Chapter 3. Neurophysiology: The Generation, Transmission, and Integration of Neural Signals

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By Abby Olena The gut-brain axis is line of communication between the two organs, involved in everything from brain development to the progression of neurological diseases, with gut microbiota often pitching in to the conversation. In a study published today (May 16) in Nature, researchers present evidence that multiple sclerosis (MS) may also be influenced by commensal microbes in the gut acting upon cells in the brain. They show in a mouse model of the disease that metabolites from gut bacteria alter the behavior of microglia—immune cells that reside in the brain—which in turn regulate the activity of astrocytes to promote or prevent inflammation. The authors also found evidence in vitro and in patient samples that a similar gut-brain connection exists in people with MS, suggesting that microbes and the cells that receive their signals could be targets for disease treatment. “The beauty of this paper is that it provides a very detailed mechanistic understanding of how things work,” Jonathan Kipnis, a neuroscientist at the University of Virginia who did not participate in the study, tells The Scientist. Previous research linked the microbiome and the development of MS in mice, he says, but “we never understood how the gut communicates with the brain.” In work published in Nature Medicine in 2016, Francisco Quintana of Brigham and Women’s Hospital in Boston and colleagues found part of the answer to the question of gut-brain communication. In that study, they showed that mouse and human astrocytes—star-shape glial cells—respond to molecules generated by microbes from the intestine. And because prior work from other groups had demonstrated that microglia can regulate astrocyte behavior, Quintana says, “one of the biggest unanswered questions we had is: what mediates the crosstalk between microglia and astrocytes?” © 1986-2018 The Scientist

Keyword: Multiple Sclerosis; Glia
Link ID: 24992 - Posted: 05.18.2018

By Shawna Williams Even as patients with Parkinson’s disease, obsessive-compulsive disorder, and other conditions turn to deep brain stimulation (DBS) to keep their symptoms in check, it’s been unclear to scientists why the therapy works. Now, researchers in Texas report that in mice, the treatment dials the activity of hundreds of genes up or down in brain cells. Their results, published in eLife March 23, hint that DBS’s use could be expanded to include improving learning and memory in people with intellectual disabilities. “The paper is very well done. . . . It’s really a rigorous study,” says Zhaolan “Joe” Zhou, a neuroscientist at the University of Pennsylvania’s Perelman School of Medicine who reviewed the paper for eLife. Now that the genes and pathways DBS affects are known, researchers can home in on ways to improve the treatment, or perhaps combine the therapy with pharmacological approaches to boost its effect, he says. In DBS, two electrodes are surgically implanted in a patient’s brain (the area depends on the disorder being treated), and connected to generators that are placed in the chest. Gentle pulses of electricity are then passed continuously through the electrodes. The treatment reduces motor symptoms in many people with Parkinson’s, and allows some patients to reduce their use of medications, but it does not eliminate symptoms or slow the disease’s progression. In addition to its use in movement disorders, DBS is being explored as a potential therapy for a range of other brain-related disorders. For instance, as a way to boost learning and memory in people with Alzheimer’s disease, researchers are looking into stimulating the fimbria-fornix, a brain region thought to regulate the activity of the memory-storing hippocampus. © 1986-2018 The Scientist

Keyword: Parkinsons; Epigenetics
Link ID: 24982 - Posted: 05.16.2018

By PAM BELLUCK PORTLAND, Ore. — By the time her mother received the doctor’s email, Yuna Lee was already 2 years old, a child with a frightening medical mystery. Plagued with body-rattling seizures and inconsolable crying, she could not speak, walk or stand. “Why is she suffering so much?” her mother, Soo-Kyung Lee, anguished. Brain scans, genetic tests and neurological exams yielded no answers. But when an email popped up suggesting that Yuna might have a mutation on a gene called FOXG1, Soo-Kyung froze. “I knew,” she said, “what that gene was.” Almost no one else in the world would have had any idea. But Soo-Kyung is a specialist in the genetics of the brain—“a star,” said Robert Riddle, a program director in neurogenetics at the National Institute of Neurological Disorders and Stroke. For years, Soo-Kyung, a developmental biologist at Oregon Health and Science University, had worked with the FOX family of genes. “I knew how critical FOXG1 is for brain development,” she said. She also knew harmful FOXG1 mutations are exceedingly rare and usually not inherited — the gene mutates spontaneously during pregnancy. Only about 300 people worldwide are known to have FOXG1 syndrome, a condition designated a separate disorder relatively recently. The odds her own daughter would have it were infinitesimal. “It is an astounding story,” Dr. Riddle said. “A basic researcher working on something that might help humanity, and it turns out it directly affects her child.” Suddenly, Soo-Kyung, 42, and her husband Jae Lee, 57, another genetics specialist at O.H.S.U., had to transform from dispassionate scientists into parents of a patient, desperate for answers. © 2018 The New York Times Company

Keyword: Development of the Brain; Genes & Behavior
Link ID: 24897 - Posted: 04.24.2018

An epilepsy drug that can damage unborn babies must no longer be prescribed to girls and women of childbearing age in the UK unless they sign a form to say that they understand the risks. Drug regulator the MHRA says the new measures it's introducing will keep future generations of children safe. Those already on valproate medication should see their GP to have their treatment reviewed. No woman or girl should stop taking it without medical advice though. It is thought about 20,000 children in the UK have been left with disabilities caused by valproate since the drug was introduced in the 1970s. Affected families have called for a public inquiry and compensation. Epilepsy charities say one in five women on sodium valproate are unaware that taking it during pregnancy can harm the development and physical health of an unborn baby. Image caption This warning has been on the outside of valproate pill packets since 2016 in Britain And more than one in four have not been given information about risks for their unborn child. The MHRA has changed the licence for valproate, which means any doctor prescribing it will have to ensure female patients are put on a Pregnancy Prevention Programme, © 2018 BBC

Keyword: Development of the Brain; Epilepsy
Link ID: 24894 - Posted: 04.24.2018

By SHEILA KAPLAN WASHINGTON — A Food and Drug Administration advisory panel on Thursday unanimously recommended approval of an epilepsy medication made with an ingredient found in marijuana. If the agency follows the recommendation, as is expected, the drug would be the first cannabis-derived prescription medicine available in the United States. The drug, called Epidiolex, is made by GW Pharmaceuticals, a British company. Its active ingredient, cannabidiol, also called CBD, is one of the chemical compounds found in the cannabis plant, but it does not contain the properties that make people high. That makes it different from the “medical marijuana” allowed by a growing number of states. In those cases, certain patients are legally authorized to smoke or ingest marijuana to treat severe pain, nausea and other ailments. There are already several drugs on the market that are derived from synthetic versions of THC and other chemicals of the cannabis plant, generally used to ease nausea in cancer patients, and to help AIDS patients avoid weight loss. Advocates for development of marijuana-based treatments, and those pushing for better treatments of epilepsy, were pleased with the panel’s recommendation. “This is a very good development, and it basically underscores that there are medicinal properties to some of the cannabinoids,” said Dr. Igor Grant, director of the Center for Medicinal Cannabis Research at the University of California San Diego. “I think there could well be other cannabinoids that are of therapeutic use, but there is just not enough research on them to say.” © 2018 The New York Times Company

Keyword: Epilepsy; Drug Abuse
Link ID: 24889 - Posted: 04.21.2018

Nicky Phillips Before playing a guitar, musicians tune the strings to particular frequencies to get the pitch they want. Starting this week, a team of neuroscientists in Australia will apply a similar tuning process to human brains as part of a study to recalibrate abnormal neural patterns to a healthy state. The group, at Monash University in Melbourne, is conducting one of the first trials to use electrodes on people’s scalps, both to monitor their brain activity and to provide customized electrical stimulation. By tuning groups of neurons to specific frequencies, the team will attempt to alleviate people’s depression and other mood disorders. The Monash team is one of several around the world experimenting with such ‘closed loop’ systems — where stimulation is directed by the patient’s brain activity, which is in turn altered by the stimulation. “They’re doing something right at the cutting edge,” says Charlotte Stagg, a neurophysiologist at the University of Oxford, UK. “It’ll be pretty cool if they can get it to work.” Researchers hope such techniques will offer a better way than current stimulation techniques to correct abnormal brain patterns. Although at an early stage, the approach is a fundamental shift in the field and seeks to offer more personalization than is possible with brain-stimulation treatments routinely used in the clinic. Other teams, in the United States and Europe, have trialled closed-loop brain stimulation to treat Parkinson’s disease and for cognitive training, but the Melbourne team is among the first to use this approach for mood disorders. © 2018 Macmillan Publishers Limited,

Keyword: Depression
Link ID: 24829 - Posted: 04.06.2018

By Rachel Aviv Before having her tonsils removed, Jahi McMath, a thirteen-year-old African-American girl from Oakland, California, asked her doctor, Frederick Rosen, about his credentials. “How many times have you done this surgery?” Hundreds of times, Rosen said. “Did you get enough sleep last night?” He’d slept fine, he responded. Jahi’s mother, Nailah Winkfield, encouraged Jahi to keep asking questions. “It’s your body,” she said. “Feel free to ask that man whatever you want.” Jahi had begged not to get the surgery, but her mother promised that it would give her a better life. Jahi had sleep apnea, which left her increasingly fatigued and unable to focus at school. She snored so loudly that she was too embarrassed to go to slumber parties. Nailah had brought up four children on her own, and Jahi, her second, was her most cautious. When she saw news on television about wars in other countries, she would quietly ask, “Is it going to come here?” Her classmates made fun of her for being “chunky,” and she absorbed the insults without protest. A few times, Nailah went to the school and asked the teachers to control the other students. The operation, at Oakland’s Children’s Hospital, took four hours. When Jahi awoke, at around 7 p.m. on December 9, 2013, the nurses gave her a grape Popsicle to soothe her throat. About an hour later, Jahi began spitting up blood. The nurses told her not to worry and gave her a plastic basin to catch it in. A nurse wrote in her medical records that she encouraged Jahi to “relax and not cough if possible.” By nine that night, the bandages packing Jahi’s nose had become bloody, too. Nailah’s husband, Marvin, a truck driver, repeatedly demanded that a doctor help them. A nurse told him that only one family member was allowed in the room at a time. He agreed to leave. © 2018 Condé Nast.

Keyword: Consciousness
Link ID: 24827 - Posted: 04.06.2018

By Daniela Carulli In 1898, Camillo Golgi, an eminent Italian physician and pathologist, published a landmark paper on the structure of “nervous cells.” In addition to the organelle that still bears his name, the Golgi apparatus, he described “a delicate covering” surrounding neurons’ cell bodies and extending along their dendrites. That same year, another Italian researcher, Arturo Donaggio, observed that these coverings, now known as perineuronal nets (PNNs), had openings in them, through which, he correctly surmised, axon terminals from neighboring neurons make synapses. Since then, however, PNNs have been largely neglected by the scientific community—especially after Santiago Ramón y Cajal, a fierce rival of Golgi (who would later share the Nobel Prize with him), dismissed them as a histological artifact. It wasn’t until the 1970s, thanks to the improvement of histological techniques and the development of immunohistochemistry, that researchers confirmed the existence of PNNs around some types of neurons in the brain and spinal cord of many vertebrate species, including humans. Composed of extracellular matrix (ECM) molecules, PNNs form during postnatal development, marking the end of what’s known as the “critical period” of heightened brain plasticity. For a while after birth, the external environment has a profound effect on the wiring of neuronal circuits and, in turn, on the development of an organism’s skills and behaviors, such as language, sensory processing, and emotional traits. But during childhood and adolescence, neuronal networks become more fixed, allowing the individual to retain the acquired functions. Evidence gathered over the past 15 years suggests that PNNs contribute to this fixation in many brain areas, by stabilizing the existing contacts between neurons and repelling incoming axons. © 1986-2018 The Scientist

Keyword: Learning & Memory; Brain imaging
Link ID: 24815 - Posted: 04.03.2018

Rachel Ehrenberg BOSTON — Getting your groove on solo with headphones on might be your jam, but it can’t compare with a live concert. Just ask your brain. When people watch live music together, their brains waves synchronize, and this brain bonding is linked with having a better time. The new findings, reported March 27 at a Cognitive Neuroscience Society meeting, are a reminder that humans are social creatures. In western cultures, performing music is generally reserved for the tunefully talented, but this hasn’t been true through much of human history. “Music is typically linked with ritual and in most cultures is associated with dance,” said neuroscientist Jessica Grahn of Western University in London, Canada. “It’s a way to have social participation.” Study participants were split into groups of 20 and experienced music in one of three ways. Some watched a live concert with a large audience, some watched a recording of the concert with a large audience, and some watched the recording with only a few other people. Each person wore EEG caps, headwear covered with electrodes that measure the collective behavior of the brain’s nerve cells. The musicians played an original song they wrote for the study. The delta brain waves of audience members who watched the music live were more synchronized than those of people in the other two groups. Delta brain waves fall in a frequency range that roughly corresponds to the beat of the music, suggesting that beat drives the synchronicity, neuroscientist Molly Henry, a member of Grahn’s lab, reported. The more synchronized a particular audience member was with others, the more he or she reported feeling connected to the performers and enjoying the show. |© Society for Science & the Public 2000 - 2018

Keyword: Hearing
Link ID: 24800 - Posted: 03.30.2018

Fergus Walsh Doctors say a stem cell transplant could be a "game changer" for many patients with multiple sclerosis. Results from an international trial show that it was able to stop the disease and improve symptoms. It involves wiping out a patient's immune system using cancer drugs and then rebooting it with a stem cell transplant. Louise Willetts, 36, from Rotherham, is now symptom-free and told me: "It feels like a miracle." A total of 100,000 people in the UK have MS, which attacks nerves in the brain and spinal cord. Just over 100 patients took part in the trial, in hospitals in Chicago, Sheffield, Uppsala in Sweden and Sao Paolo in Brazil. They all had relapsing remitting MS - where attacks or relapses are followed by periods of remission. The interim results were released at the annual meeting of the European Society for Bone and Marrow Transplantation in Lisbon. The patients received either haematopoietic stem cell transplantation (HSCT) or drug treatment. After one year, only one relapse occurred among the stem cell group compared with 39 in the drug group. After an average follow-up of three years, the transplants had failed in three out of 52 patients (6%), compared with 30 of 50 (60%) in the control group. Those in the transplant group experienced a reduction in disability, whereas symptoms worsened in the drug group. Prof Richard Burt, lead investigator, Northwestern University Chicago, told me: "The data is stunningly in favour of transplant against the best available drugs - the neurological community has been sceptical about this treatment, but these results will change that. Prof John Snowden, director of blood and bone marrow transplantation at Sheffield's Royal Hallamshire Hospital, told me: "We are thrilled with the results - they are a game changer for patients with drug resistant and disabling multiple sclerosis". © 2018 BBC

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 24767 - Posted: 03.19.2018

Laura Sanders We can’t see it, but brains hum with electrical activity. Brain waves created by the coordinated firing of huge collections of nerve cells pinball around the brain. The waves can ricochet from the front of the brain to the back, or from deep structures all the way to the scalp and then back again. Called neuronal oscillations, these signals are known to accompany certain mental states. Quiet alpha waves ripple soothingly across the brains of meditating monks. Beta waves rise and fall during intense conversational turns. Fast gamma waves accompany sharp insights. Sluggish delta rhythms lull deep sleepers, while dreamers shift into slightly quicker theta rhythms. Researchers have long argued over whether these waves have purpose, and what those purposes might be. Some scientists see waves as inevitable but useless by-products of the signals that really matter — messages sent by individual nerve cells. Waves are simply a consequence of collective neural behavior, and nothing more, that view holds. But a growing body of evidence suggests just the opposite: Instead of by-products of important signals, brain waves are key to how the brain operates, routing information among far-flung brain regions that need to work together. MIT’s Earl Miller is among the neuro­scientists amassing evidence that waves are an essential part of how the brain operates. Brain oscillations deftly route information in a way that allows the brain to choose which signals in the world to pay attention to and which to ignore, his recent studies suggest. |© Society for Science & the Public 2000 - 2018

Keyword: Attention
Link ID: 24750 - Posted: 03.14.2018

By Ruth Williams When optogenetics burst onto the scene a little over a decade ago, it added a powerful tool to neuroscientists’ arsenal. Instead of merely correlating recorded brain activity with behaviors, researchers could control the cell types of their choosing to produce specific outcomes. Light-sensitive ion channels (opsins) inserted into the cells allow neuronal activity to be controlled by the flick of a switch. Nevertheless, MIT’s Edward Boyden says more precision is needed. Previous approaches achieved temporal resolution in the tens of milliseconds, making them a somewhat blunt instrument for controlling neurons’ millisecond-fast firings. In addition, most optogenetics experiments have involved “activation or silencing of a whole set of neurons,” he says. “But the problem is the brain doesn’t work that way.” When a cell is performing a given function—initiating a muscle movement, recalling a memory—“neighboring neurons can be doing completely different things,” Boyden explains. “So there is a quest now to do single-cell optogenetics.” Illumination techniques such as two-photon excitation with computer-generated holography (a way to precisely sculpt light in 3D) allow light to be focused tightly enough to hit one cell. But even so, Boyden says, if the targeted cell body lies close to the axons or dendrites of neighboring opsin-expressing cells, those will be activated too. © 1986-2018 The Scientist

Keyword: Brain imaging
Link ID: 24732 - Posted: 03.08.2018

Children and adults who spend a lot of time outside in the summer may be less likely to develop multiple sclerosis years later, a U.S. study suggests. Sun exposure is thought to lessen the risk of MS, a chronic disease in which a person's immune system targets nerve cells in the brain and spinal cord, leading to damage. It is estimated Canada may have among the highest prevalence of MS in the world. While the disease is common, little is known about its causes. But for more than 10 years, sun exposure has been thought to be linked to MS risk. Previously, researchers focused on how UV-B rays from sunlight seem protective during childhood years. Now, University of British Columbia neurology professor Helen Tremlett and her co-authors have taken a broader view, extending the association into adulthood. In Wednesday's online issue of the journal Neurology, Tremlett and her team report combing through data on 151 women with MS and 235 others of similar age without the disease who were all participating in the Nurses' Health Study based in Boston. The long-running U.S. study is one of the largest investigations into risk factors such as diet, hormones, and environment for major chronic diseases in women. "We found that just generally going out in the summer was a beneficial thing and didn't matter so much if you were exposing yourself to direct sunlight. It was just going out in the summer that was associated with a reduced risk," Tremlett said in an interview. ©2018 CBC/Radio-Canada.

Keyword: Multiple Sclerosis; Biological Rhythms
Link ID: 24731 - Posted: 03.08.2018

A small group of cells in the brain can have a big effect on seizures and memory in a mouse model of epilepsy. According to a new study in Science, loss of mossy cells may contribute to convulsive seizures in temporal lobe epilepsy (TLE) as well as memory problems often experienced by people with the disease. The study was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. “The role of mossy cells in epilepsy has been debated for decades. This study reveals how critical these cells are in the disease, and the findings suggest that preventing loss of mossy cells or finding ways to activate them may be potential therapeutic targets,” said Vicky Whittemore, Ph.D., program director at NINDS. Mossy cells, named for the dense moss-like protrusions that cover their surface, are located in the hippocampus, a brain area that is known to play key roles in memory. Loss of mossy cells is associated with TLE, but it is unknown what role that plays in the disease. Using state-of-the-art tools, Ivan Soltesz, Ph.D., professor of neurosurgery and neurosciences at Stanford University, Palo Alto, California, and his team were able to turn mossy cells on and off to track their effects in a mouse model of epilepsy. “This study would not have been possible without the rapid advancement of technology, thanks in part to the BRAIN Initiative, which has encouraged scientists to develop innovative instruments and new ways to look at the brain,” said Dr. Soltesz. “It’s remarkable that we can manipulate specific brain cells in the hippocampus of a mouse. Using 21st century tools brings us closer than ever to unlocking the mysteries behind this debilitating disease.”

Keyword: Epilepsy; Learning & Memory
Link ID: 24669 - Posted: 02.16.2018

By Diana Kwon When optogenetics debuted over a decade ago, it quickly became the method of choice for many neuroscientists. By using light to selectively control ion channels on neurons in living animal brains, researchers could see how manipulating specific neural circuits altered behavior in real time. Since then, scientists have used the technique to study brain circuity and function across a variety of species, from fruit flies to monkeys—the method is even being tested in a clinical trial to restore vision in patients with a rare genetic disorder. Today (February 8) in Science, researchers report successfully conducting optogenetics experiments using injected nanoparticles in mice, inching the field closer to a noninvasive method of stimulating the brain with light that could one day have therapeutic uses. “Optogenetics revolutionized how we all do experimental neuroscience in terms of exploring circuits,” says Thomas McHugh, a neuroscientist at the RIKEN Brain Science Institute in Japan. However, this technique currently requires a permanently implanted fiber—so over the last few years, researchers have started to develop ways to stimulate the brain in less invasive ways. A number of groups devised such techniques using magnetic fields, electric currents, and sound. McHugh and his colleagues decided to try another approach: They chose near-infrared light, which can more easily penetrate tissue than the blue-green light typically used for optogenetics. “What we saw as an advantage was a kind of chemistry-based approach in which we can harness the power of near-infrared light to penetrate tissue, but still use this existing toolbox that's been developed over the last decade of optogenetic channels that respond to visible light,” McHugh says. © 1986-2018 The Scientist

Keyword: Brain imaging
Link ID: 24637 - Posted: 02.09.2018

By Helen Shen Noninvasive brain stimulation is having its heyday, as scientists and hobbyists alike look for ways to change the activity of neurons without cutting into the brain and implanting electrodes. One popular set of techniques, called transcranial electrical stimulation (TES), delivers electrical current via electrodes stuck to the scalp, typically above the target brain area. In recent years a number of studies have attributed wide-ranging benefits to TES including enhancing memory, improving math skills, alleviating depression and even speeding recovery from stroke. Such results have also spawned a cottage industry providing commercial TES kits for DIY brain hackers seeking to boost their mind power. But little is known about how TES actually interacts with the brain, and some studies have raised serious doubts about the effectiveness of these techniques. A study published on February 2 in Nature Communications ups the ante, reporting that conventional TES techniques do not deliver enough current to activate brain circuits or modulate brain rhythms. The electrical currents mostly fizzle out as they pass through the scalp and skull. “Anybody who has published a positive effect in this field is probably not going to like our paper,” says György Buzsáki, a neuroscientist at New York University and a senior author of the study. The mechanisms behind TES have remained mysterious, in part because without penetrating the skull, researchers cannot measure neural responses while they apply stimulation. Conventional TES methods produce electrical noise that swamps any brain activity detected on the scalp. © 2018 Scientific American

Keyword: Learning & Memory
Link ID: 24622 - Posted: 02.06.2018

Jon Hamilton When Sarah Jay had her first seizure, she was in her mid-20s and working a high-stress job at a call center in Springfield, Mo. "I was going to go on break," she says. "I was heading towards the bathroom and then I fell and passed out." An ambulance took Jay to the hospital but doctors there couldn't find anything wrong. Jay figured it was a one-time thing. Then a week later, she had another seizure. And that kept happening once or twice a week. "So I was put on short-term disability for my work to try to figure out what was going on," says Jay, who's now 29. The most likely cause for her seizures was abnormal electrical activity in her brain. In other words, epilepsy. But Jay's doctors wanted to be sure. In May 2013, they admitted her to a hospital epilepsy center, put electrodes on her scalp and began watching her brain activity. An epileptic seizure looks a bit like an electrical storm in the brain. Neurons begin to fire uncontrollably, which can cause patients to lose consciousness or have muscle spasms. But during Jay's seizures, her brain activity appeared completely normal. "It was kind of surreal," she says. "This woman, she sat me down and she was like, 'OK, you do not have epilepsy.' And I'm like, 'OK, so what's going on?' " The woman told Jay her seizures were the result of a psychological disorder called psychogenic non-epileptic seizures. PNES is a surprisingly common disorder, says John Stern, who directs the epilepsy clinical program at the University of California, Los Angeles. About 1 in 3 people who come to UCLA for uncontrolled seizures don't have epilepsy. Usually, they have PNES, he says. © 2018 npr

Keyword: Epilepsy; Stress
Link ID: 24606 - Posted: 02.02.2018

Sara Reardon Superconducting computing chips modelled after neurons can process information faster and more efficiently than the human brain. That achievement, described in Science Advances on 26 January1, is a key benchmark in the development of advanced computing devices designed to mimic biological systems. And it could open the door to more natural machine-learning software, although many hurdles remain before it could be used commercially. Artificial intelligence software has increasingly begun to imitate the brain. Algorithms such as Google’s automatic image-classification and language-learning programs use networks of artificial neurons to perform complex tasks. But because conventional computer hardware was not designed to run brain-like algorithms, these machine-learning tasks require orders of magnitude more computing power than the human brain does. “There must be a better way to do this, because nature has figured out a better way to do this,” says Michael Schneider, a physicist at the US National Institute of Standards and Technology (NIST) in Boulder, Colorado, and a co-author of the study. NIST is one of a handful of groups trying to develop ‘neuromorphic’ hardware that mimics the human brain in the hope that it will run brain-like software more efficiently. In conventional electronic systems, transistors process information at regular intervals and in precise amounts — either 1 or 0 bits. But neuromorphic devices can accumulate small amounts of information from multiple sources, alter it to produce a different type of signal and fire a burst of electricity only when needed — just as biological neurons do. As a result, neuromorphic devices require less energy to run. © 2018 Macmillan Publishers Limited

Keyword: Robotics; Learning & Memory
Link ID: 24579 - Posted: 01.27.2018

By Eli Meixler Friday’s Google Doodle celebrates the birthday of Wilder Penfield, a scientist and physician whose groundbreaking contributions to neuroscience earned him the designation “the greatest living Canadian.” Penfield would have turned 127 today. Later celebrated as a pioneering researcher and a humane clinical practitioner, Penfield pursued medicine at Princeton University, believing it to be “the best way to make the world a better place in which to live.” He was drawn to the field of brain surgery, studying neuropathy as a Rhodes scholar at Oxford University. In 1928, Penfield was recruited by McGill University in Montreal, where he also practiced at Royal Victoria Hospital as the city’s first neurosurgeon. Penfield founded the Montreal Neurological Institute with support from the Rockefeller Foundation in 1934, the same year he became a Canadian citizen. Penfield pioneered a treatment for epilepsy that allowed patients to remain fully conscious while a surgeon used electric probes to pinpoint areas of the brain responsible for setting off seizures. The experimental method became known as the Montreal Procedure, and was widely adopted. But Wilder Penfield’s research led him to another discovery: that physical areas of the brain were associated with different duties, such as speech or movement, and stimulating them could generate specific reactions — including, famously, conjuring a memory of the smell of burnt toast. Friday’s animated Google Doodle features an illustrated brain and burning toast. © 2017 Time Inc.

Keyword: Miscellaneous
Link ID: 24576 - Posted: 01.27.2018

by Ariana Eunjung Cha A new class of epilepsy medications based on an ingredient derived from marijuana could be available as soon as the second half of 2018 in the United States, pending Food and Drug Administration approval. Officials from GW Pharmaceuticals, the company that developed the drug, on Wednesday announced promising results from a study on 171 patients randomized into treatment and placebo groups. Members of the group, ages 2 to 55, have a condition called Lennox-Gastaut syndrome and were suffering from seizures that were not being controlled by existing drugs. On average they had tried and discontinued six anti-seizure treatments and were experiencing 74 “drop” seizures per month. Drop seizures involve the entire body, trunk or head and often result in a fall or other type of injury. The results, published in the Lancet, show that over a 14-week treatment period, 44 percent of patients taking the drug, called Epidiolex, saw a significant reduction in seizures, compared with 22 percent of the placebo group. Moreover, more of the patients who got the drug experienced a 50 percent or greater reduction in drop seizures. Elizabeth Thiele, director of pediatric epilepsy at Massachusetts General Hospital and lead author of the study, said the results varied depending on the patient. “For some, it does not do a whole lot. But for the people it does work in, it is priceless,” she said. “One child who comes to mind had multiple seizures a day. She had been on every medication possible,” said Thiele, a professor of neurology at Harvard Medical School. Then the patient tried the cannabis-based treatment and has been seizure-free for almost four years. “She is now talking about college options. She would have never had that conversation before. It has been life-changing.” © 1996-2018 The Washington Post

Keyword: Epilepsy; Drug Abuse
Link ID: 24573 - Posted: 01.26.2018