Chapter 5. The Sensorimotor System
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By Pam Belluck When Shawn Connolly was diagnosed with Parkinson’s disease nine years ago, he was a 39-year-old daredevil on a skateboard, flipping and leaping from walls, benches and dumpsters through the streets of San Francisco. He appeared in videos and magazines, and had sponsorships from skateboard makers and shops. But gradually, he began to notice that “things weren’t really working right” with his body. He found that his right hand was cupping, and he began cradling his arm to hold it in place. His balance and alignment started to seem off. Over time, he developed a common Parkinson’s pattern, fluctuating between periods of rapid involuntary movements like “I’ve got ants in my pants” and periods of calcified slowness when, he said, “I could barely move.” A couple of years ago, Mr. Connolly volunteered for an experiment that summoned his daring and determination in a different way. He became a participant in a study exploring an innovative approach to deep brain stimulation. In the study, which was published Monday in the journal Nature Medicine, researchers transformed deep brain stimulation — an established treatment for Parkinson’s — into a personalized therapy that tailored the amount of electrical stimulation to each patient’s individual symptoms. The researchers found that for Mr. Connolly and the three other participants, the individualized approach, called adaptive deep brain stimulation, cut in half the time they experienced their most bothersome symptom. Mr. Connolly, now 48 and still skateboarding as much as his symptoms allow, said he noticed the difference “instantly.” He said the personalization gave him longer stretches of “feeling good and having that get-up-and-go.” © 2024 The New York Times Company
Keyword: Parkinsons
Link ID: 29447 - Posted: 08.21.2024
By Marla Broadfoot When doctors ask Sara Gehrig to describe her pain, she often says it is indescribable. Stabbing, burning, aching—those words frequently fail to depict sensations that have persisted for so long they are now a part of her, like her bones and skin. “My pain is like an extra limb that comes along with me every day.” Gehrig, a former yoga instructor and personal trainer who lives in Wisconsin, is 44 years old. At the age of 17 she discovered she had spinal stenosis, a narrowing of the spinal cord that puts pressure on the nerves there. She experienced bursts of excruciating pain in her back and buttocks and running down her legs. That pain has spread over the years, despite attempts to fend it off with physical therapy, anti-inflammatory injections and multiple surgeries. Over-the-counter medications such as ibuprofen (Advil) provide little relief. And she is allergic to the most potent painkillers—prescription opioids—which can induce violent vomiting. Today her agony typically hovers at a 7 out of 10 on the standard numerical scale used to rate pain, where 0 is no pain and 10 is the most severe imaginable. Occasionally her pain flares to a 9 or 10. At one point, before her doctor convinced her to take antidepressants, Gehrig struggled with thoughts of suicide. “For many with chronic pain, it’s always in their back pocket,” she says. “It’s not that we want to die. We want the pain to go away.” Gehrig says she would be willing to try another type of painkiller, but only if she knew it was safe. She keeps up with the latest research, so she was interested to hear earlier this year that Vertex Pharmaceuticals was testing a new drug that works differently than opioids and other pain medications. That drug, a pill called VX-548, blocks pain signals before they can reach the brain. It gums up sodium channels in peripheral nerve cells, and obstructed channels make it hard for those cells to transmit pain sensations. Because the drug acts only on the peripheral nerves, it does not carry the potential for addiction associated with opioids—oxycodone (OxyContin) and similar drugs exert their effects on the brain and spinal cord and thus can trigger the brain’s reward centers and an addiction cycle.
Keyword: Pain & Touch; Drug Abuse
Link ID: 29445 - Posted: 08.21.2024
Julia Kollewe Oran Knowlson, a British teenager with a severe type of epilepsy called Lennox-Gastaut syndrome, became the first person in the world to trial a new brain implant last October, with phenomenal results – his daytime seizures were reduced by 80%. “It’s had a huge impact on his life and has prevented him from having the falls and injuring himself that he was having before,” says Martin Tisdall, a consultant paediatric neurosurgeon at Great Ormond Street Hospital (Gosh) in London, who implanted the device. “His mother was talking about how he’s had such a improvement in his quality of life, but also in his cognition: he’s more alert and more engaged.” Oran’s neurostimulator sits under the skull and sends constant electrical signals deep into his brain with the aim of blocking abnormal impulses that trigger seizures. The implant, called a Picostim and about the size of a mobile phone battery, is recharged via headphones and operates differently between day and night. The video player is currently playing an ad. You can skip the ad in 5 sec with a mouse or keyboard “The device has the ability to record from the brain, to measure brain activity, and that allows us to think about ways in which we could use that information to improve the efficacy of the stimulation that the kids are getting,” says Tisdall. “What we really want to do is to deliver this treatment on the NHS.” As part of a pilot, three more children with Lennox-Gastaut syndrome will be fitted with the implant in the coming weeks, followed by a full trial with 22 children early next year. If this goes well, the academic sponsors – Gosh and University College London – will apply for regulatory approval. Tim Denison – a professor of engineering science at Oxford University and co-founder and chief engineer of London-based Amber Therapeutics, which developed the implant with the university – hopes the device will be available on the NHS in four to five years’ time, and around the world. © 2024 Guardian News & Media Limite
Keyword: Robotics; Epilepsy
Link ID: 29442 - Posted: 08.19.2024
By Sara Talpos Nervous system disorders are among the leading causes of death and disability globally. Conditions such as paralysis and aphasia, which affects the ability to understand and produce language, can be devastating to patients and families. Significant investment has been put toward brain research, including the development of new technologies to treat some conditions, said Saskia Hendriks, a bioethicist at the U.S. National Institutes of Health. These technologies may very well improve lives, but they also raise a host of ethical issues. That’s in part because of the unique nature of the brain, said Hendriks. It’s “the seat of many functions that we think are really important to ourselves, like consciousness, thoughts, memories, emotions, perceptions, actions, perhaps identity.” Saskia Hendriks, a bioethicist at the U.S. National Institutes of Health, recently co-authored an essay on the emerging ethical questions in highly innovative brain research. In a June essay in The New England Journal of Medicine, Hendriks and a co-author, Christine Grady, outlined some of the thorny ethical questions related to brain research: What is the best way to protect the long-term interests of people who receive brain implants as part of a clinical trial? As technology gets better at decoding thoughts, how can researchers guard against violations of mental privacy? And what best way to prepare for the far-off possibility that consciousness may one day arise from work derived from human stem cells? Hendriks spoke about the essay in a Zoom interview. Our conversation has been edited for length and clarity.
Keyword: Robotics
Link ID: 29441 - Posted: 08.19.2024
By Paula Span Mary Peart, 67, a retired nurse in Manchester-by-the-Sea, Mass., began taking gabapentin a year and a half ago to reduce the pain and fatigue of fibromyalgia. The drug helps her climb stairs, walk her dog and take art lessons, she said. With it, “I have a life,” she said. “If I forget to take a dose, my pain comes right back.” Jane Dausch has a neurological condition called transverse myelitis and uses gabapentin as needed when her legs and feet ache. “It seems to be effective at calming down nerve pain,” said Ms. Dausch, 67, a retired physical therapist in North Kingstown, R.I. Amy Thomas, who owns three bookstores in the San Francisco Bay Area, takes gabapentin for rheumatoid arthritis. Along with yoga and physical therapy, “it’s probably contributing to it being easier for me to move around,” Ms. Thomas, 67, said. All three are taking the non-opioid pain drug for off-label uses. The only conditions for which gabapentin has been approved for adult use by the Food and Drug Administration are epileptic seizures, in 1993, and postherpetic neuralgia, the nerve pain that can linger after a bout of shingles, in 2002. But that has not stopped patients and health care providers from turning to gabapentin (whose brand names include Neurontin) for a startling array of other conditions, including sciatica, neuropathy from diabetes, lower back pain and post-surgery pain. Also: Agitation from dementia. Insomnia. Migraines. Itching. Bipolar disorder. Alcohol dependence. Evidence of effectiveness for these conditions is all over the map. The drug appears to provide relief for some patients with diabetic neuropathy but not with some other kinds of neuropathic pain. Several small studies indicate that gabapentin can reduce the itching associated with kidney failure. But the data for its effectiveness against low back pain or a number of psychiatric disorders are limited and show no meaningful impact. “It’s crazy how many indications it’s used for,” said Dr. Michael Steinman, a geriatrician at the University of California, San Francisco, and a co-director of the U.S. Deprescribing Research Network. “It’s become a we-don’t-know-what-else-to-do drug.” © 2024 The New York Times Company
Keyword: Pain & Touch; Drug Abuse
Link ID: 29438 - Posted: 08.19.2024
By Elena Kazamia It was a profound moment of connection. Carlos Casas could feel the elephant probing him, touching him with sound. The grunts emanating from the large male were of a frequency too low to hear, but Casas felt an agitation on his skin and deep inside his chest. “I was being scanned,” he says. At the time of the encounter, Casas was filming a project in Sri Lanka, and was holding a camera. But his interactions with the elephant gave the Catalonian filmmaker and installation artist an idea: What if instead of relying on images alone, he could use sound to create a physical connection between an audience of people and the subjects that fascinate him most, the animals with which we share life on this planet? Bestiari, his audio-visual project, now on display inside a former shipping warehouse at the Venice Biennale, weaves an immersive landscape for visitors. (You can explore some of the project, which was curated by Filipa Ramos, at the Instagram page for the installation.) Audio of the sounds the animals make is accompanied by video collected from remote camera traps set across national parks of Catalonia and Kenya, together with abstract film meant to capture the world as the animals see it, based on a combination of scientific research and artistic license. A series of texts serve as field guides to each animal featured in the installation. Entering the dark warehouse where Bestiari is housed, you are invited to lie on the floor, as if to fall asleep, before communing with seven different species: bees, donkeys, parakeets, snakes, bats, dolphins, and elephants. Each of the chosen species is represented by a speaker, customized to deliver the desired acoustics. Casas calls the speakers, “Trojan horses of meaning and communication.” The pitches and volumes were curated to be authentic to the original animal but perceptible by humans. For example, the echolocation chirps of bats have been slowed down to showcase the tonal progression of the sound. © 2024 NautilusNext Inc.,
Keyword: Hearing; Evolution
Link ID: 29421 - Posted: 08.03.2024
By Hannah Richter Humans aren’t the only animals that lose hearing as they grow older. Almost every mammal studied struggles to pick up some sounds as they age. Some veterinarians even fit dogs for tiny hearing aids. But at least one species of bat appears to be an exception. Reporting this month on the preprint server bioRxiv, scientists have discovered that big brown bats (Eptesicus fuscus) don’t hear any worse as they grow older, possibly because their ability to echolocate is so critical to their survival. “Hearing is kind of their superpower,” says Mirjam Knörnschild, a behavioral ecologist at the Museum of Natural History Berlin who was not involved with the work. The research, she and others say, could lead to new ways to understand—and possibly treat—hearing loss in humans. Bats actually have two superpowers. Not only can most of them echolocate—bouncing sound off objects to hunt and navigate—they also tend to be remarkably long-lived for their size. Most small mammals are short-lived, but compared with mice of similar stature, the big brown bat lives up to five times as long, sometimes topping out at 19 years old. That makes the species a fascinating target for studies of aging, says Grace Capshaw, a postdoctoral researcher at Johns Hopkins University. The bat auditory system is fundamentally the same as that of every other mammal, she says, so “bats can be a really powerful model for comparing how hearing works.” To test whether big brown bats lose their hearing over time, Capshaw and colleagues divided 23 wild-caught bats into groups of young and old, making 6 years—the mean age of the species—the dividing line. The researchers determined the bats’ ages using a precise genetic method that involves comparing each animal’s DNA with the DNA of bats with known ages. They then sedated the animals to conduct a hearing examination similar to those done on human infants.
Keyword: Hearing
Link ID: 29411 - Posted: 07.31.2024
By Miryam Naddaf About one-third of people who suffer from migraines experience a phenomenon known as aura before the headache.Credit: Tunatura/Getty For one billion people worldwide, the symptoms can be debilitating: throbbing head pain, nausea, blurred vision and fatigue that can last for days. But how brain activity triggers these severest of headaches — migraines — has long puzzled scientists. A study1 in mice, published in Science on 4 July, now offers clues about the neurological events that spark migraines. It suggests that a brief brain ‘blackout’ — when neuronal activity shuts down — temporarily changes the content of the cerebrospinal fluid, the clear liquid that surrounds the brain and spinal cord. This altered fluid, researchers suggest, travels through a previously unknown gap in anatomy to nerves in the skull where it activates pain and inflammatory receptors, causing headaches. “This work is a shift in how we think the headaches originate,” says Gregory Dussor, a neuroscientist at the University of Texas at Dallas in Richardson. “A headache might just be a general warning sign for lots of things happening inside the brain that aren’t normal.” “Migraine is actually protective in that way. The pain is protective because it’s telling the person to rest and recover and sleep,” says study co-author Maiken Nedergaard, a neuroscientist at the University of Copenhagen. The brain itself has no pain receptors; the sensation of headaches comes from areas outside the brain that are in the peripheral nervous system. But how the brain, which is not directly linked to the peripheral nervous system, triggers nerves to cause headaches is poorly understood, making them difficult to treat. © 2024 Springer Nature Limited
Keyword: Pain & Touch
Link ID: 29388 - Posted: 07.11.2024
Tijl Grootswagers Genevieve L Quek Manuel Varlet You are standing in the cereal aisle, weighing up whether to buy a healthy bran or a sugary chocolate-flavoured alternative. Your hand hovers momentarily before you make the final grab. But did you know that during those last few seconds, while you’re reaching out, your brain is still evaluating the pros and cons – influenced by everything from your last meal, the health star rating, the catchy jingle in the ad, and the colours of the letters on the box? Our recently published research shows our brains do not just think first and then act. Even while you are reaching for a product on a supermarket shelf, your brain is still evaluating whether you are making the right choice. Read news coverage based on evidence, not tweets Further, we found measuring hand movements offers an accurate window into the brain’s ongoing evaluation of the decision – you don’t have to hook people up to expensive brain scanners. What does this say about our decision-making? And what does it mean for consumers and the people marketing to them? There has been debate within neuroscience on whether a person’s movements to enact a decision can be modified once the brain’s “motor plan” has been made. Our research revealed not only that movements can be changed after a decision – “in flight” – but also the changes matched incoming information from a person’s senses. To study how our decisions unfold over time, we tracked people’s hand movements as they reached for different options shown in pictures – for example, in response to the question “is this picture a face or an object?” Put simply, reaching movements are shaped by ongoing thinking and decision-making. © 2010–2024, The Conversation US, Inc.
Keyword: Consciousness
Link ID: 29387 - Posted: 07.11.2024
By Rodrigo Pérez Ortega It starts with blind spots, flashing lights, and blurry vision—a warning of what’s to come. About an hour later, the dreadful headache kicks in. This pairing, a shining visual experience called an aura and then a headache, happens in about one-third of people who live with migraine. But researchers haven’t been able to figure out exactly how the two are linked at the molecular level. Now, a new study in mice, published today in Science, establishes a direct mechanism: molecules traveling in the fluid that bathes the brain. The finding could lead to new targets for much-needed migraine treatments. “It’s exciting,” says Rami Burstein, a translational neuroscientist at Harvard Medical School who was not involved in the new study. “It takes a very large step into understanding how something that happened in the brain can alter sensation or perception,” he says. It may also explain why the pain of migraine is experienced only in the head, he adds. Migraine, a debilitating neurological disorder, affects about 148 million people worldwide. Recently developed medications can help reduce headaches but are not effective for everyone. Although exact causes remain elusive, research has shown migraines most likely start with a pathological burst of neural activity. During an aura before a migraine, researchers have observed a seizurelike phenomenon called cortical spreading depression (CSD), in which a wave of abnormal neural firing slowly travels throughout the brain’s outer layer, or cortex. But because the brain itself contains no pain-sensing neurons, signals from the brain would have to somehow reach the peripheral nervous system—the nerves that communicate between the body parts and the brain—to cause a headache. In particular, they’d have to get to the two lumps of neurons below the brain called the trigeminal ganglia, which innervate the two sides of our face and head. Scientists knew that pain fibers from the trigeminal ganglion were nested in the meninges—the thin, delicate membranes that envelop and protect the brain.
Keyword: Pain & Touch
Link ID: 29380 - Posted: 07.06.2024
By Miryam Naddaf Researchers have developed a four-dimensional model of spinal-cord injury in mice, which shows how nearly half a million cells in the spinal cord respond over time to injuries of varying severity. The model, known as a cell atlas, could help researchers to resolve outstanding questions and develop new treatments for people with spinal-cord injury (SCI). “If you know what every single cell on the spinal cord is doing in response to injury, you could use that knowledge to develop tailor-made and mechanism-based therapies,” says Mark Anderson, a neurobiologist at the Swiss Federal Institute of Technology in Geneva, Switzerland, who worked on the atlas. “Things don’t need to be a shot in the dark.” Anderson and his colleagues used machine-learning algorithms to build the atlas by mapping data from RNA sequencing and other cell-biology techniques. They described the work in a Nature paper published today1 and have made the entire atlas available through an online platform. The atlas is a valuable resource for testing hypotheses about SCI, says Binhai Zheng, who studies spinal-cord regeneration at the University of California, San Diego. “There are a lot of hidden treasures.” The researchers examined sections of the spinal cord, sampled from 52 injured and uninjured mice at 1, 4, 7, 14, 30 and 60 days after injury. Their analysis involved 18 experimental SCI conditions, including different types of injury and levels of severity. They used RNA-sequencing tools to explore how 482,825 cells responded to injury over time. © 2024 Springer Nature Limited
Keyword: Brain imaging; Brain Injury/Concussion
Link ID: 29368 - Posted: 06.26.2024
By Claire Yuan Men and women experience pain differently, and until now, scientists didn’t know why. New research says it may be in part due to differences in male and female nerve cells. Pain-sensing nerve cells from male and female animal tissues responded differently to the same sensitizing substances, researchers report June 3 in Brain. The results suggest that at the cellular level, pain is produced differently between the sexes. The results might allow researchers “to come up with drugs that would be specific to treat female patients or male patients,” says Katherine Martucci, a neuroscientist who studies chronic pain at Duke University School of Medicine and was not involved in the study. “There’s no debate about it. They’re seeing these differences in the cells.” Some types of chronic and acute pain appear more often in one sex, but it’s unclear why. For instance, about 50 million adults in the United States suffer from chronic pain conditions, many of which are more common in women (SN: 5/22/23). Similar disparities exist for acute conditions. Such differences prompted pain researcher Frank Porreca of the University of Arizona Health Sciences in Tucson and colleagues to study nerve cells called nociceptors, which can act like alarm sensors for the body. The cells’ pain sensors, found in skin, organs and elsewhere in the body, can detect potentially dangerous stimuli and send signals to the brain, which then interprets the information as pain. In some cases, the nerve cells can become more sensitive to outside stimulation, registering even gentle sensations — like a shirt rubbing sunburned skin — as pain. © Society for Science & the Public 2000–2024.
Keyword: Pain & Touch; Sexual Behavior
Link ID: 29366 - Posted: 06.24.2024
By Sara Reardon Specific nerve cells on the penis and clitoris detect vibrations and then become activated, causing sexual behaviours such as erections, a study in mice has revealed1. The findings could lead to new treatments for conditions such as erectile dysfunction, or for restoring sexual function in people with lower-body paralysis. Krause corpuscles — nerve endings in tightly wrapped balls located just under the skin — were first discovered in human genitals more than 150 years ago. The structures are similar to touch-activated corpuscles found on people’s fingers and hands, which respond to vibrations as the skin moves across a textured surface. But there is little research into how the genital corpuscles work and how they are involved in sex, probably because the topic is sometimes considered taboo. “It’s been hard to get people to work on this because some people have a hard time talking about it,” says David Ginty, a sensory neurobiologist at Harvard Medical School in Boston, Massachusetts, who led the team that conducted the latest research. “But I don’t, because the biology is so interesting.” Ginty and other sensory biologists have long wanted to study these mysterious neuron balls. But activating and tracking specific neurons was nearly impossible until advanced molecular techniques emerged in the past 20 years. In a 19 June paper in Nature1, Ginty and his collaborators activated the Krause corpuscles in both male and female mice using various mechanical and electrical stimuli. The neurons fired in response to low-frequency vibrations in the range of 40–80 hertz. Ginty notes that these frequencies are generally used in many sex toys; humans, it seems, realized that this was the best way to stimulate Krause corpuscles before any official experiments were published. © 2024 Springer Nature Limited
Keyword: Sexual Behavior; Pain & Touch
Link ID: 29365 - Posted: 06.24.2024
By Scott Sayare As a boy, Les Milne carried an air of triumph about him, and an air of sorrow. Les was a particularly promising and energetic young man, an all-Scottish swim champion, head boy at his academy in Dundee, a top student bound for medical school. But when he was young, his father died; his mother was institutionalized with a diagnosis of manic depression, and he and his younger brother were effectively left to fend for themselves. His high school girlfriend, Joy, was drawn to him as much by his sadness as his talents, by his yearning for her care. “We were very, very much in love,” Joy, now a flaxen-haired 72-year-old grandmother, told me recently. In a somewhat less conventional way, she also adored the way Les smelled, and this aroma of salt and musk, accented with a suggestion of leather from the carbolic soap he used at the pool, formed for her a lasting sense of who he was. “It was just him,” Joy said, a steadfast marker of his identity, no less distinctive than his face, his voice, his particular quality of mind. Listen to this article, read by Robert Petkoff Joy’s had always been an unusually sensitive nose, the inheritance, she believes, of her maternal line. Her grandmother was a “hyperosmic,” and she encouraged Joy, as a child, to make the most of her abilities, quizzing her on different varieties of rose, teaching her to distinguish the scent of the petals from the scent of the leaves from the scent of the pistils and stamens. Still, her grandmother did not think odor of any kind to be a polite topic of conversation, and however rich and enjoyable and dense with information the olfactory world might be, she urged her granddaughter to keep her experience of it to herself. Les only learned of Joy’s peculiar nose well after their relationship began, on a trip to the Scandinavian far north. Joy would not stop going on about the creamy odor of the tundra, or what she insisted was the aroma of the cold itself. Joy planned to go off to university in Paris or Rome. Faced with the prospect of tending to his mother alone, however, Les begged her to stay in Scotland. He trained as a doctor, she as a nurse; they married during his residency. He was soon the sort of capable young physician one might hope to meet, a practitioner of uncommon enthusiasm, and shortly after his 30th birthday, he was appointed consultant anesthesiologist at Macclesfield District General Hospital, outside Manchester, in England, the first in his graduating class to make consultant. © 2024 The New York Times Company
Keyword: Parkinsons; Chemical Senses (Smell & Taste)
Link ID: 29363 - Posted: 06.15.2024
By Lauren Leffer Noland Arbaugh has a computer chip embedded in his skull and an electrode array in his brain. But Arbaugh, the first user of the Neuralink brain-computer interface, or BCI, says he wouldn’t know the hardware was there if he didn’t remember going through with the surgery. “If I had lost my memory, and I woke up, and you told me there was something implanted in my brain, then I probably wouldn’t believe you,” says the 30-year-old Arizona resident, who has been paralyzed below the middle of his neck since a 2016 swimming accident. “I have no sensation of it—no way of telling it’s there unless someone goes and physically pushes on it.” The Neuralink chip may be physically unobtrusive, but Arbaugh says it’s had a big impact on his life, allowing him to “reconnect with the world.” He underwent robotic surgery in January to receive the N1 Implant, also called “the Link,” in Neuralink’s first approved human trial. BCIs have existed for decades. But because billionaire technologist Elon Musk owns Neuralink, the company has received outsize attention. It’s brought renewed public interest to a technology that could significantly improve the life of those living with quadriplegia, such as Arbaugh, as well as people with other disabilities or neurodegenerative diseases. BCIs record electrical activity in the brain and translate those data into output actions, such as opening and closing a robotic hand or clicking a computer mouse. They vary in their design, level of invasiveness and the resolution of the information they capture. Some detect neurons’ electrical activity with entirely external electroencephalogram (EEG) arrays placed over a subject’s head. Others use electrodes placed on the brain’s surface to track neural activity. Then there are intracortical devices, which use electrodes implanted directly into brain tissue, to get as close as possible to the targeted neurons. Neuralink’s implant falls into this category. © 2024 SCIENTIFIC AMERICAN,
Keyword: Robotics; Movement Disorders
Link ID: 29362 - Posted: 06.15.2024
By Erin Garcia de Jesús Chronic wasting disease has been spreading among deer in the United States, which has raised concerns that the fatal neurological illness might make the leap to people. But a recent study suggests that the disease has a tough path to take to get into humans. The culprit behind chronic wasting disease, or CWD, isn’t a virus or bacterium but a misfolded brain protein called a prion. A new study using miniature, lab-grown organs called organoids supports previous work, showing that CWD prions don’t infect human brain tissue. Brain organoids exposed to high doses of prions from white-tailed deer, mule deer and elk remained infection-free for the duration of the study, or 180 days, researchers report in the June 2024 Emerging Infectious Diseases. However, organoids exposed to human prions that cause a related condition, Creutzfeldt-Jakob disease, quickly became infected. The finding suggests that a substantial species barrier prevents CWD from making the jump from deer to humans. “This was a model that could really help tell us … whether or not it was a real risk,” says Bradley Groveman, a biologist at the National Institutes of Health’s Rocky Mountain Laboratories in Hamilton, Mont. But brain organoids aren’t a perfect mimic of the real thing and may lack features that would make them susceptible to infection. And new prion strains can appear, perhaps including some that might help deer prions lock onto healthy brain proteins in humans. © Society for Science & the Public 2000–2024.
Keyword: Prions
Link ID: 29355 - Posted: 06.11.2024
Leyland Cecco in Toronto A leading federal scientist in Canada has alleged he was barred from investigating a mystery brain illness in the province of New Brunswick and said he fears more than 200 people affected by the condition are experiencing unexplained neurological decline. The allegations, made in leaked emails to a colleague seen by the Guardian, have emerged two years after the eastern province closed its investigation into a possible “cluster” of cases. “All I will say is that my scientific opinion is that there is something real going on in [New Brunswick] that absolutely cannot be explained by the bias or personal agenda of an individual neurologist,” wrote Michael Coulthart, a prominent microbiologist. “A few cases might be best explained by the latter, but there are just too many (now over 200).” New Brunswick health officials warned in 2021 that more than 40 residents were suffering from a possible unknown neurological syndrome, with symptoms similar to those of the degenerative brain disorder Creutzfeldt-Jakob disease. Those symptoms were varied and dramatic: some patients started drooling and others felt as though bugs were crawling on their skin. A year later, however, an independent oversight committee created by the province determined that the group of patients had most likely been misdiagnosed and were suffering from known illnesses such as cancer and dementia. The committee and the New Brunswick government also cast doubt on the work of neurologist Alier Marrero, who was initially referred dozens of cases by baffled doctors in the region, and subsequently identified more cases. The doctor has since become a fierce advocate for patients he feels have been neglected by the province. © 2024 Guardian News & Media Limited
Keyword: Alzheimers; Depression
Link ID: 29342 - Posted: 06.04.2024
By Emily Underwood You’re driving somewhere, eyes on the road, when you start to feel a tingling sensation in your lower abdomen. That extra-large Coke you drank an hour ago has made its way through your kidneys into your bladder. “Time to pull over,” you think, scanning for an exit ramp. To most people, pulling into a highway rest stop is a profoundly mundane experience. But not to neuroscientist Rita Valentino, who has studied how the brain senses, interprets and acts on the bladder’s signals. She’s fascinated by the brain’s ability to take in sensations from the bladder, combine them with signals from outside of the body, like the sights and sounds of the road, then use that information to act — in this scenario, to find a safe, socially appropriate place to pee. “To me, it’s really an example of one of the beautiful things that the brain does,” she says. Scientists used to think that our bladders were ruled by a relatively straightforward reflex — an “on-off” switch between storing urine and letting it go. “Now we realize it’s much more complex than that,” says Valentino, now director of the division of neuroscience and behavior at the National Institute of Drug Abuse. An intricate network of brain regions that contribute to functions like decision-making, social interactions and awareness of our body’s internal state, also called interoception, participates in making the call. In addition to being mind-bogglingly complex, the system is also delicate. Scientists estimate, for example, that more than 1 in 10 adults have overactive bladder syndrome — a common constellation of symptoms that includes urinary urgency (the sensation of needing to pee even when the bladder isn’t full), nocturia (the need for frequent nightly bathroom visits) and incontinence. Although existing treatments can improve symptoms for some, they don’t work for many people, says Martin Michel, a pharmacologist at Johannes Gutenberg University in Mainz, Germany, who researches therapies for bladder disorders. Developing better drugs has proven so challenging that all major pharmaceutical companies have abandoned the effort, he adds.
Keyword: Miscellaneous
Link ID: 29337 - Posted: 06.02.2024
By Matthew Hutson ChatGPT and other AI tools are upending our digital lives, but our AI interactions are about to get physical. Humanoid robots trained with a particular type of AI to sense and react to their world could lend a hand in factories, space stations, nursing homes and beyond. Two recent papers in Science Robotics highlight how that type of AI — called reinforcement learning — could make such robots a reality. “We’ve seen really wonderful progress in AI in the digital world with tools like GPT,” says Ilija Radosavovic, a computer scientist at the University of California, Berkeley. “But I think that AI in the physical world has the potential to be even more transformational.” The state-of-the-art software that controls the movements of bipedal bots often uses what’s called model-based predictive control. It’s led to very sophisticated systems, such as the parkour-performing Atlas robot from Boston Dynamics. But these robot brains require a fair amount of human expertise to program, and they don’t adapt well to unfamiliar situations. Reinforcement learning, or RL, in which AI learns through trial and error to perform sequences of actions, may prove a better approach. “We wanted to see how far we can push reinforcement learning in real robots,” says Tuomas Haarnoja, a computer scientist at Google DeepMind and coauthor of one of the Science Robotics papers. Haarnoja and colleagues chose to develop software for a 20-inch-tall toy robot called OP3, made by the company Robotis. The team not only wanted to teach OP3 to walk but also to play one-on-one soccer. “Soccer is a nice environment to study general reinforcement learning,” says Guy Lever of Google DeepMind, a coauthor of the paper. It requires planning, agility, exploration, cooperation and competition. © Society for Science & the Public 2000–2024.
Keyword: Robotics
Link ID: 29328 - Posted: 05.29.2024
By Christina Jewett Just four months ago, Noland Arbaugh had a circle of bone removed from his skull and hair-thin sensor tentacles slipped into his brain. A computer about the size of a small stack of quarters was placed on top and the hole was sealed. Paralyzed below the neck, Mr. Arbaugh is the first patient to take part in the clinical trial of humans testing Elon Musk’s Neuralink device, and his early progress was greeted with excitement. Working with engineers, Mr. Arbaugh, 30, trained computer programs to translate the firing of neurons in his brain into the act of moving a cursor up, down and around. His command of the cursor was soon so agile that he could challenge his stepfather at Mario Kart and play an empire-building video game late into the night. But as weeks passed, about 85 percent of the device’s tendrils slipped out of his brain. Neuralink’s staff had to retool the system to allow him to regain command of the cursor. Though he needed to learn a new method to click on something, he can still skate the cursor across the screen. Neuralink advised him against a surgery to replace the threads, he said, adding that the situation had stabilized. The setback became public earlier this month. And although the diminished activity was initially difficult and disappointing, Mr. Arbaugh said it had been worth it for Neuralink to move forward in a tech-medical field aimed at helping people regain their speech, sight or movement. “I just want to bring everyone along this journey with me,” he said. “I want to show everyone how amazing this is. And it’s just been so rewarding. So I’m really excited to keep going.” From a small desert town in Arizona, Mr. Arbaugh has emerged as an enthusiastic spokesman for Neuralink, one of at least five companies leveraging decades of academic research to engineer a device that can help restore function in people with disabilities or degenerative diseases. © 2024 The New York Times Company
Keyword: Robotics
Link ID: 29320 - Posted: 05.23.2024