ByEmily Underwood When two male mice meet in a confined space, the rules of engagement are clear: The lower ranking mouse must yield. But when these norms go out the window—say, when researchers rig such an encounter to favor the weakling—it sends the higher ranking male into a depressionlike spiral. That’s the conclusion of a new neuroimaging study that reveals how the mouse brain responds to an unexpected loss of social status, which has been shown to be a major risk factor for depression in humans, particularly men. The new study’s approach is “clever and powerful,” says Neir Eshel, a neuroscientist and psychiatrist at Stanford University who wasn’t involved in the work. But he cautions more work is needed to extend the results to our own species. Groups of mice live in hierarchies, both in the lab and the wild. In the lab, though, the highest ranking males form particularly despotic regimes. One or more dominant “alpha mice” will have privileged access to food and females. They can pee wherever they please, rather than in the designated corner reserved for commoners. Hailan Hu, a neuroscientist at the Zhejiang University School of Medicine, wanted to know what would happen in the brains of these mousy muckety-mucks when their pecking order was upended. She and colleagues set up a battle of wills, designed to avoid any actual fighting or bloodshed. Ten times a day, over 4 days, the researchers put a dominant mouse nose-to-nose with a subordinate in a clear, narrow tube. Then they blocked the lower ranked rodent’s exit, leaving it no choice but to advance on its superior. At first, the dominant mice resisted the upstarts and held their ground. But by the fourth day, they were retreating voluntarily from their opponents after only a few seconds. In doing so, the mouse kings also fell in social status and lost their high-ranking perks, including VIP access to a warm nest in the corner.

Keyword: Aggression; Depression
Link ID: 28651 - Posted: 02.01.2023

By Joanna Thompson People often think they know what causes chronic depression. Surveys indicate that more than 80% of the public blames a “chemical imbalance” in the brain. That idea is widespread in pop psychology and cited in research papers and medical textbooks. Listening to Prozac, a book that describes the life-changing value of treating depression with medications that aim to correct this imbalance, spent months on the New York Times bestseller list. The unbalanced brain chemical in question is serotonin, an important neurotransmitter with fabled “feel-good” effects. Serotonin helps regulate systems in the brain that control everything from body temperature and sleep to sex drive and hunger. For decades, it has also been touted as the pharmaceutical MVP for fighting depression. Widely prescribed medications like Prozac (fluoxetine) are designed to treat chronic depression by raising serotonin levels. Yet the causes of depression go far beyond serotonin deficiency. Clinical studies have repeatedly concluded that the role of serotonin in depression has been overstated. Indeed, the entire premise of the chemical-imbalance theory may be wrong, despite the relief that Prozac seems to bring to many patients. If you were still of the opinion that it was simply a chemical imbalance of serotonin, then yeah, it’s pretty damning. A literature review that appeared in Molecular Psychiatry in July was the latest and perhaps loudest death knell for the serotonin hypothesis, at least in its simplest form. An international team of scientists led by Joanna Moncrieff of University College London screened 361 papers from six areas of research and carefully evaluated 17 of them. They found no convincing evidence that lower levels of serotonin caused or were even associated with depression. People with depression didn’t reliably seem to have less serotonin activity than people without the disorder. Experiments in which researchers artificially lowered the serotonin levels of volunteers didn’t consistently cause depression. Genetic studies also seemed to rule out any connection between genes affecting serotonin levels and depression, even when the researchers tried to consider stress as a possible cofactor. All Rights Reserved © 2023

Keyword: Depression; Stress
Link ID: 28647 - Posted: 01.27.2023

Hannah Devlin Science correspondent Widely used antidepressants cause “emotional blunting”, according to research that offers new insights into how the drugs may work and their possible side-effects. The study found that healthy volunteers became less responsive to positive and negative feedback after taking a selective serotonin reuptake inhibitor (SSRI) drug for three weeks. The “blunting” of negative emotions could be part of how the drugs help people recover from depression, but could also explain a common side-effect. The work’s senior author, Prof Barbara Sahakian of the University of Cambridge, said: “In a way, this may be in part how they work. They take away some of the emotional pain that people who experience depression feel, but unfortunately it seems that they also take away some of the enjoyment.” The findings could help patients make better informed choices about their medication, she said, but added “there is no doubt that antidepressants are beneficial” for many patients. According to the NHS more than 8.3 million patients in England received an antidepressant drug in 2021-22. SSRIs are among the most widely used, and are effective for the majority of, although not all, patients. Some people on the medication report feeling emotionally dull or no longer finding things as pleasurable, with one study suggesting this applied to 40-60% of people taking the drug. However, it has been unclear whether this symptom is a drug side-effect or a symptom of depression. The latest work suggests that the drug alone can produce emotional blunting. In the study, published in the journal Neuropsychopharmacology, 66 volunteers were given either the SSRI drug, escitalopram, or a placebo for at least 21 days before doing a set of cognitive tests. © 2023 Guardian News & Media Limited

Keyword: Depression; Emotions
Link ID: 28641 - Posted: 01.25.2023

By Daryl Austin My three young daughters like to watch pets doing silly things. Almost daily, they ask to see animal video clips on my phone and are quickly entertained. But once my 7-year-old lets out a belly laugh, the laughter floodgates are opened and her two sisters double over as well. This is just what science would predict. “Laughter is a social phenomenon,” says Sophie Scott, a neuroscientist at University College London who has studied laughter and other human reactions for more than two decades. Scott co-wrote a study showing how the brain responds to the sound of laughter by preparing one’s facial muscles to join in, laying the foundation for laughs to spread from person to person. “Contagious laughter demonstrates affection and affiliation,” Scott says. “Even being in the presence of people you expect to be funny will prime laughter within you.” It’s like yawning Scientists have yet to definitively find a funny bone, but they are revealing nuances about the laugh impulse. Laughter’s positive psychological and physiological responses include lessening depression and anxiety symptoms, increasing feelings of relaxation, improving cardiovascular health, releasing endorphins that boost mood and even increasing tolerance for pain. Laughing has also been shown to lower stress levels. “Cortisol is a stress hormone that laughter lowers,” says Scott, adding that anticipation of laughter also “drops your adrenaline” and the body’s heightened fight-or-flight response. “All of these things contribute to you feeling better when you’ve been laughing,” she says. Because humans are wired to mirror one another, laughs spread around a room just like yawns, says Lauri Nummenmaa, a brain researcher and professor at Aalto University School of Science in Finland whose work appears in a recent special issue on laughter in the journal Royal Society.

Keyword: Emotions
Link ID: 28633 - Posted: 01.18.2023

Kaitlyn Radde Socially isolated older adults have a 27% higher chance of developing dementia than older adults who aren't, a new study by Johns Hopkins researchers found. "Social connections matter for our cognitive health, and it is potentially easily modifiable for older adults without the use of medication," Dr. Thomas Cudjoe, an assistant professor of medicine at Johns Hopkins and a senior author of the study, said in a news release. Published in the Journal of the American Geriatrics Society, the study tracked 5,022 dementia-free U.S. adults who were 65 or older – with an average age of 76 – and not living in a residential care facility. About 23% of participants were socially isolated. Social isolation is defined as having few relationships and few people to interact with regularly. The study measured this based on whether or not participants lived alone, talked about "important matters" with two or more people in the past year, attended religious services or participated in social events. Participants were assigned one point for each item, and those who scored a zero or one were classified as socially isolated. Over the course of nine years, researchers periodically administered cognitive tests. Overall, about 21% of the study participants developed dementia. But among those were who were socially isolated, about 26% developed dementia – compared to slightly less than 20% for those who were not socially isolated. The study did not find significant differences by race or ethnicity. However, more than 70% of the participants in the study were white – with particularly small sample sizes of Hispanic, Asian and Native participants – and the authors call for further research on the topic. © 2023 npr

Keyword: Alzheimers
Link ID: 28631 - Posted: 01.18.2023

By Freda Kreier Living through the COVID-19 pandemic may have matured teens’ brains beyond their years. From online schooling and social isolation to economic hardship and a mounting death count, the last few years have been rough on young people. For teens, the pandemic and its many side effects came during a crucial window in brain development. Now, a small study comparing brain scans of young people from before and after 2020 reveals that the brains of teens who lived through the pandemic look about three years older than expected, scientists say. This research, published December 1 in Biological Psychiatry: Global Open Science, is the first to look at the impact of the pandemic on brain aging. The finding reveals that “the pandemic hasn’t been bad just in terms of mental health for adolescents,” says Ian Gotlib, a clinical neuroscientist at Stanford University. “It seems to have altered their brains as well.” The study can’t link those brain changes to poor mental health during the pandemic. But “we know there is a relationship between adversity and the brain as it tries to adapt to what it’s been given,” says Beatriz Luna, a developmental cognitive neuroscientist at the University of Pittsburgh, who wasn’t involved in the research. “I think this is a very important study that sets the ball rolling for us to look at this.” The roots of this study date back to nearly a decade ago, when Gotlib and his colleagues launched a project in California’s Bay Area to study depression in adolescents. The researchers were collecting information on the mental health of the kids in the study, and did MRI scans of their brains. © Society for Science & the Public 2000–2023.

Keyword: Development of the Brain; Stress
Link ID: 28620 - Posted: 01.04.2023

By Erin Blakemore Can the human body betray a lie? In the 1920s, inventors designed a device they said could detect deception by monitoring a subject’s breathing and blood pressure. “The Lie Detector,” an American Experience documentary that premieres Tuesday on PBS, delves into the history of the infamous device. In the century after its invention, the lie detector’s popularity skyrocketed. And despite a checkered legacy, polygraph tests are still regularly used by law enforcement and some employers. The documentary tells a story of honest intentions and sinister consequences. John Larson, one of its inventors, was a medical student and law enforcement officer in search of more humane methods of policing and interrogation. He piggybacked off new scientific and psychological concepts to create the device in 1921. The technologies Larson and his co-inventors used were still in their infancy, and the idea that people produce measurable, consistent physical symptoms when they lie was unproved. It still is. Polygraph protocols have evolved, but the devices’ detractors say they measure only anxiety, not truthfulness. And even as major organizations have raised questions about the scientific validity of the tests and federal laws have prohibited most private employers from requiring them, the idea that dishonesty can be measured through physical testing remains widespread. The documentary suggests that the polygraph tests’ popularity was tied more to publicity than accuracy — and over time, Larson’s vision was turned on its head as polygraphs were used to intimidate, incarcerate and interrogate people. With the help of expert interviews and a kaleidoscope of historical footage and imagery, director Rob Rapley tracks the tale of an invention its own creator compared to Frankenstein’s monster.

Keyword: Stress
Link ID: 28618 - Posted: 01.04.2023

By Shayla Love On Valentine’s Day in 2016, Anne Lantoine received not flowers, but divorce papers. In the months preceding, she had been preparing for her family’s move from France to Canada—or so she thought. She arrived in Quebec early with one of her three children, who was preparing to start college there, while the other two remained in Europe for school. Her husband stayed behind to manage the sale of their house in Marseille. Then the realtors began to complain, through a barrage of calls and emails, to Lantoine. Her husband was not acting like a man who wanted his house sold. He wasn’t answering phone calls and was never available for showings. In January 2016, Lantoine called him after yet another complaint from a realtor. The next morning, he sent her an email with a notice for a court hearing, and she discovered her husband had actually filed for divorce, without telling her, months earlier. That February, she finally got the paperwork, not from her husband, but from her real estate agent. “It was not my last shock,” Lantoine, now 59, recalls. “I also discovered that my husband’s mistress was living in my home.” These revelations were a huge blow practically: It disrupted the immigration paperwork, and Lantoine and her daughter lost their visa applications. But the searing pain was in the betrayal and deceit. “I became very anxious and had constant nightmares,” she says. “I was tired all the time and had panic attacks each time I opened my mail or my emails, or when I had an unidentified phone call.” Though the details of each case vary, romantic betrayal through infidelity, abandonment, or emotional manipulation can upend one’s life in an instant. For Lantoine, her future plans, and the person they were attached to, were suddenly gone, and her functioning along with them. © 2022 NautilusThink Inc, All rights reserved.

Keyword: Stress; Learning & Memory
Link ID: 28612 - Posted: 12.28.2022

Kristine Zengeler Many neurodegenerative diseases, or conditions that result from the loss of function or death of brain cells, remain largely untreatable. Most available treatments target just one of the multiple processes that can lead to neurodegeneration, which may not be effective in completely addressing disease symptoms or progress, if at all. But what if researchers harnessed the brain’s inherent capabilities to cleanse and heal itself? My colleagues and I in the Lukens Lab at the University of Virginia believe that the brain’s own immune system may hold the key to neurodegenerative disease treatment. In our research, we found a protein that could possibly be leveraged to help the brain’s immune cells, or microglia, stave off Alzheimer’s disease. No available treatments for neurodegenerative diseases stop ongoing neurodegeneration while also helping affected areas in the body heal and recuperate. In terms of failed treatments, Alzheimer’s disease is perhaps the most infamous of neurodegenerative diseases. Affecting more than 1 in 9 U.S. adults 65 and older, Alzheimer’s results from brain atrophy with the death of neurons and loss of the connections between them. These casualties contribute to memory and cognitive decline. Billions of dollars have been funneled into researching treatments for Alzheimer’s, but nearly every drug tested to date has failed in clinical trials.

Keyword: Alzheimers; Neuroimmunology
Link ID: 28590 - Posted: 12.13.2022

By Ingrid Wickelgren  Recurrent intrusive memories lie at the heart of certain mental illnesses, including post-traumatic stress disorder and obsessive-compulsive disorder. Clinicians often treat these conditions with “exposure therapy.” They gradually and gently re-expose patients to feared stimuli or simulations—from reminders of active combat to germs on a toilet—teaching the brain to become accustomed to the stimuli and to decouple them from danger. But exposure therapy has drawbacks. “Facing these traumatic memories is painful to patients,” says Yingying Wang, a cognitive psychologist at Zhejiang University in China. “These treatments suffer from a very high dropout rate.” Wang and her colleagues have taken a first step toward developing a more benign way to dim traumatic memories. Their proof-of-concept study involves subliminal exposure to cues to those memories after putting the brain in a state in which it is likely to forget. The new findings present a new spin on a form of active forgetting in which people learn to suppress memories by practicing not thinking about them in the presence of reminders. In various studies, participants have memorized pairs of words such as needle-doctor or jogger-collie and then practiced either thinking or not thinking about the second word when the first word (the reminder) appears. Practicing not thinking about the second word has led to forgetting. The mechanism for this effect centers on the brain’s main memory hub, the hippocampus. Psychologists have discovered that suppressing memory retrieval puts the hippocampus in a degraded functional state. This state lasts for a small window of time—at least 10 seconds but potentially much longer—casting what researchers have dubbed an “amnesic shadow” that leads to poor memory for other things that happen within it. So when people suppress neutral word pairs, they put their brain into a state in which they are likely to forget new experiences. © 2022 Scientific American,

Keyword: Stress; Learning & Memory
Link ID: 28586 - Posted: 12.10.2022

ByErik Stokstad Toxoplasma gondii is sometimes called the “mind control” parasite: It can infect the brains of animals and mess with their behavior in ways that may kill the host but help ensure the parasite’s spread. But now, researchers have found that infected wolves may actually benefit from those mind-altering tricks. A Toxoplasma infection, they found, makes wolves bolder and more likely to become pack leaders or disperse into other habitats, giving them more opportunity to reproduce. "We’ve really underestimated some of the consequences this parasite has,” says Eben Gering, a biologist at Nova Southeastern University who was not involved in the work. “The findings probably represent the tip of the iceberg concerning the parasite’s significance to the dynamics of wild ecosystems.” T. gondii, a single-celled parasite, only reproduces in domesticated cats and other felids. Infected cats excrete spore-packed oocysts in their feces, which can survive on plants or in soil or water. They can also persist in undercooked meat of livestock or game. When a host—humans included—consumes an oocyst, the spores are released and spread into the brain and muscles, forming new cysts. Worldwide, about one in four people is infected. Usually, the immune system keeps the parasite in check, but it can cause spontaneous abortion and other serious problems during pregnancy. It's long been known that rodents infected with Toxoplasma lose their fear of predators. Cysts in the brain somehow increase dopamine and testosterone, boosting boldness and risk-taking and increasing the chance the host will be eaten by cats. "These parasites are using some generic mind control or personality control that helps them fulfill their lifecycle," says Jaap de Roode, a biologist at Emory University who was not involved in the new study. "And that has all sorts of interesting consequences that we may not even have thought of before.” The consequences aren’t limited to rodents. In 2016, researchers in Gabon found that Toxoplasma-infected captive chimpanzees lost their aversion to leopard urine. And last year, another team described how Toxoplasma-infected hyena cubs in Kenya venture closer to lions, making them more likely to be killed.

Keyword: Aggression; Emotions
Link ID: 28583 - Posted: 12.06.2022

By Roni Caryn Rabin Deaths due to substance abuse, particularly of alcohol and opioids, rose sharply among older Americans in 2020, the first year of the coronavirus pandemic, as lockdowns disrupted routines and isolation and fear spread, federal health researchers reported on Wednesday. Alcohol and opioid deaths remained far less common among older people than among those middled-aged and younger, and rates had been rising in all groups for years. But the pronounced uptick — another data point in the long list of pandemic miseries — surprised government researchers. Deaths from opioids increased among Americans aged 65 and older by 53 percent in 2020 over the previous year, the National Center for Health Statistics found. Alcohol-related deaths, which had already been rising for a decade in this age group, rose by 18 percent. “The rate of alcohol deaths in older people is much lower than for younger adults, but the change caught our eye,” said Ellen Kramarow, a health statistician at the center and the lead author of the report, which analyzed death certificate data. Overdose deaths from synthetic opioids account for fewer than 1 percent of deaths in people over 65, Dr. Kramarow noted. “But the shape of the curve jumped out at us,” she said. Physiological changes that occur with aging leave older adults more vulnerable to the ill effects of alcohol and drugs, as metabolism and excretion of substances slow down, increasing the risk of toxicity. Smaller amounts have bigger effects, researchers have found. Alcohol and opioids can interact poorly with prescription medications that many older adults take for common conditions like hypertension, diabetes and mood disorders. Misuse can lead to falls and injuries, exacerbate underlying medical conditions and worsen declines in cognition. © 2022 The New York Times Company

Keyword: Drug Abuse; Stress
Link ID: 28581 - Posted: 12.06.2022

Nicola Davis Science correspondent The brains of teenagers who lived through Covid lockdowns show signs of premature ageing, research suggests. The researchers compared MRI scans of 81 teens in the US taken before the pandemic, between November 2016 and November 2019, with those of 82 teens collected between October 2020 and March 2022, during the pandemic but after lockdowns were lifted. After matching 64 participants in each group for factors including age and sex, the team found that physical changes in the brain that occurred during adolescence – such as thinning of the cortex and growth of the hippocampus and the amygdala – were greater in the post-lockdown group than in the pre-pandemic group, suggesting such processes had sped up. In other words, their brains had aged faster. “Brain age difference was about three years – we hadn’t expected that large an increase given that the lockdown was less than a year [long],” said Ian Gotlib, a professor of psychology at Stanford University and first author of the study. Writing in the journal Biological Psychiatry: Global Open Science, the team report that the participants – a representative sample of adolescents in the Bay Area in California – originally agreed to take part in a study looking at the impact of early life stress on mental health across puberty. As a result, participants were also assessed for symptoms of depression and anxiety. The post-lockdown group self-reported greater mental health difficulties, including more severe symptoms of anxiety, depression and internalising problems. © 2022 Guardian News & Media

Keyword: Stress; Development of the Brain
Link ID: 28578 - Posted: 12.03.2022

By Virginia Hughes CRANSTON, R.I. — Audrey Pirri, 16, had been terrified of vomiting since she was a toddler. She worried every time she shared a meal with family or friends, restricting herself to “safe” foods like pretzels and salad that wouldn’t upset her stomach, if she ate at all. She was afraid to ride in the car with her brother, who often got carsick. She fretted for hours about an upcoming visit to a carnival or stadium — anywhere with lots of people and their germs. But on a Tuesday evening in August, in her first intensive session of a treatment called exposure therapy, Audrey was determined to confront one of the most potent triggers of her fear: a set of rainbow polka dot sheets. For eight years she had avoided touching the sheets, ever since the morning when she woke up with a stomach bug and vomited on them. Now, surrounded by her parents, a psychologist and a coach in her pale pink bedroom, she pulled the stiff linens from her dresser, gingerly slid them over the mattress and sat down on top. “You ready to repeat after me?” said Abbe Garcia, the psychologist. “I guess,” Audrey replied softly. “‘I am going to sleep on these sheets tonight,’” Dr. Garcia began. Audrey repeated the phrase. “‘And I might throw up,’” Dr. Garcia said. Audrey paused for several long seconds, her feet twitching and eyes welling with tears, as she imagined herself vomiting. She inhaled deeply and hurried out the words: “And I might throw up.” One in 11 American children has an anxiety disorder, and that figure has been growing steadily for the past two decades. The social isolation, family stress and relentless news of tragedy during the pandemic have only exacerbated the problem. But Audrey is one of the relatively few children to have tried exposure therapy. The decades-old treatment, which is considered a gold-standard approach for tackling anxiety, phobias and obsessive-compulsive disorder, encourages patients to intentionally face the objects or situations that cause them the most distress. A type of cognitive behavioral therapy, exposure often works within months and has minimal side effects. But financial barriers and a lack of providers have kept the treatment out of reach for many. © 2022 The New York Times Company

Keyword: Stress; Learning & Memory
Link ID: 28564 - Posted: 11.23.2022

By Aimee Cunningham The death rate from alcohol use rose sharply in the United States in the first year of the pandemic. From 2019 to 2020, the rate of alcohol-induced deaths climbed 26 percent, from 10.4 per 100,000 people to 13.1 per 100,000, researchers report in a National Center for Health Statistics data brief published November 4. The rate of alcohol-induced deaths has generally increased yearly for the last two decades, but the annual uptick tended to be 7 percent or less. Deaths from alcoholic liver disease, which includes hepatitis and cirrhosis, were the most common driver of the increased rate. Deaths from mental and behavioral disorders due to alcohol use — mortality from dependence syndrome or withdrawal, for example — were the second most frequent contributor. The death rate from alcohol use jumped 26 percent overall from 2019 to 2020, a marked increase from previous years. Other researchers have reported that adults were drinking more frequently, and more heavily, early in the pandemic compared with the year before. There is also evidence of an increase in cases of alcoholic liver disease. A study at Johns Hopkins Hospital in Baltimore reported that 2.3 times as many patients with severe alcoholic liver disease and with recent unhealthy drinking were referred to their liver transplant center from July to December of 2020 compared with those months in 2019. © Society for Science & the Public 2000–2022.

Keyword: Drug Abuse; Stress
Link ID: 28539 - Posted: 11.05.2022

Vanessa Rom When put to the test, bees have proved over and over again that they've got a lot more to offer than pollinating, making honey and being fiercely loyal to a queen. The industrious insects can count and alter their behavior when things seem difficult, and now some scientists say there's proof they also like to play. A study recently published in Animal Behavior suggests that bumblebees, when given the chance, like to fool around with toys. Researchers from Queen Mary University of London conducted an experiment in which they set up a container that allowed bees to travel from their nest to a feeding area. But along the way, the bees could opt to pass through a separate section with a smattering of small wooden balls. Over 18 days, the scientists watched as the bees "went out of their way to roll wooden balls repeatedly, despite no apparent incentive to do so." The finding suggests that like humans, insects also interact with inanimate objects as a form of play. Also similar to people, younger bees seemed to be more playful than adult bees. In this experiment from researchers at Queen Mary University of London, bumblebees, especially young ones, appeared to show they liked to cling to wooden balls twice their size and roll them around just for the fun of it. "This research provides a strong indication that insect minds are far more sophisticated than we might imagine," Lars Chittka, a professor of sensory and behavioral ecology at Queen Mary University of London, who led the study, said in a statement. Earlier studies have shown that the black and yellow bugs are willing to learn new tricks in exchange for food or other rewards, so in this case Chittka and his team set out to create conditions that would eliminate external variables. They made sure that the bees had acclimated to their new home and that their environment was stress free. © 2022 npr

Keyword: Emotions; Evolution
Link ID: 28538 - Posted: 11.05.2022

By Veronique Greenwood Anyone who’s had a shady oyster or a mushroom soup that didn’t sit well remembers the ominous queasiness heralding impending bad times. Bacteria release toxins that start the body’s process of speedily evacuating the contents of the stomach. It’s a protective mechanism of sorts — getting rid of the invaders en masse is probably helpful in the long term, even if it’s unpleasant in the short. But it has remained something of a mystery how the brain gets the alarm signal, then sends another one to tell the stomach to initiate a technicolor yawn. Your next bout of food poisoning isn’t the only reason to understand this particular neural pathway. Figuring out how to counter it could be helpful for people who develop nausea caused by chemotherapy medication and other drugs. As if fighting cancer isn’t painful and scary enough, patients are often so turned off by food that keeping their weight up becomes a major struggle. In a new study, researchers report that both bacteria and chemotherapy drugs appear to trigger the same molecular pathways in the gut. The findings, which were based on experiments with mice and published Tuesday in the journal Cell, showed that a bacterial toxin and a chemo medication both set in motion a cascade of similar neural messages that cause queasiness. Choosing mice for the study was unusual. Mice, it turns out, can’t puke — a little foible that typically makes it difficult to use them to study nausea. Researchers have used cats and dogs in the past, but the biology of mice in general is so much better understood, with much better tools available to scientists to do so. Cao Peng, a professor at Tsinghua University in Beijing, and his colleagues wondered whether mice might still be capable of feeling ill in the way people do after ingesting a chemo drug or a bad salad — or close enough, anyway, that researchers could use the creatures to understand the origins of the sensation. © 2022 The New York Times Company

Keyword: Obesity; Stress
Link ID: 28537 - Posted: 11.02.2022

By Sandra G. Boodman For years Carter Caldwell had adamantly rejected doctors’ recommendations that he consider surgery to treat the frequent, uncontrolled seizures that were ravaging his brain. Caldwell, who had developed epilepsy when he was 28, regarded the operation that involved removing a portion of his brain as too big a risk — particularly because doctors weren’t sure what was causing the seizures and couldn’t pinpoint their location. Instead the Philadelphia business executive had organized his life to minimize certain foreseeable hazards: He lived downtown and didn’t drive. He didn’t push his toddler’s stroller. When taking the train he stood at the back of the platform — nowhere near the tracks in case he suddenly collapsed. His colleagues at work knew about his condition. But that calculus changed abruptly in November 2014. Caldwell, accompanied by his wife, Connie, and their 3-year-old son, was atop a hill at Pennsylvania’s Valley Forge National Historical Park posing for photos for a holiday card. Without warning he began an awkward shuffling walk that signified the onset of a seizure. Then he lost consciousness and fell head first down a rocky 15-foot embankment before landing at the edge of a stream. “Thankfully,” he said, “I didn’t roll into the stream.” He spent the next 2 1/2 weeks in a nearby hospital where a plastic surgeon performed multiple operations on his broken jawbone, lacerated cheek and shattered eye socket. “I remember him saying, ‘I can’t believe this happened in front of my family,’ ” recalled his longtime neurologist John R. Pollard, formerly associate director of the epilepsy center at the University of Pennsylvania. Pollard had warned Caldwell that his intractable seizures, which had proved resistant to numerous medications, placed him at risk for sudden death or serious injury. In September 2015 a successful operation unmasked the very unusual cause of Caldwell’s seizures, a culprit experts had long suspected but had been unable to definitively identify.

Keyword: Epilepsy; Emotions
Link ID: 28518 - Posted: 10.19.2022

Inside a Berlin neuroscience lab one day last year, Subject 1 sat on a chair with their arms up and their bare toes pointed down. Hiding behind them, with full access to the soles of their feet, was Subject 2, waiting with fingers curled. At a moment of their choosing, Subject 2 was instructed to take the open shot: Tickle the hell out of their partner. In order to capture the moment, a high-speed GoPro was pointed at Subject 1’s face and body. Another at their feet. A microphone hung nearby. As planned, Subject 1 couldn’t help but laugh. The fact that they couldn’t help it is what has drawn Michael Brecht, leader of the research group from Humboldt University, to the neuroscience of tickling and play. It’s funny, but it’s also deeply mysterious—and understudied. “It’s been a bit of a stepchild of scientific investigation,” Brecht says. After all, brain and behavior research typically skew toward gloom, topics like depression, pain, and fear. “But,” he says, “I think there are also more deep prejudices against play—it's something for children.” The prevailing wisdom holds that laughter is a social behavior among certain mammals. It’s a way of disarming others, easing social tensions, and bonding. Chimps do it. Dogs and dolphins too. Rats are the usual subjects in tickling studies. If you flip ’em over and go to town on their bellies, they’ll squeak at a pitch more than twice as high as the limit of human ears. But there are plenty of lingering mysteries about tickling, whether among rats or people. The biggest one of all: why we can’t tickle ourselves. “If you read the ancient Greeks, Aristotle was wondering about ticklishness. Also Socrates, Galileo Galilei, and Francis Bacon,” says Konstantina Kilteni, a cognitive neuroscientist who studies touch and tickling at Sweden’s Karolinska Institutet, and who is not involved in Brecht’s work. We don’t know why touch can be ticklish, nor what happens in the brain. We don’t know why some people—or some body parts—are more ticklish than others. “These questions are very old,” she continues, “and after almost 2,000 years, we still really don’t have the answer.” © 2022 Condé Nast.

Keyword: Attention; Emotions
Link ID: 28504 - Posted: 10.08.2022

By Erin Blakemore Empathy and generosity are two traits that arguably make the world go ‘round. But a study suggests that the willingness to help collapses when people get too little — or poor — sleep. To see how sleep affects how much humans help one another, researchers conducted three experiments designed to examine the issue from the individual to the societal scale. Their results are published in PLOS Biology. In the first experiment, researchers performed functional magnetic resonance imaging scans of the brain and asked questions to 24 adults after eight hours of sleep and after a night with no sleep. When they were well rested, the participants scored well on a helping behavior test. But after sleep deprivation, 78 percent had less of a desire to help others, even when it came to friends and family. The scans showed that areas of the brain associated with social cognition — our thought processes related to other people — were less active with sleep deprivation. The second experiment tracked 136 healthy adults over four nights and asked them questions about helping the following day. The effect held for them, too, and those who reported worse sleep quality scored worse on the tests. Just one hour of extra sleep each night can lead to better eating habits To test the effects on a societal level, the researchers then looked at a database of 3 million charitable donations given between 2001 and 2016. They found that immediately following the beginning of daylight saving time — a notorious sleep disrupter — donations dropped 10 percent. The effect wasn’t found in data from Hawaii or Arizona, however; neither observe DST. Nor did the shift back to standard time have such an association with donations.

Keyword: Sleep; Emotions
Link ID: 28503 - Posted: 10.08.2022