Chapter 5. The Sensorimotor System

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Nicola Davis A new organ involved in the sensation of pain has been discovered by scientists, raising hopes that it could lead to the development of new painkilling drugs. Researchers say they have discovered that the special cells that surround the pain-sensing nerve cells that extend into the outer layer of skin appear to be involved in sensing pain – a discovery that points to a new organ behind the feeling of “ouch!”. The scientists say the finding offers new insight into pain and could help answer longstanding conundrums. “The major question for us now is whether these cells are actually the cause for certain kinds of chronic pain disorders,” Prof Patrik Ernfors, a co-author of the research from the Karolinska Institute in Sweden, told the Guardian. Writing in the journal Science, the researchers reveal how they examined the nature of cells in the skin that, they say, have largely been overlooked. These are a type of Schwann cell, which wrap around and engulf nerve cells and help to keep them alive. The study has revealed these Schwann cells have an octopus-like shape. After examining tissues, the team found the body of the cells sits below the outer layer of the skin, but that the cells have long extensions that wrap around the ends of pain-sensing nerve cells that extend up into the epidermis, the outer layer of the skin. The scientists were surprised at the findings because it has long been believed that the endings of nerve cells in the epidermis were bare or unwrapped. “In the pain field, we talk about free nerve endings that are responsible for pain sensation. But actually they are not free,” Ernfors said. © 2019 Guardian News & Media Limited

Keyword: Pain & Touch; Glia
Link ID: 26507 - Posted: 08.16.2019

By Bret Stetka Among the human body’s many maladies, few have stumped medical researchers like those that decimate the brain. After decades of effort, effectively treating—let alone curing—neurodegenerative disorders such as Huntington’s and Alzheimer's disease has been a source of frustration for many, as old theories are questioned and clinical trials fail. Basic scientists have achieved some progress. Over the past few decades, they have made serious headway in identifying single inherited genes responsible for genetic forms of various neurodegenerative diseases such as Alzheimer’s—and also the molecular and neural mechanisms behind nongenetic, or sporadic, forms of brain maladies. Yet translating these findings into working therapies has proved challenging. With genetic engineering technologies, such as CRISPR, that literally rewrite our DNA still a ways away from routine use, a number of clinical researchers have turned to a more immediate genome-based approach to treat disorders of the brain: manipulating RNA to modify levels of proteins associated with disease. DNA provides our genetic code, with its sister molecule RNA translating that code into the proteins that run our brains and myriad bodily functions. Scientists can now use molecules called antisense oligonucleotides (ASOs) to modify this process by binding to RNA and altering translation. ASOs are DNA-like molecules that greatly resemble the DNA that produced the RNA they correspond to in the first place. Depending on where they are designed to bind, these antisense molecules can prevent an RNA from being translated into a protein, which reduces levels of that protein in the body or brain. Alternatively, these same DNA-like molecules can be crafted to interfere with RNA machinery that normally inhibits or slows translation. In this case, more protein is made. © 2019 Scientific American

Keyword: Alzheimers; ALS-Lou Gehrig's Disease
Link ID: 26504 - Posted: 08.15.2019

Anna Moore On a lazy Sunday morning in May last year, Isobel Lloyd was at her boyfriend’s house, having coffee with his mum. The conversation had worked around to Lloyd’s grandma – her mother’s mother – who’d died in her 50s, when Lloyd was very young. Lloyd’s only memories of her had been hospice visits where her grandma lay bedbound, unable to talk or swallow, with no control over how her body moved. Lloyd had forgotten the name of her grandma’s disease, hadn’t thought about it in years. Like most 20-year-olds, she was future-focused – a student from Yorkshire, keen on her studies, in love with her boyfriend of four years. Sitting in his family kitchen, they began reeling off degenerative diseases. Motor neurone. Multiple sclerosis. Parkinson’s. Alzheimer’s. Then finally Huntington’s disease (HD). In a flash of recognition, Lloyd knew that was the one her grandma had. “It just clicked,” she says. “I Googled it on my phone – and that’s when I read that it was genetic. My mum had a 50% risk of getting it – and if she did, I had a 50% risk, too.” She didn’t tell her boyfriend’s mother what she’d just learned, “But I felt the colour rush out of my face,” says Lloyd, an only child. “I thought, ‘No way, that can’t be true.’ I was 20 years old and no one had told me?” In fact, that’s not so unusual. Secrecy, evasion and lies are frequent features for families grappling with genetic disease. Whether it’s HD, a breast cancer gene, inheritable bowel cancer, early-onset Alzheimer’s, it’s not uncommon for younger generations to stumble upon their inheritance by noticing patterns, asking questions. By then, they’re faced not just with their frightening at-risk status, but also anger at all those years in the dark. © 2019 Guardian News & Media Limited

Keyword: Huntingtons; Genes & Behavior
Link ID: 26498 - Posted: 08.15.2019

A new study analyzing samples from patients with and without acute flaccid myelitis (AFM) provides additional evidence for an association between the rare but often serious condition that causes muscle weakness and paralysis, and infection with non-polio enteroviruses. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, funded the research, which was conducted by investigators at Columbia University’s Center for Infection and Immunity and investigators from the Centers for Disease Control and Prevention. The findings are reported in the online journal mBio. There have been 570 confirmed cases since CDC began tracking AFM in August 2014. AFM outbreaks were reported to the CDC in 2014, 2016 and 2018. AFM affects the spinal cord and is characterized by the sudden onset of muscle weakness in one or more limbs. Spikes in AFM cases, primarily in children, have coincided in time and location with outbreaks of EV-D68 and a related enterovirus, EV-A71. Both of these viruses typically cause mild respiratory illness from which most people recover fully. Despite the epidemiological link between enterovirus circulation and AFM cases, evidence of direct causality has not been found. The researchers first looked for direct evidence of enterovirus infection in the cerebrospinal fluid (CSF) of 13 children and one adult diagnosed with AFM in 2018. They also examined five CSF samples taken from people with other central nervous system diseases. The team used a new tool they developed called VirCapSeq-VERT, which can detect any viral genetic material that is at least 60% like that of any known vertebrate virus. They found enteroviral genetic material (EV-A71) in only the one adult AFM case and genetic material from another enterovirus (echovirus 25) in one of the non-AFM cases.

Keyword: Movement Disorders; Neuroimmunology
Link ID: 26493 - Posted: 08.13.2019

By Sandra G. Boodman Galen Warden was lying in a hot bath after a punishing week at her demanding marketing job. Her neck and shoulders were, as usual, in knots, so Warden thought she’d expedite the relaxation that a restorative soak usually delivered by sliding under the water. When she sat up about 30 seconds later, Warden recalled, “it felt like my entire scalp was on fire.” Her face, neck and shoulders were unaffected, but her scalp felt as though it had been doused with acid. It would take nearly three months before the cause of Warden’s unusual symptom, which was repeatedly attributed to a tension headache, was revealed. During that time, the emergence of other symptoms failed to prompt the specialist treating her to reconsider her initial diagnosis. If anything, the new problems seemed to harden the doctor’s conviction that Warden’s problem was stress-related. Looking back, Warden said she is struck by what she characterizes as her medical naivete. "It's been a cautionary tale for my friends," she said. "I can't believe I kept going back to a well that was dry." Shocked by the fiery sensation engulfing her scalp, Warden turned on the shower and ran cool water over her head, frantically trying to think about what might have triggered it. She hadn’t rubbed her scalp hard or used a different shampoo or bath product. © 1996-2019 The Washington Post

Keyword: Pain & Touch
Link ID: 26485 - Posted: 08.12.2019

Cassandra Willyard Rob Summers was flat on his back at a rehabilitation institute in Kentucky when he realized he could wiggle his big toe. Up, down, up, down. This was new — something he hadn’t been able to do since a hit-and-run driver left him paralysed from the chest down. When that happened four years earlier, doctors had told him that he would never move his lower body again. Now he was part of a pioneering experiment to test the power of electrical stimulation in people with spinal-cord injuries. “Susie, look, I can wiggle my toe,” Summers said. Susan Harkema, a neurophysiologist at the University of Louisville in Kentucky, sat nearby, absorbed in the data on her computer. She was incredulous. Summers’s toe might be moving, but he was not in control. Of that she was sure. Still, she decided to humour him. She asked him to close his eyes and move his right toe up, then down, and then up. She moved on to the left toe. He performed perfectly. “Holy shit,” Harkema said. She was paying attention now. “How is that happening?” he asked. “I have no idea,” she replied. Summers had been a university baseball player with major-league ambitions before the vehicle that struck him snapped all the ligaments and tendons in his neck, allowing one of his vertebra to pound the delicate nerve tissue it was meant to protect. Doctors classified the injury as complete; the motor connections to his legs had been wiped out. When Harkema and her colleagues implanted a strip of tiny electrodes in his spine in 2009, they weren’t trying to restore Summers’s ability to move on his own. Instead, the researchers were hoping to demonstrate that the spine contains all the circuitry necessary for the body to stand and to step. They reasoned that such an approach might allow people with spinal-cord injuries to stand and walk, using electrical stimulation to replace the signals that once came from the brain.

Keyword: Robotics
Link ID: 26471 - Posted: 07.31.2019

By Dom Vukovic Robotic skeletons may sound like something out of a science fiction movie but they are now being used to help people with severe spinal cord injuries take their first steps. The device known as a Rex bionic exoskeleton is one of only a few in the country and researchers in a trial have named their protype HELLEN. In a joint initiative between the University of Newcastle and the Australian Institute of Neuro-Rehabilitation, the robot is being used as a therapy device to see if it can help improve health and mobility outcomes in people with conditions including stroke, multiple sclerosis and now quadriplegia. Chief investigator Jodie Marquez said the trial was one of the first in the world to capture data about physiological and neurological changes that might occur in patients who undergo therapy while wearing the robotic suit. "We're seeing whether exercising in the exoskeleton device can improve both real measures of strength and spasticity, but also bigger measures such as mood and quality of life and function," Dr Marquez said. "I have no doubt that robotics will become a part of rehabilitation and a part of our lives in the future, I think that's unquestionable." Lifesaver Jess Collins is the first person with severe spinal injuries to participate in the trial. She had a near fatal surfing accident while on holidays with friends in May last year leaving her paralysed from the chest down. "I've hit the board and then the sandbank and then instantly I didn't have any movement or feeling and I wasn't sure where I was placed in the water … I was face down, which was horrific and I was conscious the entire time," she said. © 2019 ABC

Keyword: Robotics
Link ID: 26460 - Posted: 07.29.2019

Anna Ploszajski A man who lost his hand 17 years ago has been given the sense of touch through a brain-controlled robotic prosthetic. Keven Walgamott, whose arm was amputated below the elbow after an accident, can now feel 119 different touch sensations through the prosthetic as if it were his own limb. He is able to distinguish between large, small, soft and hard objects when blindfolded, and handle delicate objects such as grapes and eggs. Everyday tasks such as putting on his wedding ring, peeling a banana or holding a mobile phone are now possible. “The most amazing thing for me is what the team was able to do,” said Walgamott. “[They] take a bunch of mechanical pieces and provide, through a computer, not only the ability to move all fingers and grasp things but be able to feel again.” The prosthetic hand and wrist has been in development for 15 years. Electrodes were implanted in the remaining part of his arm, allowing communication between the prosthetic hand and his brain. The hand can move in six directions and is equipped with 19 sensors that detect touch and positioning. The arrays interpret the signals Walgamott’s brain sends to his arm nerves, and a computer outside the body translates these into digital information, which then instructs the prosthetic to move as the wearer intends. They also provide Walgamott’s nerves with computer-generated touch signals from the prosthesis, which are then interpreted by his brain. © 2019 Guardian News & Media Limited

Keyword: Pain & Touch; Robotics
Link ID: 26449 - Posted: 07.25.2019

Tina Hesman Saey A friendly gut bacterium can help lessen ALS symptoms, a study of mice suggests. Mice that develop a degenerative nerve disease similar to amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease, fared better when bacteria making vitamin B3 were living in their intestines, researchers report July 22 in Nature. Those results suggest that gut microbes may make molecules that can slow progression of the deadly disease. The researchers uncovered clues that the mouse results may also be important for people with ALS. But the results are too preliminary to inform any changes in treating the disease, which at any given time affects about two out of every 100,000 people, or about 16,000 people in the United States, says Eran Elinav, a microbiome researcher at the Weizmann Institute of Science in Rehovot, Israel. “With respect to ALS, the jury is still out,” says Elinav, also of the German Cancer Research Center in Heidelberg. “We have to prove that what we found in mice is reproducibly found in humans.” Elinav and his colleagues examined the gut microbiomes — bacteria, archaea and other microbes that live in the colon, or large intestine — of mice that produce large amounts of a mutated form of the SOD1 protein. In the mice, as in human ALS patients, faulty SOD1 proteins clump together and lead to the death of nerve cells. |© Society for Science & the Public 2000 - 2019

Keyword: ALS-Lou Gehrig's Disease
Link ID: 26439 - Posted: 07.23.2019

By Tanya Lewis Late on Tuesday evening, Elon Musk, the charismatic and eccentric CEO of SpaceX and Tesla, took to the stage at the California Academy of Sciences to make a big announcement. This time, he was not unveiling a new rocket or electric car but a system for recording the activity of thousands of neurons in the brain. With typical panache, Musk talked about putting this technology into a human brain by as early as next year. The work is the product of Neuralink, a company Musk founded in 2016 to develop a high-bandwidth, implantable brain-computer interface (BCI). He says the initial goal is to enable people with quadriplegia to control a computer or smartphone using just their thoughts. But Musk’s vision is much more ambitious than that: he seeks to enable humans to “merge” with AI, giving people superhuman intelligence—an objective that is much more hype than an actual plan for new technology development. Neuralink prototype device. Credit: Neuralink On a more practical note, “the goal is to record from and stimulate [signals called] spikes in neurons” with an order of magnitude more bandwidth than what has been done to date and to have it be safe, Musk said at Tuesday’s event, which was livestreamed. Advertisement The system unveiled last night was a long way from Musk’s sci-fi vision. But it was nonetheless marked an impressive technical development. The team says it has now developed arrays with a very large number of “channels”—up to 3,072 flexible electrodes—which can be implanted in the brain’s outer layer, or cortex, using a surgical robot (a version of which was described as a “sewing machine” in a preprint paper posted on bioRxiv earlier this year). The electrodes are packaged in a small, implantable device containing custom-built integrated circuits, which connects to a USB port outside the brain (the team hopes to ultimately make the port wireless). © 2019 Scientific American

Keyword: Brain imaging; Regeneration
Link ID: 26427 - Posted: 07.18.2019

Shuai Xu, Arun Jayaraman and John A. Rogers. Thin, soft electronic systems that stick onto skin are beginning to transform health care. Millions of early versions1 of sensors, computers and transmitters woven into flexible films, patches, bandages or tattoos are being deployed in dozens of trials in neurology applications alone2; and their numbers growing rapidly. Within a decade, many people will wear such sensors all the time. The data they collect will be fed into machine-learning algorithms to monitor vital signs, spot abnormalities and track treatments. Medical problems will be revealed earlier. Doctors will monitor their patients’ recovery remotely while the patient is at home, and intervene if their condition deteriorates. Epidemic spikes will be flagged quickly, allowing authorities to mobilize resources, identify vulnerable populations and monitor the safety and efficacy of drugs issued. All of this will make health care more predictive, safe and efficient. Where are we now? The first generation of biointegrated sensors can track biophysical signals, such as cardiac rhythms, breathing, temperature and motion3. More advanced systems are emerging that can track certain biomarkers (such as glucose) as well as actions such as swallowing and speech. Small companies are commercializing soft biosensor systems that measure clinical data continuously. These include Vital Connect in San Jose, California; iRhythm in San Francisco, California; MC10 in Lexington, Massachusetts; and Sibel Health in Evanston, Illinois. For example, iRhythm’s single-use Zio patch monitors electrical pulses from the heart for 14 days, and is more effective than intermittent hospital check-ups at detecting abnormal rhythms4. But it is bulky and temporary, and the data must be downloaded after use, rather than transmitted in real time.

Keyword: Pain & Touch; Robotics
Link ID: 26425 - Posted: 07.18.2019

By Knvul Sheikh A tropical parasite transmitted through rats and snails has caught the attention of health officials in Hawaii. But few scientists have studied the infection once it makes its way into humans, and researchers can’t say for certain whether the disease is becoming more widespread. The parasite, Angiostrongylus cantonensis, typically resides in a rat’s pulmonary arteries and is commonly known as “rat lungworm.” When its eggs hatch, tiny larvae are shed in the animals’ feces and eaten by snails or slugs. Those slugs, in turn, are often mistakenly eaten by people, on unwashed produce or in drinks that have been left uncovered. Although the larvae can’t grow into adult worms in a human host, they still can cause various complications, including flulike symptoms, headaches, stiff necks and bursts of nerve pain that seem to shift from one part of the body to another. M.R.I. scans suggest that the worms can also wriggle into the brain, leading to eosinophilic meningitis, which in rare cases can cause paralysis. Doctors in the state have noted cases of rat lungworm disease since at least 1959. But it is difficult to diagnose. To better track it, and to identify areas that prevention efforts should target, the Hawaii Department of Health began monitoring rat lungworm infections about a decade ago. From 2007 to 2017, officials tallied 82 cases, two of which resulted in death. Another 10 cases were reported in 2018, and six more have been reported among visitors and residents already this year. From the team at NYT Parenting: Get the latest news and guidance for parents. We'll celebrate the little parenting moments that mean a lot — and share stories that matter to families. The east side of the Big Island, in particular, has become a hot spot for infections, according to a review of cases published Monday in the American Journal of Tropical Medicine and Hygiene. Researchers are not sure why. Rats may be more numerous there, or more heavily infected, or more likely to cross paths with humans and infect them. Increased awareness about the disease may also have led to more infections being recognized than in the past. © 2019 The New York Times Company

Keyword: Pain & Touch
Link ID: 26416 - Posted: 07.13.2019

By Pam Belluck Last year, health officials confronted a record number of cases of a rare, mysterious neurological condition that caused limb weakness and paralysis in more than 200 children across the country. Officials with the Centers for Disease Control and Prevention said on Tuesday that they were still trying to understand the condition, called acute flaccid myelitis, or A.F.M. And though there have been very few cases so far this year, they urged doctors to be on the lookout because the illness has tended to emerge in late summer and early fall. A.F.M. often involves sudden muscle weakness in the legs or arms and can also include stiffness in the neck, drooping eyelids or face muscles, problems swallowing and slurred speech. The paralysis can appear similar to polio. There have been 570 recorded cases since 2014, when the C.D.C. began tracking the condition, and it appears to peak every two years from August through October. In 2018, there were 233 cases in 41 states, the largest reported outbreak so far, the agency reported Tuesday. In alternate years, there have been small numbers of cases and 2019, with 11 confirmed cases so far, is looking like other off years, C.D.C. officials said. Still, Dr. Anne Schuchat, the agency’s principal deputy director, cautioned parents and clinicians to be aware of possible symptoms and report suspected cases quickly. “We don’t right now have an explanation for the every-other-year pattern,” she said, “and we really need to be ready to rapidly detect, report and investigate each case this year and be ready for possibly a bad year this year.” © 2019 The New York Times Company

Keyword: Movement Disorders
Link ID: 26404 - Posted: 07.10.2019

By James Gallagher Health and science correspondent, BBC News Nerves inside paralysed people's bodies have been "rewired" to give movement to their arms and hands, say Australian surgeons. Patients can now feed themselves, put on make-up, turn a key, handle money and type at a computer. Paul Robinson, 36 from Brisbane, said the innovative surgery had given him independence he had never imagined. Completely normal function has not been restored, but doctors say the improvement is life-changing. How does the procedure work? Injuries to the spinal cord stop messages getting from the brain to control the rest of the body. The impact is paralysis. Patients in the trial had quadriplegia affecting movement in all their limbs. But crucially they were still able to move some muscles in their upper arms. The functioning nerves leading from the spinal cord to these muscles were then rewired. The nerves were cut and then attached to nerves that control other muscles - such as for extending the arm or opening or closing the hand. For example, nerves that once turned the palm up to face the ceiling could be used to extend all the fingers in the hand. So now when a patient thinks of rotating their hand, their fingers extend. "We believe that nerve transfer surgery offers an exciting new option, offering individuals with paralysis the possibility of regaining arm and hand functions to perform everyday tasks, and giving them greater independence and the ability to participate more easily in family and work life," said Dr Natasha van Zyl from Austin Health in Melbourne. © 2019 BBC

Keyword: Regeneration
Link ID: 26393 - Posted: 07.05.2019

Mike Power Roll up, roll up, ladies and gentleman, and gather around. Do you, your loved one – or family pet – suffer from any of the following conditions? Cancer, epilepsy, diabetes, arthritis, anxiety, menstrual cramps, insomnia, dry skin, psychosis, Alzheimer’s, dementia, anger, depression, ADHD, Crohn’s and IBS, PTSD, opiate addiction, Parkinson’s, pain of any kind, migraine, or canine uptightness? Then it’s your lucky day. All can be treated, claim the snake oil salesmen of the modern wild west, with the miracle cure-all: CBD, or cannabidiol. It’s one of the 119 cannabinoids contained in cannabis sativa, indica and ruderalis, and all hybrids thereof; aka weed. CBD is legal and doesn’t get you high – still-illegal cannabinoid THC does that job very efficiently – but it’s fair to say business is blazing. What a giddy array of products there are: from CBD water (sold in clear bottles that mean the sensitive compound swiftly degrades), to cooking or massage oils, pills, chewing gum, transdermal patches, pessaries, gin, beer and lube. The crown for silliest CBD product of the year, however, belongs indisputably to the CBD-infused pillowcases sold by one hopeful firm of US fabric-makers. Yoga classes offering CBD-assisted asanas and guided meditation have sprung up, with devotees claiming greater flexibility and elevated mood. Sellers in the UK are careful not to claim any specific medical benefits for the products because of a lack of clinical evidence, so they are instead marketed as food supplements. In this, they are supported by breathless, uncritical media reports on CBD use for airily unspecified “wellbeing” purposes. © 2019 Guardian News & Media Limited

Keyword: Drug Abuse; Sleep
Link ID: 26369 - Posted: 07.01.2019

/ By Dan Falk Suppose I give you the name of a body part, and ask you to list its main uses: I say legs, you say walking and running; I say ears, you say hearing. And if I say the brain? Well, that’s a no-brainer (so to speak); obviously the brain is for thinking. Of course, it does a bunch of other things, too; after all, when the brain ceases to function, we die — but clearly it’s where cognition happens. Tversky argues that gesturing is more than just a by-product of speech: it literally helps us think. Or is it? No one would argue that the brain isn’t vital for thinking — but quite a few 21st-century psychologists and cognitive scientists believe that the body, as well as the brain, is needed for thinking to actually happen. And it’s not just that the brain needs a body to keep it alive (that much is obvious), but rather, that the brain and the body somehow work together: it’s the combination of brain-plus-body that creates the mental world. The latest version of this proposition comes from Barbara Tversky, a professor emerita of psychology at Stanford University who also teaches at Columbia. Her new book, “Mind in Motion: How Action Shapes Thought,” is an extended argument for the interplay of mind and body in enabling cognition. She draws on many different lines of evidence, including the way we talk about movement and space, the way we use maps, the way we talk about and use numbers, and the way we gesture. Copyright 2019 Undark

Keyword: Language; Attention
Link ID: 26364 - Posted: 06.28.2019

Nicola Davis Evidence that Parkinson’s disease may start off in the gut is mounting, according to new research showing proteins thought to play a key role in the disease can spread from the gastrointestinal tract to the brain. The human body naturally forms a protein called alpha-synuclein which is found, among other places, in the brain in the endings of nerve cells. However, misfolded forms of this protein that clump together are linked to damage to nerve cells, a deterioration of the dopamine system and the development of problems with movement and speech – hallmarks of Parkinson’s disease. The latest findings, which are based on studies in mice, back up a long-held theory that abnormally folded alpha-synuclein may start off in the gut and then spread to the brain via the vagus nerve – a bundle of fibres that starts in the brainstem and transports signals to and from many of the body’s organs, including the gut. “It supports and really provides the first experimental evidence that Parkinson’s disease can start in the gut and go up the vagus nerve,” said Ted Dawson, professor of neurology at the Johns Hopkins University school of medicine and co-author of the research. The researchers say the way the misfolded alpha-synuclein spreads in the brains of the mice, and the animals’ symptoms, closely mirrors the disease in humans. Parkinson's disease 'could be detected early on by brain changes' © 2019 Guardian News & Media Limited

Keyword: Parkinsons; Obesity
Link ID: 26360 - Posted: 06.26.2019

David Barrie Until the arrival of GPS, the magnetic compass was the single most useful navigational tool available to humans. But it’s a recent invention. Although Chinese explorers understood the principles of the compass earlier, it entered service in Europe in the 12th century. Other animals have been magnetic navigators for much, much longer. Many different species—ranging from newts and insects to sea turtles, fish, and birds—are able to orient themselves relative to the Earth’s magnetic field. Among mammals, naked mole rats, deer, and even dogs also seem to have this gift. Researchers have recently shown that the brainwaves of human beings respond to changes in magnetic fields, though it’s far from clear whether or not we can make any navigational use of this effect. But how all these different species actually detect the Earth’s magnetic field remains largely mysterious. We know that certain bacteria that respond to magnetic fields carry within them crystalline chains of the mineral magnetite, which enables their alignment with the magnetic field in a passive way—just like the needle of a compass. This simple mechanism helps these microbes swim toward the oxygen-deprived depths where many species flourish. Magnetite also seems to be a promising candidate for a “magnetoreceptor” in multicellular organisms. An array of a few million cells containing magnetite could be used to detect small changes in the intensity of the Earth’s magnetic field. Magnetite is found in many organisms, and it is clearly involved in the magnetic sense possessed by some fish. © 1986–2019 The Scientist

Keyword: Animal Migration
Link ID: 26357 - Posted: 06.26.2019

Kelly Crowe · CBC News · Last fall, a dangerous animal sickness — chronic wasting disease (CWD) — was detected in a Quebec deer farm. It was a disturbing development — the first sign of this highly contagious infection outside of Alberta and Saskatchewan. There were almost 3,000 deer in the herd. Eleven tested positive for CWD. The rest — more than 2,700 animals — tested negative and were released into the food chain. It was a controversial decision, in part, because so little is known about the human health risk from CWD. The Canadian Food Inspection Agency's website cautions that: "A negative test result does not guarantee that an individual animal is not infected with CWD." "There is not currently a food safety test available for any prion disease," CFIA's spokesperson told CBC News in an email. "The tests that are used are the best available. In accordance with Health Canada's precautionary approach, no animals known to be infected were released into the human food chain." CWD is similar to another frightening animal illness — mad cow disease, officially called "bovine spongiform encephalopathy" or BSE. It is a fatal infection in cattle that can be spread to humans through beef consumption. Both CWD and BSE are caused by a strange protein — a prion — which can jump the species barrier, triggering a deadly cascade of neurological damage. Worldwide, BSE has caused about 225 cases of human prion disease called "variant Creutzfeldt Jacob Disease (vCJD)." There is no treatment and no cure. After an epidemic of mad cow disease in the U.K. more than two decades ago, governments developed strict controls to prevent BSE-infected cattle from being processed for human food. But so far there are few official controls in place to keep CWD out of the food chain.

Keyword: Prions
Link ID: 26349 - Posted: 06.24.2019

Nicola Davis Changes in the brain that can be spotted years before physical symptoms of Parkinson’s disease occur might act as an early warning sign for the condition, researchers say. It is thought that about 145,000 people in the UK are living with Parkinson’s disease, a neurological condition that can lead to mobility problems, including slowness and tremors, as well as other symptoms such as memory difficulties. There are treatments to help manage symptoms but as yet the disease cannot be slowed or cured. The researchers, based at King’s College London, say the latest findings could eventually lead to new ways to identify people who might go on to develop Parkinson’s; the discoveries could also confirm diagnoses, monitor the disease progression, and aid the development and testing of drugs. Those developments could be some way off though, some scientists have said. Most of the time Parkinson’s appears to have no known cause, so people affected by the disease are not studied before their symptoms appear. But the King’s College studies concerned with genetic mutations making the development of Parkinson’s disease more likely, could point to the warning signs. Marios Politis, a professor and lead author of the research, said: “If you carry the gene [SNCA] it means it is almost certain you are going to develop Parkinson’s in the course of your life.” © 2019 Guardian News & Media Limited

Keyword: Parkinsons; Brain imaging
Link ID: 26344 - Posted: 06.20.2019