Chapter 2. Functional Neuroanatomy: The Nervous System and Behavior

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Sara Reardon Cuttlefish are masters at altering their appearance to blend into their surroundings. But the cephalopods can no longer hide their inner thoughts, thanks to a technique that infers a cuttlefish’s brain activity by tracking the ever-changing patterns on its skin. The findings, published in Nature on 17 October1, could help researchers to better understand how the brain controls behaviour. The cuttlefish (Sepia officinalis) camouflages itself by contracting the muscles around tiny, coloured skin cells called chromatophores. The cells come in several colours and act as pixels across the cuttlefish’s body, changing their size to alter the pattern on the animal’s skin. The cuttlefish doesn’t always conjure up an exact match for its background. It can also blanket itself in stripes, rings, mottles or other complex patterns to make itself less noticeable to predators. “On any background, especially a coral reef, it can’t look like a thousand things,” says Roger Hanlon, a cephalopod biologist at the Marine Biological Laboratory in Chicago, Illinois. “Camouflage is about deceiving the visual system.” To better understand how cuttlefish create these patterns across their bodies, neuroscientist Gilles Laurent at the Max Planck Institute for Brain Research in Frankfurt, Germany, and his collaborators built a system of 20 video cameras to film cuttlefish at 60 frames per second as they swam around their enclosures. The cameras captured the cuttlefish changing colour as they passed by backgrounds such as gravel or printed images that the researchers placed in the tanks. © 2018 Springer Nature Limited.

Keyword: Vision; Brain imaging
Link ID: 25589 - Posted: 10.18.2018

By Neuroskeptic A new review paper in The Neuroscientist highlights the problem of body movements for neuroscience, from blinks to fidgeting. Authors Patrick J Drew and colleagues of Penn State discuss how many types of movements are associated with widespread brain activation, which can contaminate brain activity recordings. This is true, they say, of both humans and experimental animals such as rodents, e.g. with their ‘whisking’ movements of the whiskers. A particular concern is that many movements occur (or change in frequency) over similar timescales to some measures of neural activity – especially resting state fMRI – which means that movement-related activity could be mistaken for more interesting neural signals. Here’s how the authors describe the relationship between one kind of movement, blinking, and brain activity: Blink-related modulations are visible in BOLD functional magnetic resonance imaging (fMRI) signals in the primary visual cortex, as well as higher brain regions, such as the frontal eye field (FEF), and regions associated with the default network and somatosensory areas… If the rate of blinking were constant, ongoing blinks would not be an issue, and they would simply be averaged out. However, spontaneous eye blink rate dynamically varies on slow time scales (~0.001 Hz to 0.1 Hz), and these variations can drive correlated activity in multiple brain regions.

Keyword: Brain imaging
Link ID: 25574 - Posted: 10.15.2018

By Emily Underwood The ornately folded outer layer of the human brain, the cerebral cortex, has long received nearly all the credit for our ability to perform complex cognitive tasks such as composing a sonata, imagining the plot of a novel or reflecting on our own thoughts. One explanation for how we got these abilities is that the cortex rapidly expanded relative to body size as primates evolved — the human cortex has 10 times the surface area of a monkey’s cortex, for example, and 1,000 times that of a mouse. But the cortex is not the only brain region that has gotten bigger and more complex throughout evolution. Nestled beneath the cortex, a pair of egg-shaped structures called the thalamus has also grown, and its wiring became much more intricate as mammals diverged from reptiles. The thalamus — from the Greek thalamos, or inner chamber — transmits 98 percent of sensory information to the cortex, including vision, taste, touch and balance; the only sense that doesn’t pass through this brain region is smell. The thalamus also conducts motor signals and relays information from the brain stem to the cortex, coordinating shifts in consciousness such as waking up and falling asleep. Scientists have known for decades that the thalamus faithfully transmits information about the visual world from the retina to the cortex, leading to the impression that it is largely a messenger of sensory information rather than a center of complex cognition itself. But that limited, passive view of the thalamus is outdated, maintains Michael Halassa, a neuroscientist at the Massachusetts Institute of Technology who recently coauthored (with Ralf D. Wimmer and Rajeev V. Rikhye) an article in the Annual Review of Neuroscience exploring the thalamus’s role. © 2018 Annual Reviews, Inc

Keyword: Attention
Link ID: 25542 - Posted: 10.08.2018

By Simon Makin Neuroscientists know a lot about how individual neurons operate but remarkably little about how large numbers of them work together to produce thoughts, feelings and behavior. They need a wiring diagram for the brain—known as a connectome—to identify the circuits that underlie the organ’s functions. Now researchers at Cold Spring Harbor Laboratory and their colleagues have developed an innovative brain-mapping technique and used it to trace the connections emanating from nearly 600 neurons in a mouse brain’s main visual area in just three weeks. This technology could someday be used to help understand disorders thought to involve atypical brain wiring, such as autism or schizophrenia. The technique works by tagging cells with genetic “bar codes.” Researchers inject viruses into mice brains, where the viruses direct cells to produce random 30-letter RNA sequences (consisting of the nucleotide “letters” G, A, U and C). The cells also create a protein that binds to these RNA bar codes and drags them the length of each neuron’s output wire, or axon. The researchers later dissect the mice brains into target regions and sequence the cells in each area, enabling them to determine which tagged neurons are connected to which regions. The team found that neurons in a mouse’s primary visual cortex typically send outputs to multiple other visual areas. It also discovered that most cells fall into six distinct groups based on which regions—and how many of them—they connect to. This finding suggests there are subtypes of neurons in a mouse’s primary visual cortex that perform different functions. “Because we have so many neurons, we can do statistics and start understanding the patterns we see,” says Cold Spring Harbor’s Justus Kebschull, co-lead author of the study, which was published in April in Nature. © 2018 Scientific American

Keyword: Brain imaging; Autism
Link ID: 25527 - Posted: 10.04.2018

Giorgia Guglielmi Biophysicist Adam Cohen was strolling around San Francisco, California, in 2010, when a telephone call caught him by surprise. “We have a signal,” said the caller. Nearly 5,000 kilometres away, in Cambridge, Massachusetts, his collaborators had struck gold. After months of failed experiments, the researchers had found a fluorescent protein that allowed them to watch signals as they passed between neurons. But there was something weird going on. When Cohen got back to his lab at Harvard University, he learned that all the recordings of the experiment showed a strange progression. At first, neurons decorated with the protein flashed nicely as electric impulses whizzed through them. But then the cells turned into bright blobs. “Halfway through each recording, the signal would go all wild,” Cohen says. So he decided to join his team during an experiment. “When they started the recording, they would sit there holding their breath,” Cohen says. But as soon as they realized it was working, they would celebrate, “dancing and running around the room”. In their exuberance, they were letting the light from a desk lamp shine right onto the microscope. “We were actually recording our excitement,” says Daniel Hochbaum, then a graduate student in Cohen’s group. They toned down their celebrations, and a year later, the team published its study1 — one of the first to show that a fluorescent protein engineered into specific mammalian neurons could be used to track individual electric impulses in real time. © 2018 Springer Nature Limited

Keyword: Brain imaging
Link ID: 25478 - Posted: 09.21.2018

By Emily Underwood The human gut is lined with more than 100 million nerve cells—it’s practically a brain unto itself. And indeed, the gut actually talks to the brain, releasing hormones into the bloodstream that, over the course of about 10 minutes, tell us how hungry it is, or that we shouldn’t have eaten an entire pizza. But a new study reveals the gut has a much more direct connection to the brain through a neural circuit that allows it to transmit signals in mere seconds. The findings could lead to new treatments for obesity, eating disorders, and even depression and autism—all of which have been linked to a malfunctioning gut. The study reveals “a new set of pathways that use gut cells to rapidly communicate with … the brain stem,” says Daniel Drucker, a clinician-scientist who studies gut disorders at the Lunenfeld-Tanenbaum Research Institute in Toronto, Canada, who was not involved with the work. Although many questions remain before the clinical implications become clear, he says, “This is a cool new piece of the puzzle.” In 2010, neuroscientist Diego Bohórquez of Duke University in Durham, North Carolina, made a startling discovery while looking through his electron microscope. Enteroendocrine cells, which stud the lining of the gut and produce hormones that spur digestion and suppress hunger, had footlike protrusions that resemble the synapses neurons use to communicate with each other. Bohórquez knew the enteroendocrine cells could send hormonal messages to the central nervous system, but he also wondered whether they could “talk” to the brain using electrical signals, the way that neurons do. If so, they would have to send the signals through the vagus nerve, which travels from the gut to the brain stem. © 2018 American Association for the Advancement of Science

Keyword: Obesity; Brain imaging
Link ID: 25476 - Posted: 09.21.2018

By: Helene Benveniste, M.D., Ph.D. The brain, like other parts of the body, needs to maintain “homeostasis” (a constant state) to function, and that requires continuous removal of metabolic waste. For decades, the brain’s waste-removal system remained a mystery to scientists. A few years ago, a team of researchers—with the help of our author—finally found the answer. This discovery—dubbed the glymphatic system— will help us understand how toxic waste accumulates in devastating disorders such as Alzheimer’s disease and point to possible strategies to prevent it. In early February 2012, I received a note from Maiken Nedergaard, a renowned neuroscientist at the University of Rochester whom I knew from our time as medical students at the University of Copenhagen. She explained that her team had discovered important features of a new system that transports the fluid that surrounds the brain—a substance called cerebrospinal fluid (CSF). The discovery of how this fluid was transported in the brain, she believed, was the key to understanding how waste is cleared from the brain. Nedergaard’s work with the non-neuronal brain cells called “astroglia” had led her to suspect that these cells might play a role in CSF transport and brain cleansing. She was inspired by an older study' which showed that CSF could rapidly penetrate into channels along the brain vasculature, and astroglial cells structurally help create these channels. Now she needed help with visualizing the system in the whole brain to confirm her suspicions. Her team needed imaging scientists like myself who might be able to visualize the unique CSF flow patterns in a rodent brain and shed light on the new system. Because I had experience and expertise in imaging CSF in the small rodent brain and spinal cord, I was equipped to take on this new challenge. © 2018 The Dana Foundation.

Keyword: Brain imaging
Link ID: 25426 - Posted: 09.08.2018

Laura Sanders Skulls seem solid, but the thick bones are actually riddled with tiny tunnels. Microscopic channels cut through the skull bones of people and mice, scientists found. In mice, inflammatory immune cells use these previously hidden channels to travel from the bone marrow of the skull to the brain, the team reports August 27 in Nature Neuroscience. It’s not yet known whether immune cells travel these paths through people’s skulls. If so, these tunnels represent a newfound way for immune cells to reach — and possibly inflame — the brain. Along with other blood cells, immune cells are made in bones including those in the arm, leg, pelvis and skull. Researchers injected tracking dyes into bone marrow in the skull and other bones of mice, marking immune cells called neutrophils that originated in each locale. After a stroke, neutrophils flocked to the brain. Instead of coming equally from all sources of bone marrow, as some scientists had thought, most of these responding cells came from skull marrow, study coauthor Matthias Nahrendorf of Massachusetts General Hospital and Harvard Medical School and colleagues found. Curious about cells’ journeys from skull marrow to the brain, the researchers used powerful microscopes to look where skull meets brain. Tiny rivulets through the skull bone connected bone marrow inside the skull to the outer covering of the brain. In mice, neutrophils used these channels, which averaged about 22 micrometers across, as shortcuts to reach the brain. |© Society for Science & the Public 2000 - 2018

Keyword: Neuroimmunology
Link ID: 25411 - Posted: 09.04.2018

Megan MolteniMegan Molteni It’s been more than a century since Spanish neuroanatomist Santiago Ramón y Cajal won the Nobel Prize for illustrating the way neurons allow you to walk, talk, think, and be. In the intervening hundred years, modern neuroscience hasn’t progressed that much in how it distinguishes one kind of neuron from another. Sure, the microscopes are better, but brain cells are still primarily defined by two labor-intensive characteristics: how they look and how they fire. Which is why neuroscientists around the world are rushing to adopt new, more nuanced ways to characterize neurons. Sequencing technologies, for one, can reveal how cells with the same exact DNA turn their genes on or off in unique ways—and these methods are beginning to reveal that the brain is a more diverse forest of bristling nodes and branching energies than even Ramón y Cajal could have imagined. On Monday, an international team of researchers introduced the world to a new kind of neuron, which, at this point, is believed to exist only in the human brain. The long nerve fibers known as axons of these densely bundled cells bulge in a way that reminded their discoverers of a rose without its petals—so much that they named them “rose hip cells.” Described in the latest issue of Nature Neuroscience, these new neurons might use their specialized shape to control the flow of information from one region of the brain to another. “They can really act as a sort of brake on the system,” says Ed Lein, an investigator at the Allen Institute for Brain Science—home to several ambitious brain mapping projects—and one of the lead authors on the study. Neurons come in two basic flavors: Excitatory cells send information to the cells next to them, while inhibitory cells slow down or stop excitatory cells from firing. Rose hip cells belong to this latter type, and based on their physiology, seem to be a particularly potent current-curber. © 2018 Condé Nast

Keyword: Attention; Consciousness
Link ID: 25391 - Posted: 08.28.2018

Bone marrow, the spongy tissue inside most of our bones, produces red blood cells as well as immune cells that help fight off infections and heal injuries. According to a new study of mice and humans, tiny tunnels run from skull bone marrow to the lining of the brain and may provide a direct route for immune cells responding to injuries caused by stroke and other brain disorders. The study was funded in part by the National Institutes of Health and published in Nature Neuroscience. “We always thought that immune cells from our arms and legs traveled via blood to damaged brain tissue. These findings suggest that immune cells may instead be taking a shortcut to rapidly arrive at areas of inflammation,” said Francesca Bosetti, Ph.D., program director at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS), which provided funding for the study. “Inflammation plays a critical role in many brain disorders and it is possible that the newly described channels may be important in a number of conditions. The discovery of these channels opens up many new avenues of research.” Using state-of-the-art tools and cell-specific dyes in mice, Matthias Nahrendorf, M.D., Ph.D., professor at Harvard Medical School and Massachusetts General Hospital in Boston, and his colleagues were able to distinguish whether immune cells traveling to brain tissue damaged by stroke or meningitis, came from bone marrow in the skull or the tibia, a large legbone. In this study, the researchers focused on neutrophils, a particular type of immune cell, which are among the first to arrive at an injury site.

Keyword: Neuroimmunology
Link ID: 25388 - Posted: 08.28.2018

Inga Vesper The executive director of the European Union’s ambitious — but contentious — Human Brain Project (HBP) has left his post after a disagreement with the institution that coordinates the initiative. The 10-year, €1-billion (US$1.1-billion) project aims to simulate the human brain using computers, and is a flagship science initiative of the EU. In a joint statement on 16 August, Chris Ebell and the HBP’s coordinating institution, the Swiss Federal Institute of Technology in Lausanne, said that they had decided to “separate by common agreement” following “differences of opinion on governance and on strategic orientations”. Ebell became director of the project in 2015, after the HBP disbanded its small executive committee in favour of a 22-member governing board. The HBP, which involves more than 100 partner institutions, had after its inception in 2013 been criticized by some neuroscientists for its scientific direction, its complicated structure and the lack of transparency surrounding its funding decisions. doi: 10.1038/d41586-018-06020-0 © 2018 Springer Nature Limited

Keyword: Brain imaging
Link ID: 25360 - Posted: 08.22.2018

James R. Howe VI In May 2007, Wim Hof went on a short hike in well-worn summer clothes, a pair of shorts and open-toed sandals. But it may have been a poor choice: his foot started to hurt and he had to turn back after four and a half miles. There are two crucial details to this story: Hof began his hike at Base Camp on Mount Everest, and the pain in his foot was caused by severe frostbite. He had reason to think he could withstand the extreme conditions; Wim Hof is also known as “The Iceman,” holder of 26 world records and one of the most successful extreme athletes of all time. He attributes his success to a breathing method that he thinks exploits his “reptilian brain,” helping him acquire a superhuman tolerance to punishing cold. According to some, tricks like these fool the lizard part of your brain – the more primitive, unconscious mind – and can be used to make us vulnerable to marketing, lose us money, or maybe even elect Donald Trump. Paul MacLean first proposed the idea of the “lizard brain” in 1957 as part of his triune brain concept, theorizing that the human brain supposedly consists of three sections, nested based on their evolutionary age. He believed the neocortex, which he thought arose in primates, is the largest, outermost, and newest part of the human brain: It houses our conscious mind and handles learning, language, and abstract thought. MacLean thought the older, deeper limbic system – which mediates emotion and motivation – began in mammals. Finally, he traced the brainstem and basal ganglia back to primordial reptiles, theorizing that they controlled our reflexes, as well as our four major instincts: to fight, flee, feed, and fornicate.

Keyword: Evolution
Link ID: 25356 - Posted: 08.21.2018

By Andrew R. Calderon In 1978, Thomas Barefoot was convicted of killing a police officer in Texas. During the sentencing phase of his trial, the prosecution called two psychiatrists to testify about Barefoot’s “future dangerousness,” a capital-sentencing requirement that asked the jury to determine if the defendant posed a threat to society. The psychiatrists declared Barefoot a “criminal psychopath,” and warned that whether he was inside or outside a prison, there was a “one hundred percent and absolute chance” that he would commit future acts of violence that would “constitute a continuing threat to society.” Informed by these clinical predictions, the jury sentenced Barefoot to death. Although such psychiatric forecasting is less common now in capital cases, a battery of risk assessment tools has since been developed that aims to help courts determine appropriate sentencing, probation and parole. Many of these risk assessments use algorithms to weigh personal, psychological, historical and environmental factors to make predictions of future behavior. But it is an imperfect science, beset by accusations of racial bias and false positives. Now a group of neuroscientists at the University of New Mexico propose to use brain imaging technology to improve risk assessments. Kent Kiehl, a professor of psychology, neuroscience and the law at the University of New Mexico, said that by measuring brain structure and activity they might better predict the probability an individual will offend again.

Keyword: Aggression; Brain imaging
Link ID: 25339 - Posted: 08.16.2018

by Dr. Francis Collins Though our thoughts can wander one moment and race rapidly forward the next, the brain itself is often considered to be motionless inside the skull. But that’s actually not correct. When the heart beats, the pumping force reverberates throughout the body and gently pulsates the brain. What’s been tricky is capturing these pulsations with existing brain imaging technologies. Recently, NIH-funded researchers developed a video-based approach to magnetic resonance imaging (MRI) that can record these subtle movements [1]. Their method, called phase-based amplified MRI (aMRI), magnifies those tiny movements, making them more visible and quantifiable. The latest aMRI method, developed by a team including Itamar Terem at Stanford University, Palo Alto, CA, and Mehmet Kurt at Stevens Institute of Technology, Hoboken, NJ. It builds upon an earlier method developed by Samantha Holdsworth at New Zealand’s University of Auckland and Stanford’s Mahdi Salmani Rahimi [2]. In the video, a traditional series of brain scans captured using standard MRI (left) make the brain appear mostly motionless. But a second series of scans captured using the new technique (right) shows the brain pulsating with each and every heartbeat. As described in the journal Magnetic Resonance in Medicine, the team started by measuring the pulse of a healthy person. They synchronized the pulse with MRI images of the person’s brain, stitching the scans together to create a sequential video. Their new MRI approach then relies on a special algorithm developed by another group to magnify the subtle changes.

Keyword: Brain imaging
Link ID: 25311 - Posted: 08.10.2018

A handful of Alzheimer's patients signed up for a bold experiment: they let scientists beam sound waves into the brain to temporarily jiggle an opening in its protective shield. The so-called blood-brain barrier prevents germs and other damaging substances from leaching in through the bloodstream — but it can block drugs for Alzheimer's, brain tumours and other neurological diseases. Canadian researchers on Wednesday reported early hints that technology called focused ultrasound can safely poke holes in that barrier — holes that quickly sealed back up. It's a step toward one day using the non-invasive device to push brain treatments through. "It's been a major goal of neuroscience for decades, this idea of a safe and reversible and precise way of breaching the blood-brain barrier," said Dr. Nir Lipsman, a neurosurgeon at Toronto's Sunnybrook Health Sciences Centre who led the study. "It's exciting." The findings were presented at the Alzheimer's Association international conference in Chicago and published Wednesday in Nature Communications. This first-step research, conducted in just six people with mild to moderate Alzheimer's, didn't test potential therapies; its aim was to check whether patients' fragile blood vessels could withstand the breach without bleeding or other side-effects. ©2018 CBC/Radio-Canada

Keyword: Brain imaging
Link ID: 25249 - Posted: 07.26.2018

Laurel Hamers BRAINBOW Scientists have imaged the fruit fly brain in new detail. Colors highlight the paths of nerve cells that have been mapped so far. Cells with bodies close together share the same color, but not necessarily the same function. If the secret to getting the perfect photo is taking a lot of shots, then one lucky fruit fly is the subject of a masterpiece. Using high-speed electron microscopy, scientists took 21 million nanoscale-resolution images of the brain of Drosophila melanogaster to capture every one of the 100,000 nerve cells that it contains. It’s the first time the entire fruit fly brain has been imaged in this much detail, researchers report online July 19 in Cell. Experimental neurobiologists can now use the rich dataset as a roadmap to figure out which neurons talk to each other in the fly’s brain, says study coauthor Davi Bock, a neurobiologist at Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va. The rainbow image shown here captures the progress on that mapping so far. Despite the complex tangle of neural connections pictured, the mapping is far from complete, Bock says. Neurons with cell bodies close to each other are colored the same hue, to demonstrate how neurons born in the same place in the poppy seed–sized brain tend to send their spidery tendrils out in the same direction, too. |© Society for Science & the Public 2000 - 2018. All rights reserved.

Keyword: Brain imaging
Link ID: 25231 - Posted: 07.20.2018

Tom Goldman CTE has been part of the national lexicon in the U.S. since the 2015 movie Concussion dramatized the discovery of this degenerative brain disease among football players. Chronic traumatic encephalopathy is found among people who've had head injuries. Though not everyone with head trauma develops CTE, the group that's come to be most associated with it is football players, whose brains can be routinely jarred by hard hits. The disease has been linked to depression, dementia and even suicide among those who play the game. But the Journal of Alzheimer's Disease published a study Tuesday that helps broaden the understanding of who is potentially affected by CTE to include military personnel. And, perhaps more significantly, the study represents a step forward in developing a test for the disease in the living. Right now, accurately diagnosing CTE requires the close study of brain tissue during autopsy, to identify the telltale abnormal proteins that kill brain cells. And this is a key reason why knowledge about CTE — who gets it, how widespread it is and the development of treatments — has lagged. "You've really got to have a living diagnosis scan in order to make much headway on understanding the disease," says Dr. Julian Bailes, a neurosurgeon at the Chicago area's NorthShore University HealthSystem, and one of the study's authors. That diagnostic scan is what researchers have gotten close to in this case. © 2018 npr

Keyword: Brain Injury/Concussion; Brain imaging
Link ID: 25227 - Posted: 07.19.2018

Catherine Offord Researchers at Caltech have designed a noninvasive method to control specific neural circuits in the mouse brain. The technique, published earlier this week (July 9) in Nature Biomedical Engineering, combines ultrasound waves with genetic engineering and the administration of designer compounds to selectively activate or inhibit neurons. Although currently only tested in mice, the approach could offer a novel way to administer therapy to regions of the human brain that are difficult to access using surgery. “By using sound waves and known genetic techniques, we can, for the first time, noninvasively control specific brain regions and cell types as well as the timing of when neurons are switched on or off,” study coauthor Mikhail Shapiro says in a statement. While several emerging methods in neuroscience allow researchers to manipulate brain circuits, most “require invasive techniques such as stereotaxic surgery, which can damage tissue and initiate a long-lasting immune response,” note neuroscientists Caroline Menard and Scott Russo of Quebec City’s Université Laval and the Icahn School of Medicine at Mount Sinai, respectively, in an accompanying News and Views article. “Also, conventional pharmacological approaches lack the spatial, temporal and cell-type specificity required to treat the brain, and can lead to deleterious side effects.” © 1986 - 2018 The Scientist.

Keyword: Brain imaging
Link ID: 25218 - Posted: 07.17.2018

By Nicola Twilley On a foggy February morning in Oxford, England, I arrived at the John Radcliffe Hospital, a shiplike nineteen-seventies complex moored on a hill east of the city center, for the express purpose of being hurt. I had an appointment with a scientist named Irene Tracey, a brisk woman in her early fifties who directs Oxford University’s Nuffield Department of Clinical Neurosciences and has become known as the Queen of Pain. “We might have a problem with you being a ginger,” she warned when we met. Redheads typically perceive pain differently from those with other hair colors; many also flinch at the use of the G-word. “I’m sorry, a lovely auburn,” she quickly said, while a doctoral student used a ruler and a purple Sharpie to draw the outline of a one-inch square on my right shin. Wearing thick rubber gloves, the student squeezed a dollop of pale-orange cream into the center of the square and delicately spread it to the edges, as if frosting a cake. The cream contained capsaicin, the chemical responsible for the burn of chili peppers. “We love capsaicin,” Tracey said. “It does two really nice things: it ramps up gradually to become quite intense, and it activates receptors in your skin that we know a lot about.” Thus anointed, I signed my disclaimer forms and was strapped into the scanning bed of a magnetic-resonance-imaging (MRI) machine. The machine was a 7-Tesla MRI, of which there are fewer than a hundred in the world. The magnetic field it generates (teslas are a unit of magnetic strength) is more than four times as powerful as that of the average hospital MRI machine, resulting in images of much greater detail. As the cryogenic units responsible for cooling the machine’s superconducting magnet clicked on and off in a syncopated rhythm, the imaging technician warned me that, once he slid me inside, I might feel dizzy, see flashing lights, or experience a metallic taste in my mouth. “I always feel like I’m turning a corner,” Tracey said. She explained that the magnetic field would instantly pull the proton in each of the octillions of hydrogen atoms in my body into alignment. Then she vanished into a control room, where a bank of screens would allow her to watch my brain as it experienced pain. © 2018 Condé Nast.

Keyword: Pain & Touch; Brain imaging
Link ID: 25145 - Posted: 06.26.2018

Paul Biegler explains. Mind-reading machines are now real, prising open yet another Pandora’s box for ethicists. As usual, there are promises of benefit and warnings of grave peril. The bright side was front and centre at the Society for Neuroscience annual meeting in Washington DC in November 2017. It was part of a research presentation led by Omid Sani from the University of Southern California. Sani and his colleagues studied six people with epilepsy who had electrodes inserted into their brains to measure detailed electrical patterns. It is a common technique to help neurosurgeons find where seizures start. The study asked patients, who can be alert during the procedure, to report their mood during scanning. That allowed the researchers to link the patients’ moods with their brainwave readings. Using sophisticated algorithms, the team claimed to predict patients’ feelings from their brainwaves alone. That could drive a big shift in the treatment of mental illness, say researchers. Deep brain stimulation (DBS), where electrodes implanted in the brain give circuits a regular zap, has been successful in Parkinson’s disease. It is also being trialled in depression; but the results, according to a 2017 report in Lancet Psychiatry, are patchy. Sani and colleagues suggest their discovery could bump up that success rate. A portable brain decoder may be available within a generation.

Keyword: Brain imaging
Link ID: 25136 - Posted: 06.25.2018