Chapter 2. Functional Neuroanatomy: The Nervous System and Behavior

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Laura Sanders A conscious brain hums with elaborate, interwoven signals, a study finds. Scientists uncovered that new signature of consciousness by analyzing brain activity of healthy people and of people who were not aware of their surroundings. The result, published online February 6 in Science Advances, makes headway on a tough problem: how to accurately measure awareness in patients who can’t communicate. Other methods for measuring consciousness have been proposed, but because of its size and design, the new study was able to find a particularly strong signal. Conducted by an international team of researchers spanning four countries, the effort “produced clear, reliable results that are directly relevant to the clinical neuroscience of consciousness,” says cognitive neuroscientist Michael Pitts of Reed College in Portland, Ore. Consciousness — and how the brain creates it — is a squishy concept. It slips away when we sleep, and can be distorted by drugs or lost in accidents. Though scientists have proposed many biological explanations for how our brains create consciousness, a full definition still eludes scientists. By finding a clear brain signature of awareness, the new work “bring us closer to understanding what consciousness is,” says study coauthor Jacobo Sitt of INSERM in Paris. © Society for Science & the Public 2000 - 2019.

Keyword: Consciousness; Brain imaging
Link ID: 25943 - Posted: 02.09.2019

Ruth Williams The brains of people in vegetative, partially conscious, or fully conscious states have differing profiles of activity as revealed by functional magnetic resonance imaging (fMRI), according to a report today (February 6) in Science Advances. The results of the study indicate that, compared with patients lacking consciousness, the brains of healthy individuals exhibit highly dynamic and complex connectivity. “This new study provides a substantial advance in characterizing the ‘fingerprints’ of consciousness in the brain” Anil Seth, a neuroscientist at the University of Sussex, UK, who was not involved in the project, writes in an email to The Scientist. “It opens new doors to determining conscious states—or their absence—in a range of different conditions.” A person can lose consciousness temporarily, such as during sleep or anesthesia, or more permanently as is the case with certain brain injuries. But while unconsciousness manifests behaviorally as a failure to respond to stimuli, such behavior is not necessarily the result of unconsciousness. Some seemingly unresponsive patients, for example, can display brain activities similar to those of fully conscious individuals when asked to imagine performing a physical task such as playing tennis. Such a mental response in the absence of physical feedback is a condition known as cognitive-motor dissociation. Researchers are therefore attempting to build a better picture of what is happening in the human brain during consciousness and unconsciousness. In some studies, electroencephalography (EEG) recordings of the brain’s electrical activities during sleep, under anesthesia, or after brain injury have revealed patterns of brain waves associated with consciousness. But, says Jacobo Sitt of the Institute of Brain and Spinal Cord in Paris, such measurements do not provide good spatial information about brain activity. With fMRI, on the other hand, “we know where the activity is coming from.” © 1986 - 2019 The Scientist.

Keyword: Consciousness; Brain imaging
Link ID: 25941 - Posted: 02.08.2019

Jon Hamilton Women tend to have more youthful brains than their male counterparts — at least when it comes to metabolism. While age reduces the metabolism of all brains, women retain a higher rate throughout the lifespan, researchers reported Monday in the journal Proceedings of the National Academy of Sciences. "Females had a younger brain age relative to males," says Dr. Manu Goyal, an assistant professor of radiology and neurology at Washington University School of Medicine in St. Louis. And that may mean women are better equipped to learn and be creative in later life, he says. The finding is "great news for many women," says Roberta Diaz Brinton, who wasn't connected with the study and directs the Center for Innovation in Brain Science at the University of Arizona Health Sciences. But she cautions that even though women's brain metabolism is higher overall, some women's brains experience a dramatic metabolic decline around menopause, leaving them vulnerable to Alzheimer's. The study came after Goyal and a team of researchers studied the brain scans of 205 people whose ages ranged from 20 to 82. Positron emission tomography scans of these people assessed metabolism by measuring how much oxygen and glucose was being used at many different locations in the brain. The team initially hoped to use the metabolic information to predict a person's age. So they had a computer study how metabolism changed in both men and women. © 2019 npr

Keyword: Sexual Behavior; Brain imaging
Link ID: 25933 - Posted: 02.05.2019

A study has shed light on the neurocomputational contributions to the development of post-traumatic stress disorder (PTSD) in combat veterans. The findings, published in Nature Neuroscience, revealed distinct patterns for how the brain and body respond to learning danger and safety depending on the severity of PTSD symptoms. These findings could help explain why symptoms of PTSD can be severe for some people but not others. The study was funded in part by the National Institute of Mental Health, part of the National Institutes of Health. “Researchers have thought that the experience of PTSD, in many ways, is an overlearned response to survive a threatening experience,” said Susan Borja, Ph.D., chief of the NIMH Dimensional Traumatic Stress Research Program. “This study clarifies that those who have the most severe symptoms may appear behaviorally similar to those with less severe symptoms, but are responding to cues in subtly different, but profound, ways.” PTSD is a disorder that can sometimes develop after exposure to a traumatic event. People with PTSD may experience intrusive and frightening thoughts and memories of the event, experience sleep problems, feel detached or numb, or may be easily startled. While almost half of all U.S. adults will experience a traumatic event in their life, most do not develop PTSD. One theory explaining why some symptoms of PTSD develop suggests that during a traumatic event, a person may learn to view the people, locations, and objects that are present as being dangerous if they become associated with the threatening situation. While some of these things may be dangerous, some are safe. PTSD symptoms result when these safe stimuli continue to trigger fearful and defensive responses long after the trauma has occurred.

Keyword: Stress; Brain imaging
Link ID: 25912 - Posted: 01.29.2019

Ian Sample Science editor A group of volunteers who took a trip in the name of science have helped researchers uncover how LSD messes with activity in the brain to induce an altered state of consciousness. Brain scans of individuals high on the drug revealed that the chemical allows parts of the cortex to become flooded with signals that are normally filtered out to prevent information overload. The drug allowed more information to flow from the thalamus, a kind of neural gatekeeper, to a region called the posterior cingulate cortex, and it stemmed the flow of information to another part known as the temporal cortex. This disruption in communication may underpin some of the wacky effects reported by LSD users, from feelings of bliss and being at one with the universe to hallucinations and what scientists in the field refer to as “ego dissolution”, where one’s sense of self disintegrates. For the study, the researchers invited 25 healthy participants into the lab to be scanned under the influence of LSD and, on another occasion, after taking a placebo. They were shown around the scanner beforehand to ensure they felt comfortable going inside when the drug took hold. Had the machine suddenly taken on a threatening demeanour, the scans might not have come out so well. The scientists wanted to test a hypothesis first put forward more than a decade ago. It states LSD causes the thalamus to stop filtering information it relays to other parts of the brain. It is the breakdown of this filter that gives rise to the weird effects the drug induces, or so the thinking goes. © 2019 Guardian News and Media Limited

Keyword: Drug Abuse; Brain imaging
Link ID: 25910 - Posted: 01.29.2019

By David Grossman The brain remains famously remains one of the most mysterious parts of the human body. The challenges of neuroscience are among the most daunting in the medical field. Expansion microscopy is a crucial element of that study, a chemical technique that expands a small specimen to make it more observable at the molecular level. A new technique allows scientists to expand microscopy so instead of focusing a single sell, it can explore full neural circuits, at a speed around 1,000 times faster than before. A struggle in studying live cells is watching them without altering their actions. Scientists work around this problem by using thin sheets of light to illuminate cells with a piece of complex technology called a lattice light sheet microscope. By combining this microscope with expansion microscopy, scientists at the Howard Hughes Medical Institute (HHMI) were able to expand the possibility of how they could study insect brains. “I thought they were full of it,” says Eric Betzig, now an HHMI investigator at the University of California, Berkeley, in a press statement. "They" refers to Ruixuan Gao and Shoh Asano of MIT, who wanted to use Betzig's lab to attempt their combining of the two practices. While a complex procedure involving high-end scientific equipment, at its heart “the idea does sound a bit crude,” Gao says. “We’re stretching tissues apart." When the experiment was over, Betzig says, “I couldn’t believe the quality of the data I was seeing. You could have knocked me over with a feather.” ©2019 Hearst Magazine Media, Inc

Keyword: Brain imaging
Link ID: 25886 - Posted: 01.21.2019

By Diana Kwon o For the longest time the cerebellum, a dense, fist-size formation located at the base of the brain, never got much respect from neuroscientists. For about two centuries the scientific community believed the cerebellum (Latin for “little brain”), which contains approximately half of the brain’s neurons, was dedicated solely to the control of movement. In recent decades, however, the tide has started to turn, as researchers have revealed details of the structure’s role in cognition, emotional processing and social behavior. The longstanding interest in the cerebellum can be seen in the work of French physiologist Marie Jean Pierre Flourens—(1794–1867). Flourens removed the cerebella of pigeons and found the birds became unbalanced, although they could still move. Based on these observations, he concluded the cerebellum was responsible for coordinating movements. “[This] set the dogma that the cerebellum was involved in motor coordination,” says Kamran Khodakhah, a neuroscientist at Albert Einstein College of Medicine, adding: “For many years, we ignored the signs that suggested it was involved in other things.” One of the strongest pieces of evidence for the cerebellum’s broader repertoire emerged around two decades ago, when Jeremy Schmahmann, a neurologist at Massachusetts General Hospital, described cerebellar cognitive affective syndrome after discovering behavioral changes such as impairments in abstract reasoning and regulating emotion in individuals whose cerebella had been damaged. Since then this line of study has expanded. There has been human neuroimaging work showing the cerebellum is involved in cognitive processing and emotional control—and investigations in animals have revealed, among other things, that the structure is important for the normal development of social and cognitive capacities. Researchers have also linked altered cerebellar function to addiction, autism and schizophrenia.

Keyword: Drug Abuse; Emotions
Link ID: 25880 - Posted: 01.19.2019

Rachel Zamzow Patterns of brain activity in people with autism are unusually consistent over seconds—and even years, two new studies suggest. One study shows that patterns of connectivity remain stable in autistic adolescents, whereas they tend to change and specialize in controls. The other study found that connections remain fixed longer in people with autism than in controls. Both focused on so-called “functional connectivity,” the extent to which the activity of pairs of brain areas is synchronized. Together, the studies may help untangle seemingly contradictory findings on connectivity in autism: reports of both underconnectivity and overconnectivity in the brain. “Maybe the primary abnormality isn’t just that things are too weakly or strongly connected, that it has more to do with the timing of brain connections,” says Jeff Anderson, professor of radiology at the University of Utah, who led the second study. The studies also highlight the importance of measuring brain activity over varying time periods and at different ages. Researchers who home in on a single age may overlook differences that appear over time, says Mirella Dapretto, professor of psychiatry and biobehavioral sciences at the University of California, Los Angeles, and lead researcher on the adolescent study. “You miss some of the bigger picture.” Studying brain activity over time provides a rare window into the development of connectivity. © 1986 - 2019 The Scientist

Keyword: Autism; Development of the Brain
Link ID: 25879 - Posted: 01.19.2019

Laura Sanders Using laser light, ballooning tissue and innovative genetic tricks, scientists are starting to force brains to give up their secrets. By mixing and matching powerful advances in microscopy and cell biology, researchers have imaged intricate details of individual nerve cells in fruit flies and mice, and even controlled small groups of nerve cells in living mice. The techniques, published in two new studies, represent big steps forward for understanding how the brain operates, says molecular neuroscientist Hongkui Zeng of the Allen Institute for Brain Science in Seattle. “Without this kind of technology, we were only able to look at the soup level,” in which diverse nerve cells, or neurons, are grouped and analyzed together, she says. But the new studies show that nerve cells can be studied individually. That zoomed-in approach will begin to uncover the tremendous diversity that’s known to exist among cells, says Zeng, who was not involved in the research. “That is where the field is going. It’s very exciting to see that technologies are now enabling us to do that,” she says. These novel abilities came from multiple tools. At Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va., physicist Eric Betzig and his colleagues had developed a powerful microscope that can quickly peer deep into layers of brain tissue. Called a lattice light sheet microscope, the rig sweeps a thin sheet of laser light down through the brain, revealing cells’ structures. But like any microscope, it hits a wall when structures get really small, unable to resolve the most minute aspects of the scene. |© Society for Science & the Public 2000 - 2019.

Keyword: Brain imaging
Link ID: 25878 - Posted: 01.18.2019

By Kelly Servick For many people who are paralyzed and unable to speak, signals of what they'd like to say hide in their brains. No one has been able to decipher those signals directly. But three research teams recently made progress in turning data from electrodes surgically placed on the brain into computer-generated speech. Using computational models known as neural networks, they reconstructed words and sentences that were, in some cases, intelligible to human listeners. None of the efforts, described in papers in recent months on the preprint server bioRxiv, managed to re-create speech that people had merely imagined. Instead, the researchers monitored parts of the brain as people either read aloud, silently mouthed speech, or listened to recordings. But showing the reconstructed speech is understandable is "definitely exciting," says Stephanie Martin, a neural engineer at the University of Geneva in Switzerland who was not involved in the new projects. People who have lost the ability to speak after a stroke or disease can use their eyes or make other small movements to control a cursor or select on-screen letters. (Cosmologist Stephen Hawking tensed his cheek to trigger a switch mounted on his glasses.) But if a brain-computer interface could re-create their speech directly, they might regain much more: control over tone and inflection, for example, or the ability to interject in a fast-moving conversation. The hurdles are high. "We are trying to work out the pattern of … neurons that turn on and off at different time points, and infer the speech sound," says Nima Mesgarani, a computer scientist at Columbia University. "The mapping from one to the other is not very straightforward." How these signals translate to speech sounds varies from person to person, so computer models must be "trained" on each individual. And the models do best with extremely precise data, which requires opening the skull. © 2018 American Association for the Advancement of Science

Keyword: Language; Brain imaging
Link ID: 25837 - Posted: 01.03.2019

Fiona McMillan Your brain has worked hard in 2018, so as the year draws to a close, take a moment to appreciate not only your marvelous network of brain cells, but those found in other species, too. Below is a list of where to find some of the year’s most stunning neuroscience images that reveal the hidden world of neurons in brilliant and breathtaking detail. In order to understand how the brain works, neuroscientists need to take a close look at how neuron networks are wired together. However this isn’t easy, after all just one cubic millimeter in the brain’s cerebral cortex contains around 50,000 neurons each making 6,000 connections with other neurons (give or take a few). Tracing a single network through this incredibly complex web is painstaking work. So, in recent years, researchers developed the Brainbow, a technique that allows individual neurons to be labelled with different fluorescent colors. Unfortunately, it still took months to trace the path of a single neuron across the mouse brain. To address this, in 2018 Takeshi Imai and his colleagues at Kyushu University, Kyoto University and the RIKEN Center for Developmental Biology in Japan took it to the next level. They developed the Tetbow, a method that produces extremely vivid colors enabling scientists to trace neuronal wiring across the whole mouse brain within a matter of days. Also, it’s really pretty. Tetbow provides colorful view of the olfactory bulbRichi Sakaguchi, Marcus N Leiwe, Takeshi Imai published in eLife Sciences under a Creative Commons CC BY 4.0 ©2019 Forbes Media LLC

Keyword: Brain imaging
Link ID: 25833 - Posted: 01.01.2019

By Kimon de Greef CAPE TOWN — A musician from South Africa had a tumor in his brain, so doctors opened a hole in his skull to remove it. But they had a crucial request: He must play his acoustic guitar during the surgery. The musician, Musa Manzini, a jazz bassist, was awake when the doctors performed the surgery last week, and video footage from the local media site News24 shows him strumming an acoustic guitar slowly as they operated. The technique, known as “awake craniotomy,” allows doctors to operate on delicate areas of the brain — like the right frontal lobe, the site of Mr. Manzini’s tumor — without causing damage. Presumably, had he hit a wrong note, it would have been an immediate signal for the surgeons to probe elsewhere. “It can be very difficult to tell the difference between the tumor and normal brain tissue,” said Dr. Basil Enicker, a specialist neurosurgeon who led the operation at Inkosi Albert Luthuli Central Hospital, in the coastal city of Durban. “Once you’re near a critical area, you can pick it up early, because he will tell you.” The surgery is not unusual. The first craniotomies date to prehistoric times, with fossil records showing that patients had holes drilled in their skulls — and survived — as early as 8,000 years ago. In the 1930s, the Canadian-American neurosurgeon Wilder Penfield pioneered modern craniotomies, which he used to treat epilepsy. The procedure has become fairly common globally since then, posing no greater technical challenge than regular brain surgery, Dr. Enicker said. But choosing patients is very important: People who cough, for example, or who cannot lie still for extended periods, are far more dangerous to operate on. © 2018 The New York Times Company

Keyword: Brain imaging; Epilepsy
Link ID: 25815 - Posted: 12.22.2018

Researchers at Howard Hughes Medical Institute (HHMI) have mapped the neuroanatomical regions of the brain of a female mosquito (Aedes aegypti). The researchers constructed the map of groups of neurons by immunostaining the mosquito’s brain for Brp, a synaptic protein, and imaged the brain with confocal microscopy. The atlas was made freely available online on January 31st. “We are trying to build the field of mosquito neurobiology,” says HHMI neurobiologist Leslie Vosshall, who led the work, in a press release. She says she hopes that the new atlas will let mosquito researchers from around the world share data and better understand which parts of the mosquito brain direct different behaviors. “Somewhere in that female brain is the drive to sense humans, fly toward humans, land on humans, and bite and drink the blood of humans,” she says. “Somewhere in that brain is where decision making, motivation, and hunger reside.” © 1986 - 2018 The Scientist

Keyword: Brain imaging
Link ID: 25811 - Posted: 12.22.2018

Michael Eisenstein In March, researchers in Japan mapped the cellular organization of the mouse brain in unprecedented detail. Systems biologist Hiroki Ueda at the RIKEN Center for Biosystems Dynamics Research in Osaka, Japan, and his team created an atlas of the mouse brain using a technique called CUBIC-X, in which they chemically labelled every cell in the brain, then rendered the organ crystal-clear while also expanding its size tenfold1. From there, they used sophisticated imaging techniques to compile a comprehensive 3D neuronal survey — of some 72 million cells in all, Ueda says. The resulting atlas reduces the brain to a compact database of cellular addresses, which the team used to explore changes in various brain regions during development. Moving forward, the atlas could drive deeper explorations of brain structures that control behaviours such as the sleep–wake cycle. CUBIC-X is just one component in a growing toolbox of such methods, which exploit readily available chemicals to provide researchers with a window not just into the brain, but into virtually every organ in the body. Some are tissue-clearing methods that make opaque tissues transparent, whereas others complement tissue clearing with a proportional size increase that exposes molecular details to conventional microscopy. The choice comes down to the scientific question. There are many ways to achieve similar ends, and users should investigate the strengths and limitations of different methods before deciding which to use. The hunger for tissue-clearing techniques originated with neuroscientists, who were frustrated by their limited ability to trace the snaking routes of axons and dendrites in the brain. © 2018 Springer Nature Publishing AG

Keyword: Brain imaging
Link ID: 25755 - Posted: 12.06.2018

By R. Douglas Fields SAN DIEGO—In the textbook explanation for how information is encoded in the brain, neurons fire a rapid burst of electrical signals in response to inputs from the senses or other stimulation. The brain responds to a light turning on in a dark room with the short bursts of nerve impulses, called spikes. Each close grouping of spikes can be compared to a digital bit, the binary off-or-on code used by computers. Neuroscientists have long known, though, about other forms of electrical activity present in the brain. In particular, rhythmic voltage fluctuations in and around neurons—oscillations that occur at the same 60-cycle-per-second frequency as AC current in the U.S.—have caught the field’s attention. These gamma waves encode information by changing a signal’s amplitude, frequency or phase (relative position of one wave to another)—and the rhythmic voltage surges influence the timing of spikes. Heated debate has arisen in recent years as to whether these analog signals, akin to the ones used to broadcast AM or FM radio, may play a role in sorting, filtering and organizing the information flows required for cognitive processes. They may be instrumental in perceiving sensory inputs, focusing attention, making and recalling memories and coupling various cognitive processes into one coherent scene. It is thought that populations of neurons that oscillate at gamma frequencies may unite the neural activity in the same way the violin section of an orchestra is coupled together in time and rhythm with the percussion section to create symphonic music. When gamma waves oscillate in resonance, “you get very rich repertoires of behaviors,” says Wolf Singer, a neuroscientist at the Ernst Strüngmann Institute in Frankfurt, Germany, who researches gamma waves. Just as your car’s dashboard will vibrate in sync with the motor vibrating at a resonant frequency, so too can separate populations of neurons couple in resonance. © 2018 Scientific American

Keyword: Brain imaging
Link ID: 25731 - Posted: 11.29.2018

Abby Olena In 2005, a 23-year-old woman in the UK was involved in a traffic accident that left her with a severe brain injury. Five months after the event, she slept and woke and could open her eyes, but she didn’t always respond to smells or touch or track things visually. In other words, she fit the clinical criteria for being in a vegetative state. In a study published in Science in 2006, a team of researchers tested her ability to imagine herself playing tennis or walking through her house while they observed activity in her brain using functional magnetic resonance imaging (fMRI). Remarkably, her brain responded with activity in the same areas of the brains of healthy people when asked to do the same, indicating that she was capable of complex cognition, despite her apparent unresponsiveness at the bedside. The findings indicated that this patient and others like her may have hidden cognitive abilities that, if found, could potentially help them communicate or improve their prognosis. Since then, researchers and clinicians around the world have used task-based neuroimaging to determine that other patients who appear unresponsive or minimally conscious can do challenging cognitive tasks. The problem is that the tests to uncover hidden consciousness can be complex to analyze, expensive to perform, and hard for all patients to access. “You would like to know if people who look like they’re unconscious are actually following what’s going on and able to carry out cognitive work, and we don’t have an efficient way of sorting those patients,” says Nicholas Schiff, a neuroscientist at Weill Cornell Medical College in New York City. © 1986 - 2018 The Scientist

Keyword: Consciousness; Brain imaging
Link ID: 25725 - Posted: 11.27.2018

By Sharon Begley, The brain surgeon began as he always does, making an incision in the scalp and gently spreading it apart to expose the skull. He then drilled a 3-inch circular opening through the bone, down to the thick, tough covering called the dura. He sliced through that, and there in the little porthole he’d made was the glistening, blood-flecked, pewter-colored brain, ready for him to approach the way spies do a foreign embassy: He bugged it. Dr. Ashesh Mehta, a neurosurgeon at the Feinstein Institute for Medical Research on Long Island, was operating on his epilepsy patient to determine the source of seizures. But the patient agreed to something more: to be part of an audacious experiment whose ultimate goal is to translate thoughts into speech. While he was in there, Mehta carefully placed a flat array of microelectrodes on the left side of the brain’s surface, over areas involved in both listening to and formulating speech. By eavesdropping on the electrical impulses that crackle through the gray matter when a person hears in the “mind’s ear” what words he intends to articulate (often so quickly it’s barely conscious), then transmitting those signals wirelessly to a computer that decodes them, the electrodes and the rest of the system hold the promise of being the first “brain-computer interface” to go beyond movement and sensation. If all goes well, it will conquer the field’s Everest: developing a brain-computer interface that could enable people with a spinal cord injury, locked-in syndrome, ALS, or other paralyzing condition to talk again. © 2018 Scientific America

Keyword: Brain imaging; Robotics
Link ID: 25708 - Posted: 11.21.2018

Sara Reardon A new technique that makes dead mice transparent and hard like plastic is giving researchers an unprecedented view of how different types of cell interact in the body. The approach lets scientists pinpoint specific tissues within an animal while scanning its entire body. The approach, called vDISCO, has already revealed surprising structural connections between organs, including hints about the extent to which brain injuries affect the immune system and nerves in other parts of the body. That could lead to better treatments for traumatic brain injury or stroke. Methods that turn entire organs clear have become popular in the past few years, because they allow scientists to study delicate internal structures without disturbing them. But removing organs from an animal’s body for analysis can make it harder to see the full effect of an injury or disease. And if scientists use older methods to make an entire mouse transparent, it can be difficult to ensure that the fluorescent markers used to label cells reach the deepest parts of an organ. The vDISCO technique overcomes many of these problems. By making the dead mice rigid and see-through, it can preserve their bodies for years, down to the structure of individual cells, says Ali Ertürk, a neuroscientist at Ludwig Maximilian University of Munich in Germany, who led the team that developed vDISCO. He presented the work this week at a meeting of the Society for Neuroscience in San Diego, California. © 2018 Springer Nature Limited.

Keyword: Brain imaging
Link ID: 25676 - Posted: 11.13.2018

Jon Hamilton Scientists may have caught a glimpse of what sadness looks like in the brain. A study of 21 people found that for most, feeling down was associated with greater communication between brain areas involved in emotion and memory, a team from the University of California, San Francisco reported Thursday in the journal Cell. "There was one network that over and over would tell us whether they were feeling happy or sad," says Vikaas Sohal, an associate professor of psychiatry at UCSF. The finding could lead to a better understanding of mood disorders, and perhaps new ways of treating them. Previous research had established that sadness and other emotions involve the amygdala, an almond-shaped mass found in each side of the brain. And there was also evidence that the hippocampus, which is associated with memory, can play a role in emotion. But Sohal and the other researchers were curious about precisely what these and other brain areas are doing when someone's mood shifts. "We really wanted to get at, you know, when you're feeling down or feeling happy, what exactly is happening in the brain at those moments," Sohal says. You can't get that information from brain scans, which don't capture changes that happen in fractions of a second. So the team studied 21 people who were in the hospital awaiting brain surgery for severe epilepsy. © 2018 npr

Keyword: Emotions; Brain imaging
Link ID: 25659 - Posted: 11.09.2018

Surgeons have tested the use of a fluorescent marker that can help them remove dangerous brain tumour cells from patients more accurately. The research was carried out on people who had suspected glioblastoma, the disease that killed British politician Dame Tessa Jowell in May, and the most common form of brain cancer. Treatment usually involves surgery to remove as much of the cancer as possible, but it can be challenging for surgeons to identify all the cancer cells while avoiding healthy brain tissue. Researchers said using the fluorescent marker helped distinguish the most aggressive cancer cells from other brain tissue and they hope this will ultimately improve patient survival. They used a compound called 5-aminolevulinic acid or 5-ALA, which the patient drinks. The compound glows pink when a light is shone on it. Previous research shows that 5-ALA accumulates in fast-growing cancer cells so it can act as a fluorescent marker of high-grade cells. The study was carried out on 99 patients with suspected high-grade gliomas – a kind of tumour –who were treated at Royal Liverpool hospital, King’s college hospital in London and Addenbrooke’s hospital in Cambridge. They were aged between 23 and 77, with an average age of 59. During their operations, surgeons reported seeing fluorescence in 85 patients and 81 of these were subsequently confirmed by pathologists to have high-grade disease. One was found to have low-grade disease and three could not be assessed. © 2018 Guardian News and Media Limited

Keyword: Brain imaging
Link ID: 25646 - Posted: 11.05.2018