Katharine Sanderson A large, UK-based study of genetics and autism spectrum disorder (ASD) has been suspended, following criticism that it failed to properly consult the autism community about the goals of the research. Concerns about the study include fears that its data could potentially be misused by other researchers seeking to ‘cure’ or eradicate ASD. The Spectrum 10K study is led by Simon Baron-Cohen, director of the Autism Research Centre (ARC) at the University of Cambridge, UK. The £3-million (US$4-million) project, which is funded by the London-based biomedical funding charity Wellcome, is the largest genetic study of ASD in the United Kingdom. It aims to collect DNA samples, together with information on participants’ mental and physical health, from 10,000 people with autism and their families. This will be used to study the genetic and environmental contributions to ASD, and to co-occurring conditions such as epilepsy and gut-health problems. “If we can understand why these co-occurring conditions are more frequent in autistic people, that could open the door to treatment or management of very distressing symptoms,” says Baron-Cohen. But soon after the study’s high-profile launch on 24 August, people with autism and some ASD researchers expressed concern that it had gone ahead without meaningfully consulting the autism community. Fears about the sharing of genetic data and an alleged failure to properly explain the benefits of the research have been raised by a group called Boycott Spectrum 10K, which is led by people with autism. The group plans to protest outside the ARC premises in Cambridge in October. A separate petition against the study gathered more than 5,000 signatures. © 2021 Springer Nature Limited

Keyword: Autism; Genes & Behavior
Link ID: 28012 - Posted: 09.29.2021

by Giorgia Guglielmi About five years ago, when his younger twin brothers reached their thirties, Giacomo Vivanti started to wonder how the pair, who both have autism, would fare in middle and old age. In particular, he wondered if they might be prone to develop age-related neurological conditions. His brothers didn’t show any signs of ill health or cognitive deterioration, but Vivanti, associate professor of early detection and intervention at the A.J. Drexel Autism Institute in Philadelphia, Pennsylvania, knew that the scientific literature provided few clear answers. “I was pretty shocked to learn that we have such limited knowledge of outcomes as children with autism become adults, and as they age,” Vivanti says. It prompted him to scour four years’ worth of data from Medicaid, the largest healthcare program in the United States, to determine the incidence of neurodegenerative conditions among 30- to 64-year-olds with autism. That group, he and his colleagues reported last month, is about 2.5 times as likely to be diagnosed with early-onset Alzheimer’s or other forms of dementia as the general population. The study is one of a handful that have found higher-than-average rates of neurodegenerative conditions in autistic adults. The risk estimates for Parkinson’s disease in autistic people range from 15 to 20 percent, compared with about 1 percent in the general population. Similarly, the prevalence of dementia is less than 1 percent in non-autistic people but about 4 percent in those with autism. None of these studies offer solid evidence, but their results are strong enough to warrant further investigation, researchers say. © 2021 Simons Foundation

Keyword: Autism; Alzheimers
Link ID: 28011 - Posted: 09.29.2021

James Cusack Being autistic, for me and the 700,000 other autistic people in the UK, often means spending a lot of time inhabiting a world that doesn’t work well for you. This is why it’s vital that the needs and preferences of autistic people are better understood. A trial of a therapy whose findings were published this week attempts to address this issue by trying to ensure the needs of toddlers who may be autistic are recognised. On one hand, the results are exciting, but they are also complex. Complexity is always hard to communicate. The international research study, led by Prof Andrew Whitehouse at the University of Western Australia in Perth, is technically well designed. It partly replicates a previous trial, and has promising results. Of its two main findings, one is exciting for child development. The second is thornier in how it relates to autism diagnoses. Advertisement The therapy used in the trial was an adapted version of one used among children who are not autistic. It focuses on working with parents to understand how a child prefers to play, and supports them to adapt their own behaviour to match their toddler’s natural way of interacting. Play is one of the fundamental building blocks of how children begin to learn how to interact with people and the world around them. From speaking to autistic people and families, we know that developing communication and language skills alongside finding ways to ensure families feel able to support autistic people are top priorities for autism research. Social communication skills make a huge difference in all our lives. They improve our chances of being able to explain our needs, build stronger relationships and find employment: all things that autistic people can find challenging. © 2021 Guardian News & Media Limited

Keyword: Autism
Link ID: 28010 - Posted: 09.29.2021

By Tara Ellison As menopause hit, I found I wasn’t as interested in intimacy as I used to be. Sex started to feel like a box that needed to be checked a couple of times a week, and that was causing problems in my marriage. But it wasn’t just sex. I felt was slowing down in many areas. After hot flashes in my 40s had sent me running to the gynecologist for help, I’d been using bioidentical creams to balance my declining hormones. When, at 51, I confided to a friend that I’d had limited success with what my doctor prescribed, she said that she was thriving on something called hormonal “pellets.” I grilled her about them and then made an appointment with her practitioner, an internal medicine doctor. He ordered extensive lab work, which showed that my testosterone levels were very low, which can happen with aging. The doctor said I had two options: do nothing, which he said would eventually likely lead to loss of muscle, decreased bone density and a host of other health complications. Or up my testosterone. Testosterone therapy for women is a hotly debated subject. Studies suggest that testosterone can heighten libido in women with hypoactive sexual desire disorder (HSDD), at least in the short term. A recent statement by a group of international medical societies involved with women’s health endorsed the use of testosterone therapy in women for HSDD, and specifically excluded pellets and injectables as “not recommended.” It also cautioned there was not enough data to support the use of testosterone therapy for cognitive performance.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 28009 - Posted: 09.29.2021

By Jonathan Lambert Identical siblings are used to sharing a lot with their twin, including their DNA. But new research suggests all identical twins share a common signature of twinhood, not in their DNA, but on it. This signature is part of the epigenome, chemical markers that dot many spots along DNA and influence the activity of genes without altering their sequence. Identical twins everywhere largely share a specific set of these marks that persists from birth to adulthood, researchers report September 28 in Nature Communications. These shared epigenetic tags could be used to identify people who were conceived as identical twins but lost their sibling in the womb or were separated at birth. “This paper is absolutely fascinating,” says Nancy Segal, a developmental psychologist at California State University, Fullerton who has researched twins but wasn’t involved in the study. The research sets the groundwork for scientists to better understand “what might cause a fertilized egg to split and form monozygotic [identical] twins,” she says. Despite humans’ age-old fascination with identical twins, the biological process that generates them, known as monozygotic twinning, “is an enigma,” says Jenny van Dongen, an epigeneticist at Vrije Universiteit Amsterdam. Researchers know that identical twins form after a fertilized egg, called a zygote, somehow splits into two embryos during development. But why this cleavage happens remains unknown, van Dongen says. For the most part, identical twins don’t run in families, and they occur at roughly the same rate worldwide — about 3 to 4 per 1,000 births. With no clear genetic or environmental cause, the prevailing hypothesis is that identical twins arise at random, she says. © Society for Science & the Public 2000–2021.

Keyword: Genes & Behavior; Epigenetics
Link ID: 28008 - Posted: 09.29.2021

By Judith Graham The approval of a controversial new drug for Alzheimer’s disease, Aduhelm, is shining a spotlight on mild cognitive impairment (MCI) — problems with memory, attention, language or other cognitive tasks that exceed changes expected with normal aging. After initially indicating that Aduhelm could be prescribed to anyone with dementia, the Food and Drug Administration now specifies that the prescription drug be given to individuals with MCI or early-stage Alzheimer’s, the groups in which the medication was studied. Yet this narrower recommendation raises questions. What does a diagnosis of MCI mean? Is Aduhelm appropriate for all people with MCI, or only some? And who should decide which patients qualify for treatment: dementia specialists or primary care physicians? Debate surrounds Aduhelm because its effectiveness has not been proved, its cost is high (an estimated $56,000 a year, not including expenses for imaging and monthly infusions), and its potential side effects are significant (41 percent of patients in the drug’s clinical trials experienced brain swelling and bleeding). Furthermore, an FDA advisory committee strongly recommended against Aduhelm’s approval, and Congress is investigating the process leading to the FDA’s decision. Medicare is studying whether it should cover the medication, and Veterans Affairs has declined to do so under most circumstances. Clinical trials for Aduhelm, developed by Biogen, based in Cambridge, Mass., excluded adults over 85, people taking blood thinners, people who had experienced a stroke, and those with cardiovascular disease or impaired kidney or liver function, among other conditions. If those criteria were broadly applied, 85 percent of people with MCI would not qualify for the drug, according to a research letter in the Journal of the American Medical Association.

Keyword: Alzheimers
Link ID: 28007 - Posted: 09.29.2021

By Carl Zimmer Ancient human footprints preserved in the ground across the White Sands National Park in New Mexico are astonishingly old, scientists reported on Thursday, dating back about 23,000 years to the Ice Age. The results, if they hold up to scrutiny, would rejuvenate the scientific debate about how humans first spread across the Americas, implying that they did so at a time when massive glaciers covered much of their path. Researchers who have argued for such an early arrival hailed the new study as firm proof. “I think this is probably the biggest discovery about the peopling of America in a hundred years,” said Ciprian Ardelean, an archaeologist at Autonomous University of Zacatecas in Mexico who was not involved in the work. “I don’t know what gods they prayed to, but this is a dream find.” For decades, many archaeologists have maintained that humans spread across North and South America only at the end of the last ice age. They pointed to the oldest known tools, including spear tips, scrapers and needles, dating back about 13,000 years. The technology was known as Clovis, named for the town of Clovis, N.M., where some of these first instruments came to light. The age of the Clovis tools lined up neatly with the retreat of the glaciers. That alignment bolstered a scenario in which Siberian hunter-gatherers moved into Alaska during the Ice Age, where they lived for generations until ice-free corridors opened and allowed them to expand southward. But starting in the 1970s, some archaeologists began publishing older evidence of humanity’s presence in North America. Last year, Dr. Ardelean and his colleagues published a report of stone tools in a mountain cave in Mexico dating back 26,000 years. © 2021 The New York Times Company

Keyword: Evolution
Link ID: 28006 - Posted: 09.25.2021

By Jonathan Lambert Vampire bats may be bloodthirsty, but that doesn’t mean they can’t share a drink with friends. Fights can erupt among bats over gushing wounds bit into unsuspecting animals. But bats that have bonded while roosting often team up to drink blood away from home, researchers report September 23 in PLOS Biology. Vampire bats (Desmodus rotundus) can form long-term social bonds with each other through grooming, sharing regurgitated blood meals and generally hanging out together at the roost (SN: 10/31/19). But whether these friendships, which occur between both kin and nonkin, extend to the bats’ nightly hunting had been unclear. “They’re flying around out there, but we didn’t know if they were still interacting with each other,” says Gerald Carter, an evolutionary biologist at Ohio State University in Columbus. To find out, Carter and his colleague Simon Ripperger of the Museum für Naturkunde in Berlin, built on previous research that uncovered a colony’s social network using bat backpacks. Tiny computer sensors glued to 50 female bats in Tolé, Panama, continuously registered proximity to other sensors both within the roost and outside, revealing when bats met up while foraging. Two common vampire bats feed on a cow near La Chorrera, Panama. It can take 10 to 40 minutes for a bat to bite a small, diamond-shaped wound into an animal’s flesh, and fights can sometimes break out over access to wounds. But researchers found that bats who are friendly back at the roost likely feed together in the field, potentially saving time and energy. © Society for Science & the Public 2000–2021

Keyword: Evolution
Link ID: 28005 - Posted: 09.25.2021

By Kimberly Hickok Seahorses are some of the most dazzling fish in the sea. They’re also the only group of animals in which the males, not the females, go through pregnancy and give birth. Now, new research finds the male’s brood pouch—which can hold up to 1000 baby seahorses at a time—develops and functions like a human placenta. “Evolution is just mind boggling,” says Camilla Whittington, an evolutionary biologist at the University of Sydney who led the new work. The study is the first to thoroughly examine how males nurture their young brood while they’re still in the pouch, says Mari Kawaguchi, an evolutionary biologist at Sophia University in Tokyo. Kawaguchi, who has studied seahorses for some 2 decades, has long suspected pregnant seahorses develop something resembling a placenta. Now, at last, there’s proof. Male seahorses start their path toward fatherhood with a dance. They twirl together with their chosen female under the water, changing colors and linking tails as they pirouette around a shared holdfast. Next, they align the female’s ovipositor with the male’s pouch opening so the female can deposit her eggs. Once the deed is done, the male gently sways to settle the eggs. Ten days to 6 weeks later, depending on the species, the male spends hours in labor, pumping and thrusting to force hundreds of tiny babies out into the water. There, they drift until they are grown. As for dad, he is ready for another round of courtship within hours after birth. But during pregnancy, males have one goal: Provide the embryos with everything they need, from oxygen to nutrients to antibodies. “One of the biggest challenges that all pregnant parents have is getting oxygen to their embryos and carbon dioxide away from the embryos,” Whittington says. “That’s really what motivated our study–how do those baby seahorses actually breathe, if you will, inside the brood pouch?” © 2021 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 28004 - Posted: 09.25.2021

by Chloe Williams In June 2020, cannabidiol hit what has become a familiar hurdle in fragile X research: Like many previous drug candidates, it missed its primary target in clinical testing. Among 109 young people with fragile X syndrome who took the drug and 101 who took a placebo, researchers saw no meaningful difference in a rating of social avoidance. A secondary analysis factored into the trial’s original design offered a glimmer of hope, though. A subset of 91 participants showed marked improvement on the same measure after treatment with the drug, according to unpublished findings. Among that group, the gene underlying fragile X syndrome, called FMR1, is awash with methyl groups, which block its expression of the protein FMRP. By contrast, the remaining participants have only partially methylated copies of the gene and may make more FMRP. “Looking at methylation was pretty important to find that subgroup that had the most optimal response,” says Randi Hagerman, medical director of the MIND Institute at the University of California, Davis, who led one of the trial sites. The subgroup’s improvements meet only the minimum threshold for one measure of statistical significance — they have a p-value of 0.02 — and the results await replication, something the company running the trials, Zynerba Pharmaceuticals, is working on. But the trial’s design reflects a fundamental shift in how researchers are trying to advance drug development for fragile X syndrome, one of the leading inherited causes of intellectual disability and autism. © 2021 Simons Foundation

Keyword: Development of the Brain; Genes & Behavior
Link ID: 28003 - Posted: 09.25.2021

Jon Hamilton People who have had a stroke appear to regain more hand and arm function if intensive rehabilitation starts two to three months after the injury to their brain. A study of 72 stroke patients suggests this is a "critical period," when the brain has the greatest capacity to rewire, a team reports in this week's journal PNAS. The finding challenges the current practice of beginning rehabilitation as soon as possible after a stroke and suggests intensive rehabilitation should go on longer than most insurance coverage allows, says Elissa Newport, a co-author of the study and director of the Center for Brain Plasticity and Recovery at Georgetown University Medical Center. Newport was speaking in place of the study's lead author, Dr. Alexander Dromerick, who died after the study was accepted but before it was published. If the results are confirmed with other larger studies, "the clinical protocol for the timing of stroke rehabilitation would be changed," says Li-Ru Zhao, a professor of neurosurgery at Upstate Medical University in Syracuse, N.Y., who was not involved in the research. The study involved patients treated at Medstar National Rehabilitation Hospital in Washington, D.C., most in their 50s and 60s. One of the study participants was Anthony McEachern, who was 45 when he had a stroke in 2017. Just a few hours earlier, McEachern had been imitating Michael Jackson dance moves with his kids. But at home that night he found himself unable stand up. © 2021 npr

Keyword: Stroke; Learning & Memory
Link ID: 28002 - Posted: 09.22.2021

By Carl Zimmer Sign up for Science Times Get stories that capture the wonders of nature, the cosmos and the human body. Get it sent to your inbox. For half a billion years or so, our ancestors sprouted tails. As fish, they used their tails to swim through the Cambrian seas. Much later, when they evolved into primates, their tails helped them stay balanced as they raced from branch to branch through Eocene jungles. But then, roughly 25 million years ago, the tails disappeared. Charles Darwin first recognized this change in our ancient anatomy. But how and why it happened has remained a mystery. Now a team of scientists in New York say they have pinpointed the genetic mutation that may have erased our tails. When the scientists made this genetic tweak in mice, the animals didn’t grow tails, according to a new study that was posted online last week. This dramatic anatomical change had a profound impact on our evolution. Our ancestors’ tail muscles evolved into a hammock-like mesh across the pelvis. When the ancestors of humans stood up and walked on two legs a few million years ago, that muscular hammock was ready to support the weight of upright organs. Although it’s impossible to definitively prove that this mutation lopped off our ancestors’ tails, “it’s as close to a smoking gun as one could hope for,” said Cedric Feschotte, a geneticist at Cornell who was not involved in the study. Darwin shocked his Victorian audiences by claiming that we descended from primates with tails. He noted that while humans and apes lack a visible tail, they share a tiny set of vertebrae that extend beyond the pelvis — a structure known as the coccyx. “I cannot doubt that it is a rudimentary tail,” he wrote. © 2021 The New York Times Company

Keyword: Evolution; Genes & Behavior
Link ID: 28001 - Posted: 09.22.2021

By Leigh Weingus I’ve struggled with sleep since I was a teenager, and have spent almost as long trying to fix it. I’ve absorbed countless books and articles on getting better sleep that instructed me to go blue-light free at least two hours before bedtime, take nightly baths to lower my body temperature, keep my phone far from my bedroom and avoid caffeine after 12 p.m. In between all my diligent sleep hygiene work, I couldn’t help but feel like there was a larger force at play. My sleep seemed to change throughout my menstrual cycle, for example, getting worse in the days before my period and significantly better afterward. When I was pregnant, I experienced the best sleep of my life, and when I stopped breastfeeding, I didn’t sleep for days. I finally started to ask myself: When we talk about getting better sleep, why aren’t we talking more about hormones? According to the National Sleep Foundation, the lifetime risk of insomnia is 40 percent higher for women than it is for men. Blaming this discrepancy entirely on hormones oversimplifies it — women also tend to take on the bulk of household worrying and emotional labor, and they tend to experience higher levels of anxiety. But according to Mary Jane Minkin, an obstetrician-gynecologist and clinical professor in the Department of Obstetrics, Gynecology, and Reproductive Sciences at the Yale School of Medicine, anecdotal evidence and studies suggest that hormones likely play a role.

Keyword: Sleep; Hormones & Behavior
Link ID: 28000 - Posted: 09.22.2021

By Nicholas Bakalar Electroconvulsive therapy, or ECT, can be effective for the treatment of major depression and is just as safe as antidepressant drugs combined with psychotherapy, a large new study concludes. The procedure, once referred to as electroshock therapy, has a controversial and largely unfavorable history. This was partly due to inaccurate portrayals in popular books and films like “One Flew Over the Cuckoo’s Nest,” and partly the result of real problems with the earliest versions of the procedure, which used strong electrical currents and no anesthesia. Today, ECT is performed under general anesthesia, and the doctor, working with an anesthesiologist and a nurse, applies a weak electric current to the brain (usually about 0.8 amperes at 120 volts) for one to six seconds. This causes a seizure inside the brain, but because of the anesthesia, the patient does not experience muscular contractions. The seizure leads to brain changes that relieve symptoms of depression and certain other mental illnesses. Usually, doctors administer a series of ECT treatments over a period of days or weeks. The only painful part of the procedure is the insertion of an intravenous line before anesthesia. There can be side effects afterward, including temporary memory loss, confusion or transitory headaches and muscle aches. Doctors debate whether ECT can cause long-term memory problems distinct from the memory problems that can be caused by depression itself. For this new study, published in Lancet Psychiatry, Canadian researchers used the records of 10,016 adults whose depression was severe enough that they spent three or more days in the hospital. Half of them had received ECT, while the other half were treated with drugs and psychotherapy. Their average age was 57, and about two-thirds were women. The researchers tracked how each group fared in the 30 days after they were discharged from the hospital. © 2021 The New York Times Company

Keyword: Depression
Link ID: 27999 - Posted: 09.18.2021

Abby Olena Delivering anything therapeutic to the brain has long been a challenge, largely due to the blood-brain barrier, a layer of cells that separates the vessels that supply the brain with blood from the brain itself. Now, in a study published August 12 in Nature Biotechnology, researchers have found that double-stranded RNA-DNA duplexes with attached cholesterol can enter the brains of both mice and rats and change the levels of targeted proteins. The results suggest a possible route to developing drugs that could target the genes implicated in disorders such as muscular dystrophy and amyotrophic lateral sclerosis (ALS). “It’s really exciting to have a study that’s focused on delivery to the central nervous system” with antisense oligonucleotides given systemically, says Michelle Hastings, who investigates genetic disease at the Rosalind Franklin University of Medicine and Science in Chicago and was not involved in the study. The authors “showed that it works for multiple targets, some clinically relevant.” In 2015, Takanori Yokota of Tokyo Medical and Dental University and colleagues published a study showing that a so-called heteroduplex oligonucleotide (HDO)—consisting of a short chain of both DNA and an oligonucleotide with modified bases paired with complementary RNA bound to a lipid on one end—was successful at decreasing target mRNA expression in the liver. Yokota’s team later joined forces with researchers at Ionis Pharmaceuticals to determine whether HDOs could cross the blood-brain barrier and target mRNA in the central nervous system. © 1986–2021 The Scientist.

Keyword: Genes & Behavior; ALS-Lou Gehrig's Disease
Link ID: 27998 - Posted: 09.18.2021

By Joshua Rapp Learn Giraffes don’t fight much, says Jessica Granweiler, a master’s student at the University of Manchester in England who studies nature’s tallest mammals. When they do, look out. “Fighting is extremely rare because it’s extremely violent,” Ms. Granweiler said. When older adult males joust for territory or mating rights, their hornlike pairs of ossicones thrust with the force of their long necks and can cut into their opponents’ flesh, wounding and sometimes even killing a combatant. But some forms of giraffe dueling serve other purposes. In a study published last month in the journal Ethology, Ms. Granweiler and her colleagues reported some discoveries about sparring behavior that help giraffes establish social hierarchies. They showed that the animals didn’t take advantage of smaller members of their herds, but rather practiced their head butts with males of similar stature in ways that to a human might even appear fair or honorable. Such findings could aid in the conservation of the dwindling populations of the animals. Ms. Granweiler and her colleagues observed social behavior in giraffes at the small Mogalakwena River Reserve in South Africa from November 2016 to May 2017. They began to record the details of these fights — basically a who-fought-who, and how in the giraffe world. They were surprised to find that giraffes, like humans, can be righties or southpaws when it comes to sparring. Even the youngest animals showed a clear preference, although unlike humans it seemed they were evenly split between lefties and righties. The researchers also noticed that the younger males sparred more with each other, and nearly always chose opponents similar in size to themselves — there wasn’t a lot of bullying going on. A bar brawl effect went on as well, where one sparring match seemed to infect the crowd and prompt more fights around them. © 2021 The New York Times Company

Keyword: Aggression; Sexual Behavior
Link ID: 27997 - Posted: 09.18.2021

by Giorgia Guglielmi Severe infections during early childhood are linked to autism — at least in some boys, a new study in mice and people suggests. The findings were published today in Science Advances. Researchers analyzed the health records of millions of children in the United States and found that boys diagnosed with autism are more likely than non-autistic boys to have had an infection requiring medical attention between age 1 and a half and 4. The study also showed that provoking a strong immune response in newborn mice with only one copy of TSC2, a gene tied to autism, leads to social memory problems in adult male rodents. In people, mutations in TSC2 cause tuberous sclerosis, a condition characterized by non-cancerous tumors and skin growths. About half of all people with tuberous sclerosis also have autism. “If the TSC2 mutation was sufficient to cause autism, then everyone with that mutation would have autism — but they don’t,” says senior investigator Alcino Silva, director of the Integrative Center for Learning and Memory at the University of California, Los Angeles. A child’s chances of having autism rise with severe infections in the child or his mother, previous studies show, but not all children who contract serious infections go on to be diagnosed with autism. The new study is the first to examine the relationship between immune activation and a specific genetic variant tied to autism, Silva says. The findings suggest that genetics and severe infection represent a ‘two-hit’ scenario for autism. © 2021 Simons Foundation

Keyword: Autism; Development of the Brain
Link ID: 27996 - Posted: 09.18.2021

Emma Yasinski Some genetic risk factors for alcohol use disorder overlap with those for neurodegenerative diseases like Alzheimer’s, scientists reported in Nature Communications on August 20. The study, which relied on a combination of genetic, transcriptomic, and epigenetic data, also offers insight into the molecular commonalities among these disorders, and their connections to immune disfunction. “By meshing findings from genome wide association studies . . . with gene expression in brain and other tissues, this new study has prioritized genes likely to harbor regulatory variants influencing risk of Alcohol Use Disorder,” writes David Goldman, a neurogenetics researcher at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), in an email to The Scientist. “Several of these genes are also associated with neurodegenerative disorders—an intriguing connection because of alcohol’s ability to prematurely age the brain.” Over the past several years, researchers have published a handful of massive genome-wide association studies (GWAS) studies identifying loci—regions of the genome that can contain 10 or more individual genes—that likely influence a person’s risk of developing an alcohol use disorder (AUD). In a study published two years ago, Manav Kapoor, a neuroscientist and geneticist at the Icahn School of Medicine at Mount Sinai and first author on the new paper, and his team found evidence that the immune system might be overactive in people with AUD, but the finding left him with more questions. The first was whether excessive drinking directly causes immune dysfunction, or if instead some people’s genetic makeup puts them at risk for both simultaneously. The second was which of the dozen or so genes at each previous GWAS-identified locus actually influences drinking behaviors. Lastly, he wanted to know if there is a genetic difference between people who consume higher numbers of alcoholic beverages per week but are not diagnosed with AUD and those who have received the diagnosis. © 1986–2021 The Scientist.

Keyword: Alzheimers; Genes & Behavior
Link ID: 27995 - Posted: 09.18.2021

By Kim Tingley It’s simple, we are often told: All you have to do to maintain a healthy weight is ensure that the number of calories you ingest stays the same as the number of calories you expend. If you take in more calories, or energy, than you use, you gain weight; if the output is greater than the input, you lose it. But while we’re often conscious of burning calories when we’re working out, 55 to 70 percent of what we eat and drink actually goes toward fueling all the invisible chemical reactions that take place in our body to keep us alive. “We think about metabolism as just being about exercise, but it’s so much more than that,” says Herman Pontzer, an associate professor of evolutionary anthropology at Duke University. “It’s literally the running total of how busy your cells are throughout the day.” Figuring out your total energy expenditure tells you how many calories you need to stay alive. But it also tells you “how the body is functioning,” Pontzer says. “There is no more direct measure of that than energy expenditure.” Though scientists have been studying metabolism for at least a century, they have not been able to measure it precisely enough — in real-world conditions, in enough people, across a broad-enough age range — to see how it changes throughout the human life span. It is clear that the bigger someone is, the more cells they have, and thus the more total calories they burn per day. But it has been much harder to assess whether variables like age, sex, lifestyle and illness influence our rate of energy expenditure. This lack of data led to assumptions rooted in personal experience: for instance, that significant hormonal changes like those that take place during puberty and menopause cause our metabolism to speed up or slow down, prompting us to burn more or fewer calories per day; or that men have inherently faster metabolisms than women, because they seem able to shed pounds more easily; or that our energy expenditure slows in midlife, initiating gradual and inevitable weight gain. “I’m in my 40s; I feel different than I did in my 20s — I buy it, too,” Pontzer says. “All that intuition was never backed up by data. It just seemed so sure.” © 2021 The New York Times Company

Keyword: Obesity
Link ID: 27994 - Posted: 09.15.2021

David Kleinfeld My colleagues and I recently found that we were able to train mice to voluntarily increase the size and frequency of seemingly random dopamine impulses in their brains. Conventional wisdom in neuroscience has held that dopamine levels change solely in response to cues from the world outside of the brain. Our new research shows that increases in dopamine can also be driven by internally mediated changes within the brain. Dopamine is a small molecule found in the brains of mammals and is associated with feelings of reward and happiness. In 2014, my colleagues and I invented a new method to measure dopamine in real time in different parts of the brains of mice. Using this new tool, my former thesis student, Conrad Foo, found that neurons in the brains of mice release large bursts of dopamine – called impulses – for no easily apparent reason. This occurs at random times, but on average about once a minute. Pavlov was famously able to train his dogs to salivate at the sound of a bell, not the sight of food. Today, scientists believe that the bell sound caused a release of dopamine to predict the forthcoming reward. If Pavlov’s dogs could control their cue-based dopamine responses with a little training, we wondered if our mice could control their spontaneous dopamine impulses. To test this, our team designed an experiment that rewarded mice if they increased the strength of their spontaneous dopamine impulses. The mice were able to not only increase how strong these dopamine releases were, but also how often they occurred. When we removed the possibility of a reward, the dopamine impulses returned to their original levels. In the 1990s, neuroscientist Wolfram Schultz discovered that an animal’s brain will release dopamine if the animal expects a reward, not just when receiving a reward. This showed that dopamine can be produced in response to the expectation of a reward, not just the reward itself – the aforementioned modern version of Pavlov’s dog. © 2010–2021, The Conversation US, Inc.

Keyword: Drug Abuse; Learning & Memory
Link ID: 27993 - Posted: 09.15.2021