Chapter 2. Cells and Structures: The Anatomy of the Nervous System

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By Tara Bahrampour A significant portion of people with mild cognitive impairment or dementia who are taking medication for Alzheimer’s may not actually have the disease, according to interim results of a major study currently underway to see how PET scans could change the nature of Alzheimer’s diagnosis and treatment. The findings, presented Wednesday at the Alzheimer’s Association International Conference in London, come from a four-year study launched in 2016 that is testing over 18,000 Medicare beneficiaries with MCI or dementia to see if their brains contain the amyloid plaques that are one of the two hallmarks of the disease. So far, the results have been dramatic. Among 4,000 people tested so far in the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) study, researchers from the Memory and Aging Center at the University of California, San Francisco found that just 54.3 percent of MCI patients and 70.5 percent of dementia patients had the plaques. A positive test for amyloid does not mean someone has Alzheimer’s, though its presence precedes the disease and increases the risk of progression. But a negative test definitively means a person does not have it. The findings could change the way doctors treat people in these hard-to-diagnose groups and save money currently being spent on inappropriate medication. “If someone had a putative diagnosis of Alzheimer’s Disease, they might be on an Alzheimer’s drug like Aricept or Namenda,” said James Hendrix, the Alzheimer Association’s director of global science initiatives who co-presented the findings. “What if they had a PET scan and it showed that they didn’t have amyloid in their brain? Their physician would take them off that drug and look for something else.” © 1996-2017 The Washington Post

Keyword: Alzheimers; Brain imaging
Link ID: 23848 - Posted: 07.19.2017

By Ryan Cross Can you imagine watching 20,000 videos, 16 minutes apiece, of fruit flies walking, grooming, and chasing mates? Fortunately, you don’t have to, because scientists have designed a computer program that can do it faster. Aided by artificial intelligence, researchers have made 100 billion annotations of behavior from 400,000 flies to create a collection of maps linking fly mannerisms to their corresponding brain regions. Experts say the work is a significant step toward understanding how both simple and complex behaviors can be tied to specific circuits in the brain. “The scale of the study is unprecedented,” says Thomas Serre, a computer vision expert and computational neuroscientist at Brown University. “This is going to be a huge and valuable tool for the community,” adds Bing Zhang, a fly neurobiologist at the University of Missouri in Columbia. “I am sure that follow-up studies will show this is a gold mine.” At a mere 100,000 neurons—compared with our 86 billion—the small size of the fly brain makes it a good place to pick apart the inner workings of neurobiology. Yet scientists are still far from being able to understand a fly’s every move. To conduct the new research, computer scientist Kristin Branson of the Howard Hughes Medical Institute in Ashburn, Virginia, and colleagues acquired 2204 different genetically modified fruit fly strains (Drosophila melanogaster). Each enables the researchers to control different, but sometimes overlapping, subsets of the brain by simply raising the temperature to activate the neurons. © 2017 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 23834 - Posted: 07.14.2017

Fergus Walsh Medical correspondent The world's most detailed scan of the brain's internal wiring has been produced by scientists at Cardiff University. The MRI machine reveals the fibres which carry all the brain's thought processes. It's been done in Cardiff, Nottingham, Cambridge and Stockport, as well as London England and London Ontario. Doctors hope it will help increase understanding of a range of neurological disorders and could be used instead of invasive biopsies. I volunteered for the project - not the first time my brain has been scanned. Computer games In 2006, it was a particular honour to be scanned by the late Sir Peter Mansfield, who shared a Nobel prize for his work on developing Magnetic Resonance Imaging, one of the most important breakthroughs in medicine. He scanned me using Nottingham University's powerful new 7 Tesla scanner. When we looked at the crisp, high resolution images, he told me: "I'm a physicist, so don't ask me to tell you to whether there's anything amiss with your brain - you'd need a neurologist for that." I was the first UK Biobank volunteer to have their brain and other organs imaged as part of the world's biggest scanning project. More recently, I had my brain scanned while playing computer games, as part of research into the effects of sleep deprivation on cognition. So my visit to the Cardiff University's Brain Research Imaging Centre (CUBRIC) held no particular concerns. The scan took around 45 minutes and seemed unremarkable. A neurologist was on hand to reassure me my brain looked normal. My family quipped that they were happy that a brain had been found inside my thick skull. But nothing could have prepared me for the spectacular images produced by the team at Cardiff, along with engineers from Siemens in Germany and the United States. © 2017 BBC.

Keyword: Brain imaging
Link ID: 23801 - Posted: 07.04.2017

By Debra W. Soh If there was a way of telling who in our society is sexually attracted to children, are we entitled to know? A recent study from Georg-August-University Göttingen in Germany suggests that we may need to grapple with this question. Phallometric testing, also known as penile plethysmography, is considered the gold standard in measuring male sexual arousal, and particularly, deviant sexual interests such as pedophilia, which is the sexual interest in prepubescent children, roughly aged 3 to 10. The test involves measuring the volume of blood in the test-taker’s penis using an airtight glass tube (or conversely, measuring penile circumference with a mercury strain gauge) while he is presented with a series of images of children and adults, and audio stories describing a corresponding sexual encounter. Phallometry is commonly used in forensic settings to assess the sexual interests of sex offenders, in order to determine their risk of re-offending. As one can imagine, sex offenders tend not to be forthright about their sexual preferences, which makes phallometry all the more important. It has, however, been criticized because the test can become easier for individuals to fool with each successive assessment. Brain scanning using fMRI holds much promise as a diagnostic tool in evaluating sexual interests, as research has documented a reliable network of brain regions involved in sexual arousal. The current study took this another step by testing whether brain functional activation could be used to infer what someone finds sexually interesting without them knowing. © 2017 Scientific American,

Keyword: Sexual Behavior; Brain imaging
Link ID: 23783 - Posted: 06.28.2017

By Diana Kwon Glioblastomas, highly aggressive malignant brain tumors, have a high propensity for recurrence and are associated with low survival rates. Even when surgeons remove these tumors, deeply infiltrated cancer cells often remain and contribute to relapse. By harnessing neutrophils, a critical player in the innate immune response, scientists have devised a way to deliver drugs to kill these residual cells, according to a study published today (June 19) in Nature Nanotechnology. Neutrophils, the most common type of white blood cell, home in to areas of injury and inflammation to fight infections. Prior studies in both animals and humans have reported that neutrophils can cross the blood-brain barrier, and although these cells are not typically attracted to glioblastomas, they are recruited at sites of tumor removal in response to post-operative inflammation. To take advantage of the characteristics of these innate immune cells, researchers at China Pharmaceutical University encased paclitaxel, a traditional chemotherapy drug, with lipids. These liposome capsules were loaded into neutrophils and injected in the blood of three mouse models of glioblastoma. When the treatment was applied following surgical removal of the main tumor mass, the neutrophil-carrying drugs were able to cross the blood-brain barrier, destroy residual cancer cells, and slow the growth of new tumors. Overall, mice receiving treatment lived significantly longer than controls. © 1986-2017 The Scientist

Keyword: Brain imaging; Neuroimmunology
Link ID: 23756 - Posted: 06.21.2017

Kathryn Hess can’t tell the difference between a coffee mug and a bagel. That’s the old joke anyway. Hess, a researcher at the Swiss Federal Institute of Technology, is one of the world’s leading thinkers in the field of algebraic topology—in super simplified terms, the mathematics of rubbery shapes. It uses algebra to attack the following question: If given two geometric objects, can you deform one to another without making any cuts? The answer, when it comes to bagels and coffee mugs, is yes, yes you can. (They only have one hole apiece, lol.) If that all sounds annoyingly abstract, well, it kind of is. Algebraic topologists have lived almost exclusively in multidimensional universes of their own calculation for decades. It’s only recently that pure mathematicians like Hess have begun applying their way of seeing the world to more applied, real-world problems. If you can call understanding the dynamics of a virtual rat brain a real-world problem. In a multimillion-dollar supercomputer in a building on the same campus where Hess has spent 25 years stretching and shrinking geometric objects in her mind, lives one of the most detailed digital reconstructions of brain tissue ever built. Representing 55 distinct types of neurons and 36 million synapses all firing in a space the size of pinhead, the simulation is the brainchild of Henry Markram. Markram and Hess met through a mutual researcher friend 12 years ago, right around the time Markram was launching Blue Brain—the Swiss institute’s ambitious bid to build a complete, simulated brain, starting with the rat. Over the next decade, as Markram began feeding terabytes of data into an IBM supercomputer and reconstructing a collection of neurons in the sensory cortex, he and Hess continued to meet and discuss how they might use her specialized knowledge to understand what he was creating. “It became clearer and clearer algebraic topology could help you see things you just can’t see with flat mathematics,” says Markram. But Hess didn’t officially join the project until 2015, when it met (and some would say failed) its first big public test.

Keyword: Brain imaging
Link ID: 23741 - Posted: 06.14.2017

By Hannah Osborne Scientists studying the brain have discovered that the organ operates on up to 11 different dimensions, creating multiverse-like structures that are “a world we had never imagined.” By using an advanced mathematical system, researchers were able to uncover architectural structures that appears when the brain has to process information, before they disintegrate into nothing. Their findings, published in the journal Frontiers in Computational Neuroscience, reveals the hugely complicated processes involved in the creation of neural structures, potentially helping explain why the brain is so difficult to understand and tying together its structure with its function. The team, led by scientists at the EPFL, Switzerland, were carrying out research as part of the Blue Brain Project—an initiative to create a biologically detailed reconstruction of the human brain. Working initially on rodent brains, the team used supercomputer simulations to study the complex interactions within different regions. In the latest study, researchers honed in on the neural network structures within the brain using algebraic topology—a system used to describe networks with constantly changing spaces and structures. This is the first time this branch of math has been applied to neuroscience. "Algebraic topology is like a telescope and microscope at the same time. It can zoom into networks to find hidden structures—the trees in the forest—and see the empty spaces—the clearings—all at the same time," study author Kathryn Hess said in a statement.

Keyword: Brain imaging
Link ID: 23739 - Posted: 06.14.2017

By Ashley Yeager A database of electron microscopy images reveals the connections of the entire female fruit fly brain. In this image, types of Kenyon cells (KC) in the mushroom body main calyx are labeled by color: αβc-KCs are green, αβs-KCs are yellowish brown, and gamma-KCs are blue. The white arrows point to visible presynaptic release sites.ZHENG ET AL. 2017A 21-million-image dataset of the female fruit fly brain is offering an unprecedented view of the cells and their connections that underlie the animal’s behavior. The full-brain survey, taken by electron microscopy, allowed researchers to describe all of the neural inputs into a region of the fly’s brain linked to learning, examine how tightly neurons are clustered in the area, and identify a new cell type. “This is the biggest whole brain imaged at high resolution,” Davi Bock of the Janelia Research Campus in Ashburn, VA, tells The Scientist. He and his colleagues published a preprint of their results on bioRxiv this month (May 22). Past studies have produced electron microscopy images with resolution high enough to reveal the wiring of the entire brain of smaller organisms, such as a nematode or a fruit fly larva, or sections from larger animals, including parts of the fly brain or a cat’s thalamus. Imaging the complete fruit fly brain “is nearly two orders of magnitude larger than the next-largest complete brain imaged at sufficient resolution to trace synaptic connectivity,” Bock and colleagues wrote in their report. © 1986-2017 The Scientist

Keyword: Brain imaging
Link ID: 23696 - Posted: 06.02.2017

By Alex Hickson This totally unique mash-up between neuroscience and art shows the stunningly complex beauty of the human brain. Your brain is terrifyingly complicated and is made up of approximately 86 billion neurons which work together as a biological machine to create who you are. But it takes some real cranium contortion to get your head around what those billions of signals and connected web of cells look like. Artist and neuroscientist Dr Greg Dunn combined talents with artist and physicist Dr Brian Edwards to produce this unprecedented work of wonder. But the shimmering never-before-achieved works of art are not as they appear. They are not brain scans but have been painstakingly created using a combination of neuroscience research, hand drawing, computer simulations and all finished off with glistening gold leaf. Both the artists say they wanted the work to remind people that the most marvelous machine in the universe is in our own heads and hope that the brilliant display will reveal the root of our shared humanity. ‘Self Reflected was created not to simplify the brain’s functionality for easier consumption, but to depict it as close to its native complexity as possible so that the viewer comes away with a visceral and emotional understanding of its beauty,’ they write.

Keyword: Brain imaging
Link ID: 23673 - Posted: 05.29.2017

Claude Messier, Alexandria Béland-Millar, The short answer is yes: certain brain regions do indeed consume more energy when engaged in particular tasks. Yet the specific regions involved and the amount of energy each consumes depend on the person’s experiences as well as each brain’s individual properties. Before we delve into the answer, it is important to understand how we measure a brain’s energy expenditure. Picture the colorful brain images researchers use to display neural activity. The colors typically represent the amount of oxygen or glucose various brain regions use during a task. Our brain is always active on some level—even when we are not engaged in a task—but it requires more energy to accomplish something that demands concentration such as moving, seeing or thinking. A simple example is that our primary visual cortex lights up more in brain scans—consuming more energy—when our eyes are open than when they are closed. Similarly, our primary motor cortex uses more energy if we move our hands than if we keep them still. Say you are learning a new skill—how to juggle or speak Spanish. Neuroscientists have made the fascinating observation that when we do something completely novel, a broad range of brain areas becomes active. As we become more skilled at the task, however, our brain becomes more focused: we require only the essential brain regions and need increasingly less energy to perform that task. Once we have mastered a skill—we become fluent in Spanish—only the brain areas directly involved remain active. Thus, learning a new skill requires more brainpower than a well-practiced activity. © 2017 Scientific American

Keyword: Brain imaging
Link ID: 23647 - Posted: 05.23.2017

Ian Sample Science editor A landmark project to map the wiring of the human brain from womb to birth has released thousands of images that will help scientists unravel how conditions such as autism, cerebral palsy and attention deficit disorders arise in the brain. The first tranche of images come from 40 newborn babies who were scanned in their sleep to produce stunning high-resolution pictures of early brain anatomy and the intricate neural wiring that ferries some of the earliest signals around the organ. The initial batch of brain scans are intended to give researchers a first chance to analyse the data and provide feedback to the senior scientists at King’s College London, Oxford University and Imperial College London who are leading the Developing Human Connectome Project, which is funded by €15m (£12.5m) from the EU. The images show the intricate neural wiring that ferries some of the earliest signals around the brain. Hundreds of thousands more images will be released in the coming months and years. Most will come from a thousand sleeping babies, but another 500 have had their brains scanned while still in the womb. “The challenge is that you are imaging one person inside another person and both of them move,” said Jo Hajnal, professor of imaging science at King’s College London, who developed new MRI technology for the project. Taking brain scans of sleeping babies is hard enough. At the start of the project in 2013, more than 10% of the scans failed when babies woke up in the middle of the two to three hour procedure. Now the babies are fed and prepared for their scans at their mother’s side before they are carried to the scanner. To cut the odds of the babies waking, scientists tweaked the scanner software to stop it making sudden noises.

Keyword: Development of the Brain; Brain imaging
Link ID: 23599 - Posted: 05.10.2017

Shelby Putt How did humans get to be so smart, and when did this happen? To untangle this question, we need to know more about the intelligence of our human ancestors who lived 1.8 million years ago. It was at this point in time that a new type of stone tool hit the scene and the human brain nearly doubled in size. Some researchers have suggested that this more advanced technology, coupled with a bigger brain, implies a higher degree of intelligence and perhaps even the first signs of language. But all that remains from these ancient humans are fossils and stone tools. Without access to a time machine, it’s difficult to know just what cognitive features these early humans possessed, or if they were capable of language. Difficult – but not impossible. Now, thanks to cutting-edge brain imaging technology, my interdisciplinary research team is learning just how intelligent our early tool-making ancestors were. By scanning the brains of modern humans today as they make the same kinds of tools that our very distant ancestors did, we are zeroing in on what kind of brainpower is necessary to complete these tool-making tasks. The stone tools that have survived in the archaeological record can tell us something about the intelligence of the people who made them. Even our earliest human ancestors were no dummies; there is evidence for stone tools as early as 3.3 million years ago, though they were probably making tools from perishable items even earlier. © 2010–2017, The Conversation US, Inc.

Keyword: Evolution; Brain imaging
Link ID: 23594 - Posted: 05.09.2017

By Ariana Eunjung Cha Congress unveiled a bipartisan budget late Sunday that contains a number of welcome surprises for researchers who had been panicking since March, when President Trump proposed deep funding cuts for science and health. Under the deal, the National Institutes of Health will get a $2 billion boost in fiscal year 2017, as it did the previous year. Trump had proposed cutting the NIH budget by about one-fifth, or $6 billion, in a draft 2018 budget. The NIH budget continues support for key areas of research, such as precision medicine and neuroscience, that were priorities under President Barack Obama; adds funding to target diseases such as Alzheimer's and cancer; and combats emerging threats such as antibiotic-resistant infections. Here are some of the big research winners: 1) Cancer: 2) Alzheimer's: Alzheimer's is now the sixth leading cause of death in the United States, yet it remains a mystery in terms of its cause and possible treatments. Public health experts expect the number of Americans with Alzheimer's to increase dramatically in the coming years as baby boomers age into their 70s and 80s. The new budget sets aside an additional $400 million for a total of $1.39 billion for Alzheimer's research. 5) BRAIN: Another Obama-era initiative, the Brain Research Through Advancing Innovative Neurotechnologies program, seeks to create a comprehensive guide to the anatomy and functioning of the brain. The budget includes $110 million for efforts to map the human brain. © 1996-2017 The Washington Post

Keyword: Brain imaging
Link ID: 23559 - Posted: 05.02.2017

New research from the National Institutes of Health found that pairing the antidepressant amitriptyline with drugs designed to treat central nervous system diseases, enhances drug delivery to the brain by inhibiting the blood-brain barrier in rats. The blood-brain barrier serves as a natural, protective boundary, preventing most drugs from entering the brain. The research, performed in rats, appeared online April 27 in the Journal of Cerebral Blood Flow and Metabolism. Although researchers caution that more studies are needed to determine whether people will benefit from the discovery, the new finding has the potential to revolutionize treatment for a whole host of brain-centered conditions, including epilepsy, stroke,human amyotrophic lateral sclerosis (ALS), depression, and others. The results are so promising that a provisional patent application has been filed for methods of co-administration of amitriptyline with central nervous system drugs. According to Ronald Cannon, Ph.D., staff scientist at NIH’s National Institute of Environmental Health Sciences (NIEHS), the biggest obstacle to efficiently delivering drugs to the brain is a protein pump called P-glycoprotein. Located along the inner lining of brain blood vessels, P-glycoprotein directs toxins and pharmaceuticals back into the body’s circulation before they pass into the brain. To get an idea of how P-glycoprotein works, Cannon said to think of the protein as a hotel doorman, standing in front of a revolving door at a lobby entrance. A person who is not authorized to enter would get turned away, being ushered back around the revolving door and out into the street.

Keyword: Depression
Link ID: 23548 - Posted: 04.28.2017

By NICK WINGFIELD SEATTLE — Zoran Popović knows a thing or two about video games. A computer science professor at the University of Washington, Dr. Popović has worked on software algorithms that make computer-controlled characters move realistically in games like the science-fiction shooter “Destiny.” But while those games are entertainment designed to grab players by their adrenal glands, Dr. Popović’s latest creation asks players to trace lines over fuzzy images with a computer mouse. It has a slow pace with dreamy music that sounds like the ambient soundtrack inside a New Age bookstore. The point? To advance neuroscience. Since November, thousands of people have played the game, “Mozak,” which uses common tricks of the medium — points, leveling up and leader boards that publicly rank the performance of players — to crowdsource the creation of three-dimensional models of neurons. The Center for Game Science, a group at the University of Washington that Dr. Popović oversees, developed the game in collaboration with the Allen Institute for Brain Science, a nonprofit research organization founded by Paul Allen, the billionaire co-founder of Microsoft, that is seeking a better understanding of the brain. Dr. Popović had previously received wide attention in the scientific community for a puzzle game called “Foldit,” released nearly a decade ago, that harnesses the skills of players to solve riddles about the structure of proteins. The Allen Institute’s goal of cataloging the structure of neurons, the cells that transmit information throughout the nervous system, could one day help researchers understand the roots of neurodegenerative diseases like Alzheimer’s and Parkinson’s and their treatment. Neurons come in devilishly complex shapes and staggering quantities — about 100 million and 87 billion in mouse and human brains, both of which players can work on in Mozak. © 2017 The New York Times Company

Keyword: Brain imaging
Link ID: 23533 - Posted: 04.25.2017

Angelo Young Billionaire magnate Elon Musk is trying to fill the world with electric cars and solar panels while at the same time aiming to deploy reusable rockets to eventually colonize Mars. As if that weren’t enough for his plate, Musk recently announced the launch of Neuralink, a neuroscience startup seeking to create a way to interface human brains with computers. According to him, this would be part of guarding humanity against what Musk considers a threat from the rise of artificial intelligence. He envisions a lattice of electrodes implanted into the human skull that could allow people to download and upload thoughts as well as treat brain conditions such as epilepsy or bipolar disorders. Musk’s proposition seems as outlandish and unlikely as his vision for the Hyperloop rapid transport system, but like his other big ideas, there’s real science behind it. Figuring out what’s really involved in efforts to sync brains with computers was part of what inspired Adam Piore to write “The Body Builders: Inside the Science of the Engineered Human,” which was released last month by HarperCollins. Written in plain language that gives nonscientists a way to separate the science from the sensational, “The Body Builders” is a fascinating dive into what’s happening right now in bioengineering research — from brain-computer interfaces to bionic limbs — that will redefine human-machine interactions in the years to come. Piore, an award-winning journalist who has written extensively about scientific advances, spoke to Salon recently about just how close we are to being able to read one another’s thoughts through electrodes and the processing power of modern computers. © 2017 Salon Media Group, Inc.

Keyword: Brain imaging; Consciousness
Link ID: 23503 - Posted: 04.18.2017

By Ryan Cross Microscopes reveal miniscule wonders by making things seem bigger. Just imagine what scientists could see if they could also make things bigger. A new strategy to blow brains up does just that. Researchers previously invented a method for injecting a polyacrylate mesh into brain tissue, the same water-absorbing and expanding molecule that makes dirty diapers swell up. Just add water, and the tissue enlarges to 4.5 times its original size. But it wasn’t good enough to see everything. The brain is full of diminutive protrusions called dendritic spines lining the signal receiving end of a neuron. Hundreds to thousands of these nubs help strengthen or weaken an individual dendrite’s connection to other neurons in the brain. The nanoscale size of these spines makes studying them with light microscopes impossible or blurry at best, however. Now, the same group has overcome this barrier in an improved method called iterative expansion microscopy, described today in Nature Methods. Here, the tissue is expanded once, the crosslinked mesh is cleaved, and then the tissue is expanded again, resulting in roughly 20-fold enlargement. Neurons are then visualized by light-emitting molecules linked to antibodies which latch onto specified proteins. The technique has yielded detailed images showing the formation of proteins along synapses in mice, as well as detailed renderings of dendritic spines (seen in the image above) in the mouse hippocampus—a center or learning and memory in the brain. The advance could enable neuroscientists to map the many individual connections between neurons across the brain and the unique arrangement of receptors that turn brain circuits on and off. © 2017 American Association for the Advancement of Science

Keyword: Brain imaging
Link ID: 23500 - Posted: 04.18.2017

Richard A. Friedman I was doing KenKen, a math puzzle, on a plane recently when a fellow passenger asked why I bothered. I said I did it for the beauty. O.K., I’ll admit it’s a silly game: You have to make the numbers within the grid obey certain mathematical constraints, and when they do, all the pieces fit nicely together and you get this rush of harmony and order. Still, it makes me wonder what it is about mathematical thinking that is so elegant and aesthetically appealing. Is it the internal logic? The unique mix of simplicity and explanatory power? Or perhaps just its pure intellectual beauty? I’ve loved math since I was a kid because it felt like a big game and because it seemed like the laziest thing you could do mentally. After all, how many facts do you need to remember to do math? Later in college, I got excited by physics, which I guess you could say is just a grand exercise in applying math to understand the universe. My roommate, a brainy math major, used to bait me, saying that I never really understood the math I was using. I would counter that he never understood what on Earth the math he studied was good for. We were both right, but he’d be happy to know that I’ve come around to his side: Math is beautiful on a purely abstract level, quite apart from its ability to explain the world. We all know that art, music and nature are beautiful. They command the senses and incite emotion. Their impact is swift and visceral. How can a mathematical idea inspire the same feelings? Well, for one thing, there is something very appealing about the notion of universal truth — especially at a time when people entertain the absurd idea of alternative facts. The Pythagorean theorem still holds, and pi is a transcendental number that will describe all perfect circles for all time. © 2017 The New York Times Company

Keyword: Brain imaging
Link ID: 23498 - Posted: 04.17.2017

By Niall Firth The firing of every neuron in an animal’s body has been recorded, live. The breakthrough in imaging the nervous system of a hydra – a tiny, transparent creature related to jellyfish – as it twitches and moves has provided insights into how such simple animals control their behaviour. Similar techniques might one day help us get a deeper understanding of how our own brains work. “This could be important not just for the human brain but for neuroscience in general,” says Rafael Yuste at Columbia University in New York City. Instead of a brain, hydra have the most basic nervous system in nature, a nerve net in which neurons spread throughout its body. Even so, researchers still know almost nothing about how the hydra’s few thousand neurons interact to create behaviour. To find out, Yuste and colleague Christophe Dupre genetically modified hydra so that their neurons glowed in the presence of calcium. Since calcium ions rise in concentration when neurons are active and fire a signal, Yuste and Dupre were able to relate behaviour to activity in glowing circuits of neurons. For example, a circuit that seems to be involved in digestion in the hydra’s stomach-like cavity became active whenever the animal opened its mouth to feed. This circuit may be an ancestor of our gut nervous system, the pair suggest. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging; Evolution
Link ID: 23483 - Posted: 04.12.2017

By Michael Price Do the anatomical differences between men and women—sex organs, facial hair, and the like—extend to our brains? The question has been as difficult to answer as it has been controversial. Now, the largest brain-imaging study of its kind indeed finds some sex-specific patterns, but overall more similarities than differences. The work raises new questions about how brain differences between the sexes may influence intelligence and behavior. For decades, brain scientists have noticed that on average, male brains tend to have slightly higher total brain volume than female ones, even when corrected for males’ larger average body size. But it has proved notoriously tricky to pin down exactly which substructures within the brain are more or less voluminous. Most studies have looked at relatively small sample sizes—typically fewer than 100 brains—making large-scale conclusions impossible. In the new study, a team of researchers led by psychologist Stuart Ritchie, a postdoctoral fellow at the University of Edinburgh, turned to data from UK Biobank, an ongoing, long-term biomedical study of people living in the United Kingdom with 500,000 enrollees. A subset of those enrolled in the study underwent brain scans using MRI. In 2750 women and 2466 men aged 44–77, Ritchie and his colleagues examined the volumes of 68 regions within the brain, as well as the thickness of the cerebral cortex, the brain’s wrinkly outer layer thought to be important in consciousness, language, memory, perception, and other functions. © 2017 American Association for the Advancement of Science

Keyword: Sexual Behavior; Brain imaging
Link ID: 23478 - Posted: 04.11.2017