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By Laura Dattaro Steven McCarroll just wanted to compare how different cell types express genes in people with and without schizophrenia. But when he sequenced the transcriptomes of more than 1 million cortical cells from 191 postmortem brains, what leapt out from the data went far beyond his simple case-control comparison: Astrocytes and neurons from all of the brains coordinate their expression of certain genes needed for healthy synapses, a relationship the team dubbed the Synaptic Neuron-and-Astrocyte Program (SNAP) and described in a paper published in Nature today. “The data led us to something much more exciting and surprising than what we set out to do,” says McCarroll, professor of biomedical science and genetics at Harvard Medical School. SNAP is an intricate dance, McCarroll and his colleagues found: The more a person’s neurons express synaptic genes, so too do their astrocytes, but this coordination wanes in older people and those with schizophrenia. Because astrocytes — a type of glial cell — and neurons are in constant communication and the findings are correlational, it’s unclear which cell type choreographs this dance. But other evidence suggests that astrocytes take the lead, says Stephen Quake, professor of bioengineering at Stanford University, who was not involved in McCarroll’s work. In mice trained to fear a foot shock, for example, neurons involved in memory formation express neurotensin, whereas astrocytes express a receptor for it, Quake and his colleagues reported last month in Nature. But when they inhibited the animals’ astrocytes during fear training, the mice performed worse on memory tests, suggesting those cells play an active role in long-term memory formation, Quake says — and govern the relationship McCarroll found. © 2024 Simons Foundation

Keyword: Learning & Memory; Glia
Link ID: 29183 - Posted: 03.07.2024

By Lisa Sanders, M.D. Surrounded by the detritus of a Thanksgiving dinner, the woman was loading the dishwasher when a loud thump thundered through the house. She hurried out of the kitchen to find her husband of 37 years sitting on the second-floor landing. Her son and son-in-law, an emergency-room doctor, crouched at his side. Her husband protested that he was fine, then began to scooch himself on his bottom into the bedroom. The two young men helped him to his feet. The man’s body shook with a wild tremor that nearly knocked him down again. “I was getting into bed and fell,” he explained — though the bed was too far away to make this at all likely. “Get some sleep,” the woman said gently once her husband was settled in the bed. “We’ll go to the hospital in the morning.” Her daughter and son-in-law had arrived that morning and already mentioned the change they noticed in the 70-year-old senior. The normally gregarious man was oddly quiet. And the tremor he had for as long as they could remember was much more prominent. His hands shook so much he had trouble using his fork and ended up eating much of his Thanksgiving dinner with his fingers. And now this fall, this confusion — they were worried. His wife was also worried. Just after Halloween, she traveled for business, and when she came back, her husband was much quieter than usual. Even more concerning: When he spoke, he didn’t always make sense. “Have you had a stroke?” she asked her first day home. He was fine, he insisted. But a few days later she came home from work to find his face covered with cuts. He was shaving, he said, but his hand shook so much that he kept cutting himself. “There is something wrong with me,” he acknowledged. It was Thanksgiving week, but she was able to get him an appointment at his doctor’s office the next day. They were seen by the physician assistant (P.A.). She was kind, careful and thorough. After hearing of his confusion, she asked the man what day it was. “Friday?” he offered uncertainly. It was Wednesday. Could he touch his finger to his nose and then to her finger, held an arm’s length away? He could not. His index finger carved jagged teeth in the air as he sought his own nose then stretched to touch her finger. And when she asked him to stand, his entire body wobbled dangerously. “It’s all happened so quickly,” the man’s wife said. The P.A. reviewed his lab tests. They were all normal. She then ordered an M.R.I. of the brain. That, she explained, should give them a better idea of what direction to take. But, she added, if he falls or seems © 2024 The New York Times Company

Keyword: Neurotoxins; Movement Disorders
Link ID: 29182 - Posted: 03.07.2024

By Veronique Greenwood It can be hard to tell, at first, when a cell is on the verge of self-destruction. It appears to be going about its usual business, transcribing genes and making proteins. The powerhouse organelles called mitochondria are dutifully churning out energy. But then a mitochondrion receives a signal, and its typically placid proteins join forces to form a death machine. They slice through the cell with breathtaking thoroughness. In a matter of hours, all that the cell had built lies in ruins. A few bubbles of membrane are all that remains. “It’s really amazing how fast, how organized it is,” said Aurora Nedelcu, an evolutionary biologist at the University of New Brunswick who has studied the process in algae. Apoptosis, as this process is known, seems as unlikely as it is violent. And yet some cells undergo this devastating but predictable series of steps to kill themselves on purpose. When biologists first observed it, they were shocked to find self-induced death among living, striving organisms. And although it turned out that apoptosis is a vital creative force for many multicellular creatures, to a given cell it is utterly ruinous. How could a behavior that results in a cell’s sudden death evolve, let alone persist? The tools for apoptosis, molecular biologists have found, are curiously widespread. And as they have sought to understand its molecular process and origins, they’ve found something even more surprising: Apoptosis can be traced back to ancient forms of programmed cell death undertaken by single-celled organisms — even bacteria — that seem to have evolved it as a social behavior. © 2024 the Simons Foundation.

Keyword: Apoptosis; Development of the Brain
Link ID: 29181 - Posted: 03.07.2024

By Emily Anthes Colombia is a bird watcher’s paradise. Its stunningly diverse ecosystems — which include mountain ranges, mangrove swamps, Caribbean beaches and Amazonian rainforests — are home to more avian species than any other country on Earth. So when Hamish Spencer, an evolutionary biologist at the University of Otago in New Zealand, booked a bird-watching vacation in Colombia, he was hoping to spot some interesting and unusual creatures. He got more than he bargained for. During one outing, in early January 2023, the proprietor of a local farm drew his attention to a green honeycreeper, a small songbird that is common in forests ranging from southern Mexico to Brazil. But this particular green honeycreeper had highly unusual plumage. The left side of its body was covered in shimmering spring-green feathers, the classic coloring for females. Its right side, however, was iridescent blue, the telltale marker of a male. The bird appeared to be a bilateral gynandromorph: female on one side and male on the other. “It was just incredible,” Dr. Spencer said. “We were lucky to see it.” Gynandromorphism has been documented in a variety of birds, as well as insects, crustaceans and other organisms. But it’s a relatively rare and poorly understood phenomenon. The bird Dr. Spencer saw in Colombia is only the second known case of bilateral gynandromorphism in a green honeycreeper — and the first documented in the wild. © 2024 The New York Times Compan

Keyword: Sexual Behavior
Link ID: 29180 - Posted: 03.07.2024

By Andrew Jacobs Ibogaine, a formidable hallucinogen made from the root of a shrub native to Central Africa, is not for the timid. It unleashes a harrowing psychedelic trip that can last more than 24 hours, and the drug can cause sudden cardiac arrest and death. But scientists who have studied ibogaine have reported startling findings. According to a number of small studies, between a third and two-thirds of the people who were addicted to opioids or crack cocaine and were treated with the compound in a therapeutic setting were effectively cured of their habits, many after just a single session. Ibogaine appears to provide two seemingly distinct benefits. It quells the agony of opioid withdrawal and cravings and then gives patients a born-again-style zeal for sobriety. Now, after decades in the shadows, and with opioid overdose deaths exceeding 100,000 a year, ibogaine is drawing a surge of fresh interest from researchers who believe it has the potential to treat opioid use disorder. “It’s not an exaggeration to say that ibogaine saved my life, allowed me to make amends with the people I hurt and helped me learn to love myself again,” said Jessica Blackburn, 37, who is recovering from heroin addiction and has been sober for eight years. “My biggest frustration is that more people don’t have access to it.” That’s because ibogaine is illegal in the United States. Patients have to go abroad for ibogaine therapy, often at unregulated clinics that provide little medical oversight. Kentucky and Ohio are considering proposals to spend millions of dollars of opioid settlement money on clinical trials for ibogaine therapy. And federal drug researchers have signaled a willingness to allow the drug to be studied again — more than 40 years after regulators pulled the plug on research over concerns about the drug’s cardiac risks. © 2024 The New York Times Company

Keyword: Drug Abuse
Link ID: 29179 - Posted: 03.05.2024

By Katherine Ellison Jonel Dershem first noticed problems with her memory in 2016 after her breast cancer surgery. She was only 50 and at first blamed the lapses on chemotherapy, and then on her busy, stressful life. So did her husband and friends — and doctor. “I kept blowing it off,” said Dershem, an obstetrician from Voorhees, N.J., whose challenges began with little things like leaving a faucet running and progressed to trouble finishing routine tasks. “I was our family’s primary breadwinner. I didn’t want there to be any serious problems.” In December 2022, nearly seven years after her memory loss began, Dershem was diagnosed with mild cognitive impairment (MCI). Her delayed diagnosis wasn’t unusual, but experts say that needs to change. More than occasional forgetfulness, MCI causes problems that disrupt daily life but don’t make it impossible to function, said Ronald Petersen, director of the Mayo Clinic Alzheimer’s Disease Research Center and the Mayo Clinic Study of Aging. It is often but not always a precursor to dementia, he added. “It’s a subtle condition,” said Petersen, who in 1999 led the first study differentiating patients with MCI from healthy subjects and those with dementia. If you miss a golf date once, no worries, he said, but if “that happened a couple of times last week and people in your family are starting to worry about you — well, that may be MCI.” “With MCI, people can still drive, pay their bills and do their taxes — they just do so less efficiently,” Petersen said. A 2022 study in the journal Alzheimer’s & Dementia projected that 14.4 million people in the United States would have MCI in 2025, and 19.3 million in 2050. An American Academy of Neurology subcommittee estimated that about 1 in 10 people ages 70 to 74 had MCI, and 1 in 4 ages 80 to 84 in 2018.

Keyword: Alzheimers; Learning & Memory
Link ID: 29178 - Posted: 03.05.2024

By Paula Span Determining whether someone has Alzheimer’s disease usually requires an extended diagnostic process. A doctor takes a patient’s medical history, discusses symptoms, administers verbal and visual cognitive tests. The patient may undergo a PET scan, an M.R.I. or a spinal tap — tests that detect the presence of two proteins in the brain, amyloid plaques and tau tangles, both associated with Alzheimer’s. All of that could change dramatically if new criteria proposed by an Alzheimer’s Association working group are widely adopted. Its final recommendations, expected later this year, will accelerate a shift that is already underway: from defining the disease by symptoms and behavior to defining it purely biologically — with biomarkers, substances in the body that indicate disease. The draft guidelines, Revised Criteria for Diagnosis and Staging of Alzheimer’s Disease, call for a simpler approach. That could mean a blood test to indicate the presence of amyloid. Such tests are already available in some clinics and doctors’ offices. “Someone who has biomarker evidence of amyloid in the brain has the disease, whether they’re symptomatic or not,” said Dr. Clifford R. Jack Jr., the chair of the working group and an Alzheimer’s researcher at the Mayo Clinic. “The pathology exists for years before symptom onset,” he added. “That’s the science. It’s irrefutable.” He and his colleagues on the panel do not recommend testing people who have no symptoms of cognitive decline. But skeptics predict that’s likely to happen nonetheless. If so, a sizable proportion would test positive for amyloid and would therefore be diagnosed with Alzheimer’s. A 2015 Dutch study estimated that more than 10 percent of cognitively normal 50-year-olds would test positive, as would almost 16 percent of 60-year-olds and 23 percent of 70-year-olds. Most of those individuals would never develop dementia. © 2024 The New York Times Company

Keyword: Alzheimers
Link ID: 29177 - Posted: 03.05.2024

By Meghan Bartels No matter how much trouble your pet gets into when they’re awake, few sights are as peaceful as a dog curled up in their bed or a cat stretched out in the sun, snoring away. But their experience of sleep can feel impenetrable. What fills the dreams of a dog or cat? That’s a tricky question to answer. Snowball isn’t keeping a dream journal, and there’s no technology yet that can translate the brain activity of even a sleeping human into a secondhand experience of their dream world, much less a sleeping animal. “No one has done research on the content of animals’ dreams,” says Deirdre Barrett, a dream researcher at Harvard University and author of the book The Committee of Sleep. But Rover’s dreamscape isn’t entirely impenetrable, at least to educated guesses. First of all, Barrett says, only your furrier friends appear to dream. Fish, for example, don’t seem to display rapid eye movement (REM), the phase of sleep during which dreams are most common in humans. “I think it’s a really good guess that they don’t have dreams in the sense of anything like the cognitive activity that we call dreams,” she says. Whether birds experience REM sleep is less clear, Barrett says. And some marine mammals always keep one side of their brain awake even while the other sleeps, with no or very strange REM sleep involved. That means seals and dolphins likely don’t dream in anything like the way humans do. But the mammals we keep as pets are solidly REM sleepers. “I think it’s a very safe, strong guess that they are having some kind of cognitive brain activity that is as much like our dreams as their waking perceptions are like ours,” she says. That doesn’t mean that cats and dogs experience humanlike dreams. “It would be a mistake to assume that other animals dream in the same way that we do, just in their nonhuman minds and bodies,” says David Peña-Guzmán, a philosopher at San Francisco State University and author of the book When Animals Dream. For example, humans rarely report scents when recounting dreams; however, we should expect dogs to dream in smells, he says, given that olfaction is so central to their waking experience of the world. © 2024 SCIENTIFIC AMERICAN

Keyword: Sleep; Consciousness
Link ID: 29176 - Posted: 03.05.2024

By Clay Risen Mary Bartlett Bunge, who with her husband, Richard, studied how the body responds to spinal cord injuries and continued their work after his death in 1996, ultimately discovering a promising treatment to restore movement to millions of paralyzed patients, died on Feb. 17, at her home in Coral Gables, Fla. She was 92. The Miami Project to Cure Paralysis, a nonprofit research organization with which Dr. Bunge (pronounced BUN-ghee) was affiliated, announced the death. “She definitely was the top woman in neuroscience, not just in the United States but in the world,” Dr. Barth Green, a co-founder and dean at the Miami Project, said in a phone interview. Dr. Bunge’s focus for much of her career was on myelin, a mix of proteins and fatty acids that coats nerve fibers, protecting them and boosting the speed at which they conduct signals. Early in her career, she and her husband, whom she met as a graduate student at the University of Wisconsin in the 1950s, used new electron microscopes to describe the way that myelin developed around nerve fibers, and how, after because of injury or illness, it receded, in a process called demyelination. Treating spinal-cord injuries is one of the most frustrating corners of medical research. Thousands of people are left partially or fully paralyzed after automobile accidents, falls, sports injuries and gun violence each year. Unlike other parts of the body, the spinal cord is stubbornly difficult to rehabilitate. Through their research, the Bunges concluded that demyelination was one reason spinal-cord injuries have been so difficult for the body to repair — an insight that in turn opened doors to the possibility of reversing it through treatments. © 2024 The New York Times Company

Keyword: Glia; Regeneration
Link ID: 29175 - Posted: 03.05.2024

By McKenzie Prillaman It’s no secret that global obesity rates have been rising over the past few decades. But a new analysis quantifies the upsurge. More than 1 billion people worldwide were living with obesity as of 2022, researchers report February 29 in the Lancet. That’s about one-eighth of the global population (SN: 11/15/22). For comparison, nearly 800 million people had obesity in 2016, according to the World Health Organization, or WHO. Obesity is “defined by the presence of excess body fat that impairs health,” says obesity expert Arya Sharma of the University of Alberta in Edmonton, Canada, who was not involved in the study. The chronic disease can raise the risk for conditions like heart disease and type 2 diabetes, vulnerability to diseases like COVID-19, and can also limit mobility and negatively affect mental health (SN: 4/22/20). Global health researcher Majid Ezzati and colleagues examined more than 3,600 population-based studies published over the last several decades encompassing 222 million participants across nearly 200 countries and territories. The researchers divided each participant’s reported weight by their height squared to find their body mass index, or BMI. Analyzing the trends suggested that in 2022, almost 900 million adults worldwide had a BMI of 30 or above, classifying them as having obesity. In children and adolescents ages 5 to 19, nearly 160 million were estimated to have the chronic disease, defined as BMI above a certain point on the WHO’s growth reference curves, which account for age and sex. From 1990 to 2022, the prevalence of obesity roughly doubled in women, tripled in men and quadrupled in children and adolescents. At the same time, global rates of those who were underweight fell. “We shouldn’t be thinking about [underweight and obesity] as two separate things, because the transition from one to the other has been very rapid,” says Ezzati, of Imperial College London. © Society for Science & the Public 2000–202

Keyword: Obesity
Link ID: 29174 - Posted: 03.02.2024

Philip Hoare Whales are extraordinarily sensuous creatures. Those blubbery bodies are highly sensitive, and sensitised. At social meetings, pods of sperm, humpback and right whales will roll around one another’s bodies for hours at a time. I’ve seen a group of right whales engaged in foreplay and penetration lasting an entire morning. I have also watched a male-female couple so blissfully conjoined that they appeared unbothered by our little fishing boat as they passed underneath it. And in what may sound like a career of cetacean voyeurism, I have also been caught up in a fast-moving superpod of dusky dolphins continually penetrating each other at speed, regardless of the gender of their partner. That’s why this week’s report of the first scientifically documented male-to-male sexual interactions between two humpback whales off the coast of Hawaii is not surprising. The remarkable image of a two-metre whale penis entering another male “leaves little room for discussion that there is a sexual component to such behaviour”, as one whale scientist, Jeroen Hoekendijk at the Wageningen Marine Research institute in the Netherlands, notes drily. In fact, one of the whales was ailing and there has been speculation that the encounter may not have been consensual or that the healthy whale was actually giving comfort to the other. Whatever the truth, such “flagrant” acts also expose many of our human presumptions about sexuality, gender and identity. Off the north-west Pacific coast of the US, male orcas often leave family pods to rub their erections against each other’s bellies. But females have also reportedly been seen engaging in sexual contact with one another, too. © 2024 Guardian News & Media Limited

Keyword: Sexual Behavior
Link ID: 29173 - Posted: 03.02.2024

By Erica Goode Authors don’t get to choose what’s going on in the world when their books are published. More than a few luckless writers ended up with a publication date of Sept. 11, 2001, or perhaps Nov. 8, 2016, the day Donald Trump was elected. But Charan Ranganath, the author of “Why We Remember: Unlocking Memory’s Power to Hold on to What Matters,”was more fortunate. His book went on sale last month, not long after the Department of Justice released a report describing President Joe Biden as an “elderly man with a poor memory” who, in interviews, was “struggling to remember events,” including the year that his son Beau died. BOOK REVIEW — “Why We Remember: Unlocking Memory’s Power to Hold on to What Matters,” by Charan Ranganath (Doubleday, 304 pages). The special counsel’s report immediately became a topic of intense discussion — disputed by the White House, seized on by many Republicans, analyzed by media commentators, and satirized by late-night television hosts. But for Ranganath, a psychologist and neuroscientist at the University of California, Davis, who for decades has been studying the workings of memory, the report’s release was a stroke of luck. His book, which dispels many widespread but wrongheaded assumptions about memory — including some to which that special counsel Robert K. Hur appears to subscribe — could easily have been written as a corrective response. If Ranganath has a central message, it is that we are far too concerned about forgetting. Memory does not work like a recording device, preserving everything we have heard, seen, said, and done. Not remembering names or exact dates; having no recollection of the details of a conversation; being unable to recall where you left your glasses or your keys; or watching movies you saw in the past as if you are seeing them for the first time — these are not the symptoms of a failing brain.

Keyword: Learning & Memory
Link ID: 29172 - Posted: 03.02.2024

By Pam Belluck Long Covid may lead to measurable cognitive decline, especially in the ability to remember, reason and plan, a large new study suggests. Cognitive testing of nearly 113,000 people in England found that those with persistent post-Covid symptoms scored the equivalent of 6 I.Q. points lower than people who had never been infected with the coronavirus, according to the study, published Wednesday in The New England Journal of Medicine. People who had been infected and no longer had symptoms also scored slightly lower than people who had never been infected, by the equivalent of 3 I.Q. points, even if they were ill for only a short time. The differences in cognitive scores were relatively small, and neurological experts cautioned that the results did not imply that being infected with the coronavirus or developing long Covid caused profound deficits in thinking and function. But the experts said the findings are important because they provide numerical evidence for the brain fog, focus and memory problems that afflict many people with long Covid. “These emerging and coalescing findings are generally highlighting that yes, there is cognitive impairment in long Covid survivors — it’s a real phenomenon,” said James C. Jackson, a neuropsychologist at Vanderbilt Medical Center, who was not involved in the study. He and other experts noted that the results were consistent with smaller studies that have found signals of cognitive impairment. The new study also found reasons for optimism, suggesting that if people’s long Covid symptoms ease, the related cognitive impairment might, too: People who had experienced long Covid symptoms for months and eventually recovered had cognitive scores similar to those who had experienced a quick recovery, the study found. © 2024 The New York Times Company

Keyword: Attention; Learning & Memory
Link ID: 29171 - Posted: 02.29.2024

By Erin Garcia de Jesús A genetic parasite may have robbed humans and other apes of their tails. Around 25 million years ago, this parasite, a small stretch of repetitive DNA called an Alu element, ended up in a gene important for tail development, researchers report in the Feb. 29 Nature. The single insertion altered the gene Tbxt in a way that seems to have sparked one of the defining differences between monkeys and apes: Monkeys have tails, apes don’t. “It was like lightning struck once,” says Jef Boeke, a geneticist at New York University Langone Health, and ape behinds ultimately became bare. The genetic tweak may also give insight into why some babies are born with spinal cord defects such as spina bifida, when the tube that holds the cord doesn’t close all the way (SN: 12/6/16). Alu elements are part of a group of genetic parasites known as transposons or jumping genes that can hop across genetic instruction books, inserting themselves into their hosts’ DNA (SN: 5/16/17). Sometimes, when the gene slips itself into a piece of DNA that is passed down to offspring, these insertions become permanent parts of our genetic code. Transposons, including more than 1 million Alu elements, are found throughout our genome, says geneticist and systems biologist Bo Xia of the Broad Institute in Cambridge, Mass. Researchers once thought of transposons as genetic garbage, but some have central roles in evolution. Without transposons, the placenta, immune system and insulation around nerve fibers may not exist (SN: 2/16/24). And humans might still have tails. To find out how apes lost their tails, Xia, then at NYU Langone Health, Boeke and colleagues analyzed 140 genes involved in vertebrate tail development. © Society for Science & the Public 2000–2024.

Keyword: Evolution; Epigenetics
Link ID: 29170 - Posted: 02.29.2024

By Anthony Ham What is the meaning of a cat’s meow that grows louder and louder? Or your pet’s sudden flip from softly purring as you stroke its back to biting your hand? It turns out these misunderstood moments with your cat may be more common than not. A new study by French researchers, published last month in the journal Applied Animal Behaviour Science, found that people were significantly worse at reading the cues of an unhappy cat (nearly one third got it wrong) than those of a contented cat (closer to 10 percent). The study also suggested that a cat’s meows and other vocalizations are greatly misinterpreted and that people should consider both vocal and visual cues to try to determine what’s going on with their pets. The researchers drew these findings from the answers of 630 online participants; respondents were volunteers recruited through advertisements on social media. Each watched 24 videos of differing cat behaviors. One third depicted only vocal communication, another third just visual cues, and the remainder involved both. “Some studies have focused on how humans understand cat vocalizations,” said Charlotte de Mouzon, lead author of the study and a cat behavior expert at the Université Paris Nanterre. “Other studies studied how people understand cats’ visual cues. But studying both has never before been studied in human-cat communication.” Cats display a wide range of visual signals: tails swishing side to side, or raised high in the air; rubbing and curling around our legs; crouching; flattening ears or widening eyes. Their vocals can range from seductive to threatening: meowing, purring, growling, hissing and caterwauling. At last count, kittens were known to use nine different forms of vocalization, while adult cats uttered 16. That we could better understand what a cat wants by using visual and vocal cues may seem obvious. But we know far less than we think we do. © 2024 The New York Times Compan

Keyword: Animal Communication; Evolution
Link ID: 29169 - Posted: 02.29.2024

By Benjamin Ryan People who frequently smoke marijuana have a higher risk of heart attack and stroke, according to a study published on Wednesday. The article, published in The Journal of the American Heart Association, is an analysis of responses to the U.S. government’s annual survey on behavioral risk from 2016 to 2020. The respondents answered health questions, including reporting their own health problems related to heart disease. About 4 percent of the respondents reported daily marijuana use, which the researchers suggested raised the chance of a heart attack by 25 percent and of a stroke by 42 percent. Among those who never smoked tobacco, daily use was tied to a 49 percent higher risk of heart attack and a more than doubled risk of stroke, the study indicated. About three-quarters of the respondents said that smoking was their main method of using weed. The other quarter consumed it by vaping, through edibles or drinking it. “Cannabis smoke releases the same toxins and particulate matter that tobacco does,” said the study’s first author, Abra M. Jeffers, a data analyst at Massachusetts General Hospital in Boston. She conducted the analysis during her post-doctoral fellowship at the University of California, San Francisco. The study is merely observational in its review of survey responses; it does not provide conclusive evidence that regular marijuana use causes heart disease. Even so, researchers and experts said they were concerned about its implications, especially as cannabis use has increased in recent years. Thirty-eight states have legalized medical use of marijuana, and 24 have begun allowing recreational use. © 2024 The New York Times Company

Keyword: Drug Abuse
Link ID: 29168 - Posted: 02.29.2024

By Saima Sidik Eye diseases long thought to be purely genetic might be caused in part by bacteria that escape the gut and travel to the retina, research suggests1. Eyes are typically thought to be protected by a layer of tissue that bacteria can’t penetrate, so the results are “unexpected”, says Martin Kriegel, a microbiome researcher at the University of Münster in Germany, who was not involved in the work. “It’s going to be a big paradigm shift,” he adds. The study was published on 26 February in Cell. Inherited retinal diseases, such as retinitis pigmentosa, affect about 5.5 million people worldwide. Mutations in the gene Crumbs homolog 1 (CRB1) are a leading cause of these conditions, some of which cause blindness. Previous work2 suggested that bacteria are not as rare in the eyes as ophthalmologists had previously thought, leading the study’s authors to wonder whether bacteria cause retinal disease, says co-author Richard Lee, an ophthalmologist then at the University College London. CRB1 mutations weaken linkages between cells lining the colon in addition to their long-observed role in weakening the protective barrier around the eye, Lee and his colleagues found. This motivated study co-author Lai Wei, an ophthalmologist at Guangzhou Medical University in China, to produce Crb1-mutant mice with depleted levels of bacteria. These mice did not show evidence of distorted cell layers in the retina, unlike their counterparts with typical gut flora. Furthermore, treating the mutant mice with antibiotics reduced the damage to their eyes, suggesting that people with CRB1 mutations could benefit from antibiotics or from anti-inflammatory drugs that reduce the effects of bacteria. “If this is a novel mechanism that is treatable, it will transform the lives of many families,” Lee says. © 2024 Springer Nature Limited

Keyword: Vision
Link ID: 29167 - Posted: 02.27.2024

Terry Gross When cognitive neuroscientist Charan Ranganath meets someone for the first time, he's often asked, "Why am I so forgetful?" But Ranganath says he's more interested in what we remember, rather than the things we forget. "We're not designed to carry tons and tons of junk with us. I don't know that anyone would want to remember every temporary password that they've ever had," he says. "I think what [the human brain is] designed for is to carry what we need and to deploy it rapidly when we need it." Ranganath directs the Dynamic Memory Lab at the University of California, Davis, where he's a professor of psychology and neuroscience. In the new book, Why We Remember, he writes about the fundamental mechanisms of memory — and why memories often change over time. Sponsor Message Ranganath recently wrote an op-ed for The New York Times in which he reflected on President Biden's memory gaffes — and the role that memory plays in the current election cycle. "I'm just not in the position to say anything about the specifics of [either Biden or Trump's] memory problems," he says. "This is really more of an issue of people understanding what happens with aging. And, one of the nice things about writing this editorial is I got a lot of feedback from people who felt personally relieved by this because they're worried about their own memories." I think it would be a good idea to have a comprehensive physical and mental health evaluation that's fairly transparent. We certainly have transparency or seek transparency about other things like a candidate's finances, for instance. And obviously health is a very important factor. And I think at the end of the day, we'll still be in a position of saying, "OK, what's enough? What's the line between healthy and unhealthy?" But I think it's important to do because yes, as we get older we do have memory problems. ... © 2024 npr

Keyword: Learning & Memory; Development of the Brain
Link ID: 29166 - Posted: 02.27.2024

NIH-funded study shows prenatal mental health support is effective for women living in low-resource settings. Results from a large clinical trial funded by the National Institutes of Health show that an intervention for anxiety provided to pregnant women living in Pakistan significantly reduced the likelihood of the women developing moderate-to-severe anxiety, depression, or both six weeks after birth. The unique intervention was administered by non-specialized providers who had the equivalent of a bachelor’s degree in psychology—but no clinical experience. The results suggest this intervention could be an effective way to prevent the development of postpartum mental health challenges in women living in low-resource settings. “In low resource settings, it can be challenging for women to access mental health care due to a global shortage of trained mental health specialists,” said Joshua A. Gordon, M.D., Ph.D., Director of the National Institute of Mental Health, part of NIH. “This study shows that non-specialists could help to fill this gap, providing care to more women during this critical period." Led by Pamela J. Surkan, Ph.D., Sc.D.(link is external), of Johns Hopkins Bloomberg School of Public Health, Baltimore, the study was conducted in the Punjab Province of Pakistan between April 2019 and January 2022. Pregnant women with symptoms of at least mild anxiety were randomly assigned to receive either routine pregnancy care or a cognitive behavioral therapy (CBT)-based intervention called Happy Mother-Healthy Baby. The researchers assessed the participants (380 women in the CBT group and 375 women in the routine care group) for anxiety and depression six weeks after the birth of their child.

Keyword: Depression; Sexual Behavior
Link ID: 29165 - Posted: 02.27.2024

Ayana Archie The monthly rate of antidepressants being dispensed to young people increased about 64% more quickly during the coronavirus pandemic, according to a study published Monday in the journal Pediatrics. Researchers used the IQVIA Longitudinal Prescription Database to examine a sample of about 221 million prescriptions written for millions of Americans between the ages 12 to 25, and from 2016 to 2022. Researchers additionally separated the data into before and after March 2020, when the pandemic started. The increase was prominent among young women and girls. The monthly rate increased about 130% faster among 12- to 17-year-old girls, and about 57% faster among young women between the ages of 18 and 25. The study hypothesizes this jump could be due to high rates of depression or anxiety, better access to health care, due to things such as telehealth, or people's reliance on prescriptions because of long waitlists for therapy during the pandemic. The dataset includes prescriptions dispensed from "retail, mail-order, and long-term care pharmacies in the United States," the study says, not exclusive health care systems, such as Kaiser Permanente. Conversely, during the pandemic, the monthly antidepressant dispensing rate decreased for boys between the ages of 12 to 17 and did not change for young men between 18 and 25. Though, data shows more male adolescents were sent to the emergency room for suspected suicide attempts in early 2021, compared to early 2019. Between 2019 and 2021, male high school students also reported constantly feeling sad or hopeless more often, according to the researchers. © 2024 npr

Keyword: Depression
Link ID: 29164 - Posted: 02.27.2024