designed to slow cognitive decline failed to meet the goals of two closely watched clinical trials, a discouraging development that underscores the challenges of developing treatments for the memory-robbing disease. Genentech, a division of health-care giant Roche, said in a news release Monday that the treatment, called gantenerumab, slowed the pace of decline in patients with early-stage disease but not enough to be statistically significant. The therapy was tested in identical late-stage trials, each with 1,000 participants. Half received placebos and half got the treatment. The studies lasted 27 months. The drug, a monoclonal antibody, is designed to remove from the brain clumps of an abnormal version of a protein called amyloid beta, a hallmark of the disease. The company said Monday that the treatment removed less amyloid beta than expected. Some scientists have thought for years that amyloid-busting medicines could slow the fatal neurodegenerative disease, but there have been multiple failures, and just a few encouraging signs, involving amyloid-busting drugs. “So many of our families have been directly affected by Alzheimer’s, so this news is very disappointing to deliver,” Levi Garraway, Roche’s chief medical officer and head of global product development, said in a statement. He said the company looks forward to sharing more information about the results “as we continue to search for new treatments for this complex disease.” Genentech said that 25 percent of the patients who received gantenerumab experienced a side effect that can cause brain swelling and bleeding but that most did not have symptoms and few needed to stop taking the drug. The company said it planned to present more data from the trials at an Alzheimer’s conference this month. The company assessed the drug by measuring trial participants’ performance on an 18-point measure of memory and cognition, called the Clinical Dementia Rating scale — Sum of Boxes. The news on gantenerumab is a disappointment for patients, physicians and researchers desperate for effective treatments for a disease that affects 6.5 million Americans.

Keyword: Alzheimers
Link ID: 28554 - Posted: 11.16.2022

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

Keyword: Neurotoxins; Alzheimers
Link ID: 28550 - Posted: 11.13.2022

by David Dobbs For 40 years, Leo Kanner and Hans Asperger have dominated virtually every story about the ‘pioneers of autism research.’ These two men published in 1943 and 1944, respectively, what were long accepted as the first descriptions of, as Kanner’s seminal paper claimed, ”children whose condition differs … markedly and uniquely from anything reported so far.” Both papers are absorbing, touching and authoritative. Both describe young people whose challenges defied the known diagnoses of the time but clearly fall into what we now call autism. And both offered a new diagnostic category for such people. Kanner’s 1943 paper, ”Autistic Disturbances of Affective Contact,” drew almost immediate attention. Within a year, he renamed the condition these children shared, dubbing it ‘early infantile autism,’ which soon became known as ‘autism’ or ‘Kanner’s syndrome.’ His articulation of the condition, based on observations of 11 children he and his associates treated in his Baltimore, Maryland, clinic, remained the standard well into the 1980s and involved three elements: Autism was a condition marked by: (1) emergence early in childhood, (2) deficits in communication and social interaction, and (3) restricted or repetitive behaviors and a desire for sameness. Even today, these three elements anchor the official diagnostic criteria in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, as well as the widely used International Classification of Diseases and Related Health Problems. Asperger’s 1944 paper, which presented case studies on four children he and his colleagues had seen in his clinic in Vienna, Austria, made its impact far more slowly. In fact, because Asperger published in German (and in a German journal in the middle of a war that had essentially halted transatlantic scholarly exchange), the paper went largely unnoticed outside Europe for decades. Asperger’s descriptions resembled Kanner’s in many ways, although he outlined a wider apparent range of intelligence and capabilities than Kanner did, with some of his study participants reaching prominence in their fields. Asperger coined the diagnostic term ‘autistic psychopathy.’ © 2022 Simons Foundation

Keyword: Autism
Link ID: 28544 - Posted: 11.09.2022

Jon Hamilton An idea that has propelled Alzheimer's research for more than 30 years is approaching its day of reckoning. Scientists are launching a study designed to make or break the hypothesis that Alzheimer's is caused by a sticky substance called beta-amyloid. The study will give an experimental anti-amyloid drug to people as young as 18 who have gene mutations that often cause Alzheimer's to appear in their 30s or 40s. The study comes after several experimental drugs have failed to prevent declines in memory and thinking even though they succeeded in removing amyloid from the brains of patients in the early stages of Alzheimer's. Those failures have eroded support for the idea that amyloid is responsible for a cascade of events that eventually lead to the death of brain cells. "Many of us think of that as the ultimate test of the amyloid hypothesis," says Dr. Randall Bateman, a professor of neurology at Washington University School of Medicine in St. Louis."If that doesn't work, nothing will work." The new experiment, called the DIAN-TU primary Prevention Trial, is scheduled to begin enrolling patients by the end of the year. The amyloid hypothesis can be traced to Dr. Alois Alzheimer, a pathologist who first described the disease that would bear his name in 1906. Alzheimer was working at a psychiatric clinic in Munich, where he had the chance to conduct an autopsy on a woman who died at 50 after experiencing memory loss, disorientation, and hallucinations. He observed that the woman's brain had an "unusual disease of the cerebral cortex," including "senile plaque" usually seen in much older people. © 2022 npr

Keyword: Alzheimers
Link ID: 28534 - Posted: 11.02.2022

By Erika Check Hayden Weeks after Valeria Schenkel took an experimental drug named after her, the daily seizures that had afflicted her from birth became less frequent. But the drug caused fluid to build up in her brain, and a year later, she died at age 3. The drug was given to only one other child, and she experienced the same side effect and nearly died last year. The drug contained snippets of genetic material tailor-made to turn off the mutated gene causing the extremely rare form of epilepsy that these children were born with. A handful of researchers and nonprofit organizations have raised millions of dollars to make these treatments, known as antisense drugs, for at least 19 children and adults with severe diseases that are too rare to garner interest from pharmaceutical companies. The treatments have helped some of these patients, raising hopes that the personalized approach might one day save thousands of lives. But the brain side effect, known as hydrocephalus, reported on Sunday at the American Neurological Association meeting in Chicago, is a blow for the niche medical field that has made rapid progress over the past five years. Hydrocephalus happens when too much fluid fills cavities in the brain, increasing pressure on brain tissue and risking lethal damage if untreated. “I think it’s worth saying: No question that encountering hydrocephalus has been a setback, sobering and important,” said Dr. Timothy Yu, the neurologist and genetics researcher at Boston Children’s Hospital who developed the drug, known as valeriasen. But traditional drug companies, he added, are not helping patients with thousands of rare, untreatable and rapidly progressing diseases that cause death and severe disabilities. Personalized genetic treatments may be their only hope. “We have to learn as much as we can from each and every one, because they’re just so incredibly valuable in every sense,” Dr. Yu said. Scientists first imagined creating “antisense oligonucleotide” drugs — pieces of custom-made DNA or RNA designed to correct for genetic errors in cells — in the 1960s. But it took decades to make stable and effective versions of such drugs. © 2022 The New York Times Company

Keyword: Epilepsy; Development of the Brain
Link ID: 28529 - Posted: 10.28.2022

Nina Lakhani The mystery behind the astronomical rise in neurological disorders like Parkinson’s disease and Alzheimer’s could be caused by exposure to environmental toxins that are omnipresent yet poorly understood, leading doctors warn. At a conference on Sunday, the country’s leading neurologists and neuroscientists will highlight recent research efforts to fill the gaping scientific hole in understanding of the role environmental toxins – air pollution, pesticides, microplastics, forever chemicals and more – play in increasingly common diseases like dementias and childhood developmental disorders. Humans may encounter a staggering 80,000 or more toxic chemicals as they work, play, sleep and learn – so many that it is almost impossible to determine their individual effects on a person, let alone how they may interact or the cumulative impacts on the nervous system over a lifespan. Some contact with environmental toxins is inevitable given the proliferation of plastics and chemical pollutants, as well as America’s hands off regulatory approach, but exposure is unequal. In the US, communities of color, Indigenous people and low income families are far more likely to be exposed to a myriad of pollutants through unsafe housing and water, manufacturing and agricultural jobs, and proximity to roads and polluting industrial plants, among other hazards. It’s likely genetic makeup plays a role in how susceptible people are to the pathological effects of different chemicals, but research has shown higher rates of cancers and respiratory disease in environmentally burdened communities. © 2022 Guardian News & Media Limited

Keyword: Alzheimers; Parkinsons
Link ID: 28526 - Posted: 10.26.2022

Andrew Gregory Health editor Scientists have discovered that it may be possible to spot signs of dementia as early as nine years before patients receive an official diagnosis. The findings raise the possibility that, in the future, at-risk people could be screened to help select those who could benefit from interventions, or help identify patients suitable for clinical trials for new treatments. Researchers at Cambridge University published the study – funded by the Medical Research Council with support from the NIHR Cambridge Biomedical Research Centre – in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. Dr Richard Oakley, associate director of research at the Alzheimer’s Society, said the “important” findings suggested that “for some people who go on to develop Alzheimer’s disease, memory and thinking problems can begin up to nine years before they receive a diagnosis”. Advertisement He added: “This opens up the possibility of screening programmes in the future to help identify people at risk and who may benefit from interventions, and identify more people suitable for clinical trials for new dementia treatments, which are both so desperately needed.” The study’s first author, Nol Swaddiwudhipong, said: “When we looked back at patients’ histories, it became clear that they were showing some cognitive impairment several years before their symptoms became obvious enough to prompt a diagnosis. The impairments were often subtle, but across a number of aspects of cognition. “This is a step towards us being able to screen people who are at greatest risk – for example, people over 50 or those who have high blood pressure or do not do enough exercise – and intervene at an earlier stage to help them reduce their risk.” Man in bed with pillow over his head. © 2022 Guardian News & Media Limited

Keyword: Alzheimers
Link ID: 28513 - Posted: 10.15.2022

Allison Whitten Our understanding of the inner workings of the human brain has long been held back by the practical and ethical difficulty of observing human neurons develop, connect and interact. Today, in a new study published in Nature, neuroscientists at Stanford University led by Sergiu Paşca report that they have found a new way to study human neurons — by transplanting human brainlike tissue into rats that are just days old, when their brains have not yet fully formed. The researchers show that human neurons and other brain cells can grow and integrate themselves into the rat’s brain, becoming part of the functional neural circuitry that processes sensations and controls aspects of behaviors. Using this technique, scientists should be able to create new living models for a wide range of neurodevelopmental disorders, including at least some forms of autism spectrum disorder. The models would be just as practical for neuroscientific lab studies as current animal models are but would be better stand-ins for human disorders because they would consist of real human cells in functional neural circuits. They could be ideal targets for modern neuroscience tools that are too invasive to use in real human brains. “This approach is a step forward for the field and offers a new way to understand disorders of neuronal functioning,” said Madeline Lancaster, a neuroscientist at the MRC Laboratory of Molecular Biology in Cambridge, U.K., who was not involved in the work. The work also marks an exciting new chapter in the use of neural organoids. Nearly 15 years ago, biologists discovered that human stem cells could self-organize and grow into small spheres that held different types of cells and resembled brain tissue. These organoids opened a new window into the activities of brain cells, but the view has its limits. While neurons in a dish can connect to each other and communicate electrically, they can’t form truly functional circuits or attain the full growth and computational prowess of healthy neurons in their natural habitat, the brain. Pioneering work by various research groups proved years ago that human brain organoids could be inserted into the brains of adult rats and survive. But the new study shows for the first time that the burgeoning brain of a newborn rat will accept human neurons and allow them to mature, while also integrating them into local circuits capable of driving the rat’s behavior. All Rights Reserved © 2022

Keyword: Development of the Brain
Link ID: 28512 - Posted: 10.13.2022

By Benjamin Mueller Svante Pääbo, a Swedish scientist who peered back into human history by retrieving genetic material from 40,000-year-old bones, producing a complete Neanderthal genome and launching the field of ancient DNA studies, was awarded the Nobel Prize in Physiology or Medicine on Monday. The prize recognized an improbable scientific career. Having once dreamed of becoming an Egyptologist, Dr. Pääbo devoted his early years of research to extracting genetic material from mummies, only for that research to run aground because the samples might have become contaminated by his and his colleagues’ own DNA. Within about two decades, in 2006, he had launched an unlikely effort to decipher a Neanderthal genome. He designed so-called clean rooms dedicated to handling ancient DNA, which protected his fossils from the genetic material of living humans. And dramatic advances in sequencing technology allowed him to decode the sort of badly damaged DNA found in ancient bones. “It was certainly considered to be impossible to recover DNA from 40,000-year-old bones,” said Dr. Nils-Göran Larsson, the chairman of the Nobel Committee for Physiology or Medicine and a professor of medical biochemistry at the Karolinska Institute in Stockholm. In 2010, Dr. Pääbo unveiled the Neanderthal genome. The publication opened a window into questions about what made early humans different from modern ones. It also helped scientists track genetic differences in modern humans and understand what role those differences play in disease, including Covid-19. In 2020, Dr. Pääbo and a colleague found that the coronavirus caused more severe symptoms in people who had inherited a stretch of Neanderthal DNA. Even some of Dr. Pääbo’s biggest admirers described the prize as unexpected. Analysts have long speculated that the scientists who sequenced the modern human genome were strong contenders for a Nobel Prize, not thinking that the scientist who sequenced Neanderthal DNA would get there first. But geneticists said that the two projects were interwoven: Rapid advances in sequencing technology that followed the beginning of the Human Genome Project in 1990, they said, helped Dr. Pääbo to interpret tiny quantities of Neanderthal DNA, damaged as they were from tens of thousands of years underground. © 2022 The New York Times Company

Keyword: Evolution; Genes & Behavior
Link ID: 28500 - Posted: 10.05.2022

McKenzie Prillaman Some researchers are celebrating this week’s announcement that a drug candidate for Alzheimer’s disease slowed the rate of cognitive decline for people in a clinical trial by 27%. Others, however, remain hesitant, wanting to see data beyond what was disclosed in a 27 September press release. If the results stand up, the treatment — called lecanemab — would be the first of its kind to show a strong signal of cognitive benefit in a robust trial. “It’s such a win for our field,” says Liana Apostolova, a neurologist at the Indiana University School of Medicine in Indianapolis. The results are “quite promising”, says Caleb Alexander, an internal-medicine specialist and epidemiologist at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, and an advisory committee member for the US Food and Drug Administration (FDA). But, he adds, “we’ll have to see what the full analysis of the trial suggests”. Alexander and others also note that, although the results indicate that lecanemab does provide some clinical benefit, the degree to which it does so is small. Developed by Eisai, a pharmaceutical company in Tokyo, and biotechnology firm Biogen in Cambridge, Massachusetts, lecanemab is a monoclonal antibody designed to clear clumps of protein from the brain that many think are a root cause of Alzheimer’s disease. This theory, known as the ‘amyloid hypothesis’, holds that the protein amyloid-β accumulates into toxic deposits as the disease progresses, ultimately causing dementia. Whether or not lecanemab confirms the amyloid hypothesis remains to be seen, researchers say. “I don’t think one study will prove a very long-standing controversial hypothesis,” says Brent Forester, director of the Geriatric Psychiatry Research Program at McLean Hospital in Belmont, Massachusetts, who helped to run the clinical trial for lecanemab. “But one positive study supports the hypothesis.” Amyloid is “associated with the problem, but it isn’t ‘the’ problem”, says George Perry, a neurobiologist at the University of Texas at San Antonio and a sceptic of the amyloid hypothesis. “If you modulate it, of course you can have some small benefit.” © 2022 Springer Nature Limited

Keyword: Alzheimers
Link ID: 28497 - Posted: 10.01.2022

By Deborah Balthazar It’s a frustration many parents know all too well: You’ve finally lulled your crying baby to sleep, so you put them down in their crib … and the wailing begins again. Science may have a trick for you. Carrying a crying infant for about five minutes, then sitting for at least another five to eight minutes can calm and lull the baby to sleep long enough to allow a parent to put the child down without waking them, researchers report September 13 in Current Biology. Some of those same researchers previously showed that carrying a crying baby soothes the child and calms a racing heart rate (SN: 4/18/13). For the new study, the team looked at what it takes to get that crying baby to nod off and stay asleep. The researchers put heart rate monitors on 21 crying babies, ranging in age from newborns to 7 months old. The team also took videos of the infants, monitoring their moods as their mothers carried them around a room, sat holding them and laid them in a crib. That allowed the team to observe how the babies responded to different environments, whether they were crying, fussy, alert or drowsy, heartbeat by heartbeat. “We tested the physiology behind these things that tend to be kind of common knowledge, though it’s not really well understood why they work,” says Gianluca Esposito, a developmental psychologist at the University of Trento in Italy. The babies’ heart rates slowed and they stopped crying when their mothers picked them up and carried them around for five minutes. Some infants even fell asleep. But the researchers also noticed that the babies tended to respond to the movement of the parent, whether they were in deep sleep or not. For instance, a baby’s heart rate quickened if a parent turned quickly while walking or tried to put the baby down. © Society for Science & the Public 2000–2022.

Keyword: Sleep; Development of the Brain
Link ID: 28494 - Posted: 10.01.2022

Nicola Davis Science correspondent If the taste of kale makes you screw up your face, you are not alone: researchers have observed foetuses pull a crying expression when exposed to the greens in the womb. While previous studies have suggested our food preferences may begin before birth and can be influenced by the mother’s diet, the team says the new research is the first to look directly at the response of unborn babies to different flavours. “[Previously researchers] just looked at what happens after birth in terms of what do [offspring] prefer, but actually seeing facial expressions of the foetus when they are getting hit by the bitter or by the non-bitter taste, that is something which is completely new,” said Prof Nadja Reissland, from Durham University, co-author of the research. Writing in the journal Psychological Science, the team noted that aromas from the mother’s diet were present in the amniotic fluid. Taste buds can detect taste-related chemicals from 14 weeks’ gestation, and odour molecules can be sensed from 24 weeks’ gestation. To delve into whether foetuses differentiate specific flavours, the team looked at ultrasound scans from almost 70 pregnant women, aged 18 to 40 from the north-east of England, who were split into two groups. One group was asked to take a capsule of powdered kale 20 minutes before an ultrasound scan, and the other was asked to take a capsule of powdered carrot. Vegetable consumption by the mothers did not differ between the kale and carrot group. The team also examined scans from 30 women, taken from an archive, who were not given any capsules. All the women were asked to refrain from eating anything else in the hour before their scans. The team then carried out a frame-by-frame analysis of the frequency of a host of different facial movements of the foetuses, including combinations that resembled laughing or crying. Overall, the researchers examined 180 scans from 99 foetuses, scanned at either 32 weeks, 36 weeks, or at both time points. © 2022 Guardian News & Media Limited

Keyword: Development of the Brain; Chemical Senses (Smell & Taste)
Link ID: 28493 - Posted: 09.28.2022

Terriline Porelle is puzzling over two mysteries. The first is: what’s plaguing her? For the past two years, the formerly healthy, active, 34-year-old resident of Cocagne, N.B. has been experiencing many strange and alarming symptoms, including muscle twitches and blurred vision, auditory hallucinations, brain fog and loss of balance and co-ordination. The second mystery is why health authorities no longer seem interested in finding out why she’s ill. “It’s like nobody’s really looking to see what’s going on and it doesn’t make any sense,” she said. Ms. Porelle is one of 48 people who were initially identified between late 2020 and May, 2021, as being part of a cluster of patients in New Brunswick who all had a mysterious brain illness, which the province referred to as a “potential neurological syndrome of unknown cause.” Doctors and researchers puzzled over the cases for months. Then, in a February report, the province announced that there was no mystery illness, and that its investigation into the matter had concluded. An independent oversight committee had found that the 48 patients were likely suffering from various previously known diseases that had simply been misdiagnosed, the report said. But some of the patients and their families say their suffering remains very real – and that it’s made worse by the fact that they’re no closer to getting answers about what’s causing it. The province’s report said neurologists on the oversight committee had provided potential alternative diagnoses for 41 of the 48 patients, including Alzheimer’s disease and other types of dementia, post-concussion syndrome, chronic severe anxiety disorder and cancer. It recommended that patients contact their primary caregivers for referrals to further treatment, or that they seek help from a specialized clinic in Moncton called the Moncton Interdisciplinary Neurodegenerative Diseases (MIND) Clinic.

Keyword: Alzheimers
Link ID: 28491 - Posted: 09.28.2022

by Angie Voyles Askham / Brain connectivity patterns in people with autism and other neuropsychiatric conditions are more closely related to genetics than to phenotypic traits, according to two new studies. The findings highlight why a single brain biomarker for autism has remained elusive, the researchers say. The condition’s genetic heterogeneity has hampered the search for a shared brain signature: More than 100 genes have been identified as strongly linked to autism, and multiple copy number variations (CNVs) — deleted or duplicated stretches of genetic code — can increase a person’s likelihood of the condition. Autism also often overlaps with other conditions, such as schizophrenia and attention-deficit/hyperactivity disorder (ADHD), making autism-specific markers difficult to disentangle. Common variants tied to autism overlap strongly with those linked to schizophrenia and high IQ, for example, whereas rare autism-linked variants track with low IQ. According to the new papers, however, autism’s genetic heterogeneity corresponds to similarly disparate maps of ‘functional connectivity’ — a measure of which brain areas activate in sync while the brain is at rest. “What we’re seeing is that these groups of variants have specific functional connectivity signatures,” says lead investigator Sébastien Jacquemont, associate professor of pediatrics at the University of Montreal in Canada. The findings need to be replicated, says Aaron Alexander-Bloch, assistant professor of psychiatry at the University of Pennsylvania and the Children’s Hospital of Philadelphia, who was not involved in the work, but they point to the importance of subgrouping study participants based on their underlying genetics. © 2022 Simons Foundation

Keyword: Autism; Brain imaging
Link ID: 28490 - Posted: 09.28.2022

by Charles Q. Choi Infection during pregnancy may be associated with having an autistic child simply because mothers of autistic children are prone to infections, a new study finds. The results suggest that “common infections during pregnancy do not seem increase their children’s risk of autism,” says study investigator Martin Brynge, a psychiatrist and doctoral student of global public health at the Karolinska Institutet in Stockholm, Sweden. “Prevention of maternal infections would likely not affect the prevalence of autism in the population.” A great deal of previous research has linked maternal infection during pregnancy with autism and intellectual disability in children. Whether the former causes the latter, however, has remained uncertain. For instance, both autism and intellectual disability are linked with gene variants that may influence the immune system, so mothers of children with either condition may also just be more vulnerable to serious infections. The new study analyzed data from 549,967 children, including 267,995 girls, living in Stockholm County who were born between 1987 and 2010; about 34,000 of the children had been exposed to a maternal infection requiring specialized health care, according to data from Sweden’s National Patient Register and National Medical Birth Register. Of the exposed children, 3.3 percent have autism, compared with 2.5 percent of unexposed children — a 16 percent increase in the chance of autism. But maternal infection in the year before pregnancy was also linked with a 25 percent greater chance of autism. “Mothers who had an infection during pregnancy may not be comparable to those mothers without infections,” Brynge says. “There may be systematic differences at the group level.” © 2022 Simons Foundation

Keyword: Autism; Neuroimmunology
Link ID: 28488 - Posted: 09.24.2022

By Mark Johnson A study using the electronic health records of more than 6 million Americans over age 65 found those who had covid-19 ran a greater risk of receiving a new diagnosis of Alzheimer’s disease within a year. The study, led by researchers at Case Western Reserve University School of Medicine and published in the Journal of Alzheimer’s Disease, does not show that covid-19 causes Alzheimer’s, but adds to a growing body of work suggesting links between the two. The results suggest researchers should be tracking older patients who recover from covid to see if they go on to show signs of memory loss, declining brain function or Alzheimer’s disease. The study found that for every 1,000 seniors with covid-19, seven will be diagnosed with Alzheimer’s within a year, slightly above the five-in-a-thousand diagnosis rate for seniors who did not have covid. “We know that covid can affect the brain, but I don’t think anyone had looked at new diagnoses of Alzheimer’s,” said Pamela Davis, one of the study’s co-authors and a research professor at Case Western Reserve University School of Medicine. Colleague Rong Xu said she had expected to see some increase among seniors sickened by covid, but was surprised “by the extent of the increase and how rapidly it occurred.” The study, though “important and useful” was “limited,” said Gabriel de Erausquin, director of the Laboratory of Brain Development, Modulation and Repair at University of Texas Health San Antonio, who was not involved in the research. He cautioned that a diagnosis of Alzheimer’s disease is not necessarily confirmation of the disease. Doctors sometimes diagnose Alzheimer’s based on changes in behavior, or responses to a memory test. These are considered less accurate than imaging or spinal fluid tests that measure two types of proteins, beta-amyloid and phosphorylated tau, which accumulate abnormally in the brains of people with Alzheimer’s. Brain scans that look for structural changes, such as the shrinking of certain regions, are another more accurate indicator. © 1996-2022 The Washington Post

Keyword: Alzheimers
Link ID: 28479 - Posted: 09.17.2022

by Nora Bradford A well-studied brain response to sound, called the M100, appears earlier in life in autistic children than in their non-autistic peers, according to a new longitudinal study. The finding suggests that the auditory cortex in children with autism matures unusually quickly, a growth pattern seen previously in other brain regions. “It’s a demonstration that when we look for autism markers in the brain, they can be very age-specific,” says lead investigator J. Christopher Edgar, associate professor of radiology at the Children’s Hospital of Philadelphia in Pennsylvania. For that reason, longitudinal studies such as this one — in which Edgar and his colleagues assessed children at up to three different ages — are essential, he adds. “If the two populations being studied have different rates of brain maturation, then the pattern of findings changes across time.” At the time of the first magnetoencephalography (MEG) scan, when the children were 6 to 9 years old, those with autism were more likely to have an M100 response to a barely audible tone in the right hemisphere than non-autistic children were. But this difference disappeared in the next two visits, presumably because the M100 response typically appears during early adolescence. By contrast, the M50 response, which occurs throughout life, beginning in utero, showed no significant difference between the two groups at any visit. The team also evaluated ‘phase locking,’ a measure of how similar a participant’s neural activity is from scan to scan within a certain frequency band. Autistic participants demonstrated more mature phase-locking patterns at the first visit, which then diminished at the later two visits. © 2022 Simons Foundation

Keyword: Autism; Hearing
Link ID: 28478 - Posted: 09.17.2022

Sara Reardon More than 500,000 years ago, the ancestors of Neanderthals and modern humans were migrating around the world when a pivotal genetic mutation caused some of their brains to improve suddenly. This mutation, researchers report in Science1, drastically increased the number of brain cells in the hominins that preceded modern humans, probably giving them a cognitive advantage over their Neanderthal cousins. “This is a surprisingly important gene,” says Arnold Kriegstein, a neurologist at the University of California, San Francisco. However, he expects that it will turn out to be one of many genetic tweaks that gave humans an evolutionary advantage over other hominins. “I think it sheds a whole new light on human evolution.” When researchers first reported the sequence of a complete Neanderthal genome in 20142, they identified 96 amino acids — the building blocks that make up proteins — that differ between Neanderthals and modern humans, as well as some other genetic tweaks. Scientists have been studying this list to learn which of these changes helped modern humans to outcompete Neanderthals and other hominins. Cognitive advantage To neuroscientists Anneline Pinson and Wieland Huttner at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany, one gene stood out. TKTL1 encodes a protein that is made when a fetus’s brain is first developing. A mutation in the human version changed one amino acid, resulting in a protein that is different from those found in hominin ancestors, Neanderthals and non-human primates. The researchers suspected that this protein could increase the proliferation of neural progenitor cells, which become neurons, as the brain develops, specifically in an area called the neocortex — a region involved in cognitive function. This, they reasoned, could contribute to modern humans’ cognitive advantage. © 2022 Springer Nature Limited

Keyword: Evolution; Genes & Behavior
Link ID: 28477 - Posted: 09.14.2022

Jon Hamilton In some families, Alzheimer's disease seems inevitable. "Your grandmother has it, your mom has it, your uncle has it, your aunts have it, your cousin has it. I always assumed that I would have it," says Karen Douthitt, 57. "It was always in our peripheral vision," says Karen's sister June Ward, 61. "Our own mother started having symptoms at age 62, so it has been a part of our life." Nearly a decade ago, Karen, June, and an older sister, Susie Gilliam, 64, set out to learn why Alzheimer's was affecting so many family members. Since then, each sister has found out whether she carries a rare gene mutation that makes Alzheimer's inescapable. And all three have found ways to help scientists trying to develop treatments for the disease. I met Karen and June in 2015, at the first-ever conference for families with a particular type of genetic mutation in which Alzheimer's often appears in middle age. The annual conference is sponsored by the Alzheimer's Association and the Dominantly Inherited Alzheimer's Network Trials Unit, a research program run by Washington University School of Medicine in St. Louis. Karen and June had come to Washington, D.C., for the family conference because of something they had just learned about a cousin on their mother's side. The cousin had developed Alzheimer's in her 50s. And genetic tests showed that she carried a rare, inherited gene mutation called presenilin 1. It's one of three mutations that typically cause Alzheimer's to appear in middle age. The three gene mutations responsible for early Alzheimer's are unlike a better known gene called APOE4, which merely increases the likelihood somewhat that a person will develop Alzheimer's – and usually at age 65 or older. In contrast, the early-onset mutations, including presenilin 1, make it almost certain an individual will develop the disease, and usually before age 60. Each child of a parent who has the presenilin 1 mutation has a 50% chance of inheriting it. © 2022 npr

Keyword: Alzheimers; Genes & Behavior
Link ID: 28474 - Posted: 09.14.2022

ByRodrigo Pérez Ortega We humans are proud of our big brains, which are responsible for our ability to plan ahead, communicate, and create. Inside our skulls, we pack, on average, 86 billion neurons—up to three times more than those of our primate cousins. For years, researchers have tried to figure out how we manage to develop so many brain cells. Now, they’ve come a step closer: A new study shows a single amino acid change in a metabolic gene helps our brains develop more neurons than other mammals—and more than our extinct cousins, the Neanderthals. The finding “is really a breakthrough,” says Brigitte Malgrange, a developmental neurobiologist at the University of Liège who was not involved in the study. “A single amino acid change is really, really important and gives rise to incredible consequences regarding the brain.” What makes our brain human has been the interest of neurobiologist Wieland Huttner at the Max Planck Institute of Molecular Cell Biology and Genetics for years. In 2016, his team found that a mutation in the ARHGAP11B gene, found in humans, Neanderthals, and Denisovans but not other primates, caused more production of cells that develop into neurons. Although our brains are roughly the same size as those of Neanderthals, our brain shapes differ and we created complex technologies they never developed. So, Huttner and his team set out to find genetic differences between Neanderthals and modern humans, especially in cells that give rise to neurons of the neocortex. This region behind the forehead is the largest and most recently evolved part of our brain, where major cognitive processes happen. The team focused on TKTL1, a gene that in modern humans has a single amino acid change—from lysine to arginine—from the version in Neanderthals and other mammals. By analyzing previously published data, researchers found that TKTL1 was mainly expressed in progenitor cells called basal radial glia, which give rise to most of the cortical neurons during development. © 2022 American Association for the Advancement of Science.

Keyword: Development of the Brain; Evolution
Link ID: 28472 - Posted: 09.10.2022