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By Dwayne Godwin and Jorge Cham Dwayne Godwin is a neuroscientist at the Wake Forest University School of Medicine. Jorge Cham draws the comic strip Piled Higher and Deeper at www.phdcomics.com. © 2012 Scientific American

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 17504 - Posted: 11.19.2012

By DENISE GRADY Just when they might have thought they were in the clear, people recovering from meningitis in an outbreak caused by a contaminated steroid drug have been struck by a second illness. The new problem, called an epidural abscess, is an infection near the spine at the site where the drug — contaminated by a fungus — was injected to treat back or neck pain. The abscesses are a localized infection, different from meningitis, which affects the membranes covering the brain and spinal cord. But in some cases, an untreated abscess can cause meningitis. The abscesses have formed even while patients were taking powerful antifungal medicines, putting them back in the hospital for more treatment, often with surgery. The problem has just begun to emerge, so far mostly in Michigan, which has had more people sickened by the drug — 112 out of 404 nationwide — than any other state. “We’re hearing about it in Michigan and other locations as well,” said Dr. Tom M. Chiller, the deputy chief of the mycotic diseases branch of the Centers for Disease Control and Prevention. “We don’t have a good handle on how many people are coming back.” He added, “We are just learning about this and trying to assess how best to manage these patients. They’re very complicated.” In the last few days, about a third of the 53 patients treated for meningitis at St. Joseph Mercy Hospital in Ann Arbor, Mich., have returned with abscesses, said Dr. Lakshmi K. Halasyamani, the chief medical officer. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17449 - Posted: 11.03.2012

By Cari Nierenberg The strange folds and furrows covering a Brazilian man's entire scalp was neither a funky new look nor a hipster trend. Rather the 21-year-old's bizarre looking scalp with its deep skin folds in a pattern said to resemble the surface of the brain is a sign of a rare medical condition known as cutis verticis gyrata. In this week's New England Journal of Medicine, two Brazilian doctors describe this young man's case and share a picture of its odd appearance. When he was 19, the skin on his scalp started to change. It grew thicker, forming many soft, spongy ridges and narrow ruts. Even his hair had an unusual configuration. It was normal in the furrows but sparser over the folds as is common for this strange scalp condition. No doubt, visits to the barber shop as well as washing his squishy scalp and combing his hair were peculiar experiences. Despite the extent of his scalp affected, "the patient did not have the habit of covering his head," with a hat, for instance, says Dr. Karen Schons a dermatologist at the Hospital Universitario de Santa Maria, who examined the patient and co-authored the case study. In fact, the case study reports that "the condition did not bother him cosmetically." © 2012 NBCNews.com

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 17386 - Posted: 10.18.2012

The Crack Team That Removes & Preserves People's Brains Just Hours After They Die by Jeff Wheelwright On average, the residents of Sun City, Arizona, occupy their domiciles for a dozen years. When they depart—almost always by dying—they often leave their brains behind. The stages of physical and mental decline take them from their dream house to a hospital off Del Webb Boulevard, then to a nursing home, and finally back to the medical complex, where researchers harvest their most important organ. Hoping to do good for science, they have enrolled in the Brain and Body Donation Program of the Banner Sun Health Research Institute—widely considered the world’s preeminent brain bank. A large base of well-
documented donors in close proximity sets the Sun City program apart from other repositories, which often have scant information about patients who may be scattered and diverse. Here, healthy, active seniors who eventually die of, say, heart disease, can be compared with others who develop neurodegenerative disorders. Because the two sets of subjects have similar backgrounds, lifestyles, and ethnic traits, changes relating to a brain disease should be easier to detect. The institute is also famed for its crack autopsy team, which responds so quickly that no more than three hours elapse from the time a donor expires to the time that the brain is removed and preserved. “We’re not the biggest brain bank in the world, but we have the highest-quality tissue,” says pathologist Thomas Beach, the program director, who notes that donors must live within a 50-mile radius of the morgue. © 2012, Kalmbach Publishing Co.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17376 - Posted: 10.17.2012

by Michael Marshall THE human brain might be the most complex object in the known universe, but a much simpler set of neurons is also proving to be a tough nut to crack. A tiny wasp has brain cells so small, physics predicts they shouldn't work at all. These miniature neurons might harbour subtle modifications, or they might work completely differently from all other known neurons - mechanically. The greenhouse whitefly parasite (Encarsia formosa) is just half a millimetre in length. It parasitises the larvae of whiteflies and so it has long been used as a natural pest-controller. To find out how its neurons have adapted to miniaturisation, Reinhold Hustert of the University of Göttingen in Germany examined the insect's brain with an electron microscope. The axons - fibres that shuttle messages between neurons - were incredibly thin. Of 528 axons measured, a third were less than 0.1 micrometre in diameter, an order of magnitude narrower than human axons. The smallest were just 0.045 μm (Arthropod Structure & Development, doi.org/jfn). That's a surprise, because according to calculations by Simon Laughlin of the University of Cambridge and colleagues, axons thinner than 0.1 μm simply shouldn't work. Axons carry messages in waves of electrical activity called action potentials, which are generated when a chemical signal causes a large number of channels in a cell's outer membrane to open and allow positively charged ions into the axon. At any given moment some of those channels may open spontaneously, but the number involved isn't enough to accidentally trigger an action potential, says Laughlin - unless the axon is very thin. An axon thinner than 0.1 μm will generate an action potential if just one channel opens spontaneously (Current Biology, doi.org/frfwpz). © Copyright Reed Business Information Ltd

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 17335 - Posted: 10.06.2012

Zoë Corbyn Conventional wisdom says that most retractions of papers in scientific journals are triggered by unintentional errors. Not so, according to one of the largest-ever studies of retractions. A survey1 published in Proceedings of the National Academy of Sciences has found that two-thirds of retracted life-sciences papers were stricken from the scientific record because of misconduct such as fraud or suspected fraud — and that journals sometimes soft-pedal the reason. The survey examined all 2,047 articles in the PubMed database that had been marked as retracted by 3 May this year. But rather than taking journals’ retraction notices at face value, as previous analyses have done, the study used secondary sources to pin down the reasons for retraction if the notices were incomplete or vague. These sources included investigations by the US Office of Research Integrity, and evidence reported by the blog Retraction Watch. The analysis revealed that fraud or suspected fraud was responsible for 43% of the retractions. Other types of misconduct — duplicate publication and plagiarism — accounted for 14% and 10% of retractions, respectively. Only 21% of the papers were retracted because of error (see ‘Bad copy’). Earlier studies had found that the percentage of retractions attributable to error was 1.5–3 times higher2–4. “The secondary sources give a very different picture,” says Arturo Casadevall, a microbiologist at Yeshiva University in New York, and a co-author of the latest study. “Retraction notices are often not accurate.” © 2012 Nature Publishing Group

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 17322 - Posted: 10.02.2012

The brain that revolutionized physics now can be downloaded as an app for $9.99. But it won't help you win at Angry Birds. While Albert Einstein's genius isn't included, an exclusive iPad application launched Tuesday promises to make detailed images of his brain more accessible to scientists than ever before. Teachers, students and anyone who's curious also can get a look. A medical museum under development in Chicago obtained funding to scan and digitize nearly 350 fragile and priceless slides made from slices of Einstein's brain after his death in 1955. The application will allow researchers and novices to peer into the eccentric Nobel winner's brain as if they were looking through a microscope. "I can't wait to find out what they'll discover," said Steve Landers, a consultant for the National Museum of Health and Medicine Chicago who designed the app. "I'd like to think Einstein would have been excited." After Einstein died, a pathologist named Thomas Harvey performed an autopsy, removing the great man's brain in hopes that future researchers could discover the secrets behind his genius. Harvey gave samples to researchers and collaborated on a 1999 study published in the Lancet. That study showed a region of Einstein's brain - the parietal lobe - was 15 percent wider than normal. The parietal lobe is important to the understanding of math, language and spatial relationships. © 2012 Hearst Communications Inc

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17302 - Posted: 09.26.2012

by Carrie Arnold More than a kilometer below the ocean's surface, where the sunless water is inky black, scientists have documented one of nature's most spectacular living light shows. An underwater survey has found that roughly 20% of bottom-dwelling organisms in the Bahamas produce light. Moreover, all of the organisms surveyed by the researchers proved to have visual senses tuned to the wavelengths of light generated by this bioluminescence. The work speaks to the important role self-generated light plays in deep-sea communities, marine biologists say. Bioluminescence has evolved many times in marine species and may help organisms find mates and food or avoid predators. In the middle depths of the ocean—the mesopelagic zone that is located 200 to 1000 meters below the surface—the vast majority of organisms can bioluminesce. Much less was known about bioluminescence in organisms living close to the sea floor. Such benthic organisms are harder to visit or sample and therefore study, says Sönke Johnsen, a marine biologist at Duke University in Durham, North Carolina. With Tamara Frank, a marine biologist at Nova Southeastern University in Florida, and colleagues, Johnsen recently explored four sites in the northern Bahamas in a submersible. The researchers collected the benthic organisms by suctioning them gently into a lightproof box with a vacuum hose. Once back in their shipboard labs, they stimulated bioluminescence in the captured organisms by softly prodding the animals. Those that glowed were tested further to determine the exact wavelength of light emitted. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 0:
Link ID: 17239 - Posted: 09.10.2012

by Douglas Heaven Nanoparticles often meet a sticky end in the brain. In theory, the tiny structures could deliver therapeutic drugs to a brain tumour, but navigating the narrow, syrupy spaces between brain cells is difficult. A spot of lubrication could help. Justin Hanes at Johns Hopkins University in Baltimore, Maryland, was surprised to discover just how impermeable brain tissue is to nanoparticles. "It's very sticky stuff," he says, similar in adhesiveness to mucus, which protects parts of the body – such as the respiratory system – by trapping foreign particles. It was thought that the adhesiveness of brain tissue limited the size of particles that can smoothly spread through the brain. Signalling molecules, nutrients and waste products below 64 nanometres in diameter can pass through the tissue with relative ease, but larger nanoparticles – suitable for delivering a payload of drugs to a specific location in the brain – quickly get stuck. Now Hanes and his colleagues have doubled that size limit. They coated their nanoparticles with a densely-packed polymer shield, which lubricates their surface by preventing electrostatic and hydrophobic interactions with the surrounding tissue. "A nice hydrated shell around the particle prevents it from adhering to cells," says Hanes. Using this approach, they were able to observe the diffusion of nanoparticles 114 nanometres in diameter through live mouse brains and dissected human and rat brain tissue. Hanes believes the true upper size limit now lies somewhere between 114 nm and 200 nm. "Things were starting to slow down at 114," he says. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 17219 - Posted: 08.30.2012

A Brazilian construction worker has survived after a 2m (six-foot) steel rod fell from above and pierced his head, doctors who treated him say. Eduardo Leite was taken to a Rio de Janeiro hospital, where the rod was removed after five hours of surgery. The doctors said Mr Leite, who is expected to spend some two weeks under their care, had responded well to surgery. He narrowly escaped partial paralysis and loss of an eye, they added. The rod is said to have fallen from the fifth floor of a building under construction. It pierced Mr Leite's hard hat, then the back of his skull, before exiting between his eyes. Luiz Alexandre Essinger, chief of staff at the Miguel Couto hospital, said Mr Leite was conscious when he arrived there and explained what had happened to him. "He was taken to the operating room, his skull was opened, they examined the brain and the surgeon decided to pull the metal bar out from the front in the same direction it entered the brain," he said. Mr Leite had "few complaints" after the surgery, Mr Essinger added, saying "it really was a miracle" that he survived. BBC © 2012

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 17183 - Posted: 08.20.2012

By Maria Konnikova It’s 1879, and psychology is just about to be born. The place: the University of Leipzig. The birth parent: Wilhelm Wundt. The deed: establishing the first official university laboratory for the study of psychology, an event taken by many as the line that marks unofficial explorations from empirical, accepted science. The laboratory has four rooms and a handful of students. By the early 1880s, it will grow to an astounding six rooms—and a total of 19 students. In 1883, it will award its first doctoral degree, to the first of Wundt’s advisees, Max Friedrich, on the topic of the time-course of individual psychological processes. That same year will see the publication of the first issue of the Journal Philosophische Studien, the first journal of experimental psychology, established—fittingly—by none other than Wundt. From that point on, the future of the discipline will be assured: psychology will survive, and perhaps even flourish, with the dawn of the new century. It will not be just another experiment gone wrong. That, at least, is the most straightforward story. It’s difficult to pinpoint a date for the birth of Psychology as such. That 1879 laboratory is but one contender, and Wundt, but one possible father. But just think of how many paved the way for Wundt’s achievements. Is it fair to call him the start, or is he rather more of a point of coalescence (if that)? And how far back must we go, if we’re to be really fair? © 2012 Scientific American,

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 17114 - Posted: 08.01.2012

By Brian Alexander When news broke that singer Sheryl Crow has a benign brain tumor called a meningioma, her representative swatted away concern by saying that “half of us are walking around with [a meningioma] but you don’t really know unless you happen to have an MRI.” Well, no. Despite that unnamed representative’s effort to make a brain tumor sound like a pimple, meningiomas are not anywhere near so universal, and, despite the “benign” designation, can be dangerous, leading to severe disabilities, and, in rare cases, death. “About 2 to 3 percent are malignant,” Dr. Elizabeth Claus, director of medical research at the Yale School of Public Health, a neurosurgeon at Boston’s Brigham and Women’s Hospital, and the principal investigator for the multi-institution Meningioma Consortium, explained in an interview. “Then that is a very serious situation because there’s not much in the way of great treatments. They can metastasize, say to the lungs, and no chemotherapy will work for it.” As the name indicates, a meningioma is a cancer of the meninges, the protective lining that surrounds the brain and spinal cord, often also called the dura. It’s true that meningiomas are one of the most common types of brain tumors, comprising about one-third of all benign brain tumors, but meningiomas are not nearly as common as Crow’s rep would have you believe. As of 2005, approximately 138,000 Americans were known to have been diagnosed of meningioma. © 2012 msnbc.com

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 16882 - Posted: 06.07.2012

By Melissa Dahl If you can't stomach the thought of guzzling down eight glasses of water every single day, here's some good news: You're off the hook, more health experts are saying. A new editorial in an Australian public health journal is the latest to bust the widely-repeated health myth we need to guzzle 64 ounces, or eight 8-ounce glasses, of water each day just to stave off dehydration. Actually, we get enough fluids to keep our bodies adequately hydrated from the foods we eat and the beverages we drink -- even from caffeinated drinks like coffee and tea. Turns out, the whole "eight glasses a day" thing "really is no longer the recommendation; the recommendation is drinking to thirst," explains Madelyn Fernstrom, a registered dietitian and TODAY's diet and nutrition editor. Drink when you're thirsty! What a novel idea. It's not a bad idea to consume 64 ounces of fluid a day, but it's not a scientifically proven idea, either. It likely comes from a 1940s recommendation from the Food and Nutrition Board of the National Research Council, which said that adults should ingest about 2.5 liters of water a day. "But the often ignored second half of that statement pointed out that most of the water you need is in the foods you eat," explains Dr. Aaron Carroll, associate professor of Pediatrics and the associate director of Children's Health Services Research at Indiana University School. © 2012 msnbc.com

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 16879 - Posted: 06.06.2012

Why do those first hot days of the year feel so bad? Because our bodies' best methods of coping with heat haven’t been tested in three seasons. But if you’re slogging though your work or workout now, you are already starting the process of acclimatization, which will make you better able to withstand heat all summer. These changes can happen in as little as two weeks, according to Lawrence Armstrong, a bioenergetics expert who has studied heat’s effect on the body since 1982. © 1996-2012 The Washington Post

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 16841 - Posted: 05.26.2012

By Ferris Jabr Over the years, I have taught my copy of Microsoft Word a lot of neuroscience terminology: amygdala, corpus callosum, dendritic spines, voxel. But it always knew what neuron meant. I thought I did too. Neurons—the electrically excitable cells that make up the brain and nervous system—first fascinated me in high school. In college, like so many other students studying the brain, I dutifully memorized the structure of the archetypal neuron. I also remember learning about a few different types of neurons with different shapes and functions: motor neurons that make muscles twitch, for example, and unique sensory neurons in the eyes and nose. Only recently, however, have I begun to recognize and appreciate the extraordinary diversity of cells in the nervous system—cells that differ from one another more than the cells of any other organ. Some neurons send electrical signals along fibers that stretch several feet; other neurons’ branches extend only a few millimeters away from the cell body. Some neurons possess a fractal beauty similar to that of ferns and corals: Purkinje cells, for example, often sport finely branched nets, like a sea fan. But some of their neighbors look more like tangled tumbleweeds. One neuron might appear more or less round under the microscope—like a firework frozen in climax—whereas another might spider through the brain like a daddy longlegs. Neurons not only differ in shape—different types of neurons turn on different sets of genes and not all neurons use the same chemicals to communicate. Excitatory neurons mostly stimulate other cells; inhibitory neurons prefer to stifle. Most neurons fire in patterns, but their tempos vary: some keep a steady beat, others remain largely silent except for the occasional burst of activity and still other cells continually fire like a trigger-happy toddler playing laser tag. To summarize: not all neurons are exactly alike. The brain contains multitudes. mouse-neurons © 2012 Scientific American,

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 15: Language and Our Divided Brain
Link ID: 16794 - Posted: 05.15.2012

By Gary Stix “Superwoman has been rumbled,” declared a Daily Telegraph article in 2001 that chronicled how the human brain’s inability to “multitask” undercuts the prospects for a woman to juggle career and family with any measure of success. The brain as media icon has emerged repeatedly in recent years as new imaging techniques have proliferated—and, as a symbol, it seems to confuse as much as enlighten. The steady flow of new studies that purport to reduce human nature to a series of illuminated blobs on scanner images have fostered the illusion that a nouveau biological determinism has arrived. More often than not, a “neurobiological correlate”— tying together brain activity with a behavioral attribute (love, pain, aggression)—supplies the basis for a journal publication that translates instantly into a newspaper headline. The link between blob and behavior conveys an aura of versimilitude that often proves overly seductive to the reporter hard up to fill a health or science quota. A community of neuroscience bloggers, meanwhile, has taken on the responsibility of rectifying some of these misinterpretations. A study published last week by University College of London researchers—“Neuroscience in the Public Sphere”—tried to imbue this trend with more substance by quantifying and formally characterizing it. “Brain-based information possesses rhetorical power,” the investigators note. “Logically irrelevant neuroscience information [the result of the multitude of correlations that turn up] imbues an argument with authoritative, scientific credibility.” © 2012 Scientific American,

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 16754 - Posted: 05.05.2012

In his second year of neuroscience grad school, Greg Dunn was moonlighting with a different kind of experiment: blowing ink across pieces of paper. The neuron-like pattern it formed was instantly recognizable to him as a neuroscientist. "Ink spreads because it wants to go in the direction of less resistance, and that's probably also the case of when branches grow or neurons grow," he says. "The reason the technique works really well is because it's directly related to how neurons are actually behaving." Dunn calls this the "fractal solution to the universe," which he sees as the "fundamental beauty of nature." He's fascinated that this branching pattern holds true across orders of magnitude, whether that's nanometers for neurons, centimeters for ink, or meters for a tree branch. Since graduating with his PhD last fall, Dunn has continued to spend his days with neurons--big, golden ones ten thousand times the size of neurons in your brain. The former University of Pennsylvania grad student now creates paintings of neurons for a living. © 2012, Kalmbach Publishing Co.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 16730 - Posted: 05.01.2012

By Scicurious I’m sitting here, preparing to write a blog post on thermoregulation. I finished a good run a while ago. The temperatures outside weren’t too extreme (50ish degrees F, so comfortable for a good run), and I was sweating freely when I finished. About an hour later, here I am, in fleecey pants, shirt, socks, hoodie…and sleeping bag. And afghan. And cat. I’m freezing. Really, seriously cold. My nailbeds are almost purple, my hands are like ice, and I’ve got goosebumps all over. I’m almost too cold to shiver. This happens every time I run more than about 5 miles. It happens winter or summer (I think winter is worse, usually in summer it’s a relief!). I’ll go out, run 5 or more miles, come home sweaty and glowing with my happy runner’s high, and about 30 minutes later, once all the sweat is dried, I’ll descend into what I call the “post-run shivers”. They last up to two hours after the run, and are the reason I keep my sleeping bag close to hand. When I’ve asked other runners about it, many of them are mystified. Some of them have only experienced the hot feeling post-run, and tell me they can’t shower immediately, or they’ll come out still sweating! But a few others know what I mean. And I’ve always wondered, what is happening to me? Is it normal? Is it ok? When I learned about how humans regulate their body temperature, I learned that we have a natural temperature “set point” of around 37 degrees Celsius (98.6 degrees Fahrenheit), based in the hypothalamus of our brains, and your body regulates its temperature around that set point. © 2012 Scientific American,

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 16586 - Posted: 03.29.2012

By Stephen Dougherty In the film Amèlie, the main character is a young eccentric woman who attempts to change the lives of those around her for the better. One day Amèlie finds an old rusty tin box of childhood mementos in her apartment, hidden by a boy decades earlier. After tracking down Bretodeau, the owner, she lures him to a phone booth where he discovers the box. Upon opening the box and seeing a few marbles, a sudden flash of vivid images come flooding into his mind. Next thing you know, Bretodeau is transported to a time when he was in the schoolyard scrambling to stuff his pockets with hundreds of marbles while a teacher is yelling at him to hurry up. We have all experienced this: a seemingly insignificant trigger, a scent, a song, or an old photograph transports us to another time and place. Now a group of neuroscientists have investigated the fascinating question: Can a few neurons trigger a full memory? In a new study, published in Nature, a group of researchers from MIT showed for the first time that it is possible to activate a memory on demand, by stimulating only a few neurons with light, using a technique known as optogenetics. Optogenetics is a powerful technology that enables researchers to control genetically modified neurons with a brief pulse of light. To artificially turn on a memory, researchers first set out to identify the neurons that are activated when a mouse is making a new memory. To accomplish this, they focused on a part of the brain called the hippocampus, known for its role in learning and memory, especially for discriminating places. Then they inserted a gene that codes for a light-sensitive protein into hippocampal neurons, enabling them to use light to control the neurons. © 2012 Scientific American

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 16582 - Posted: 03.29.2012

By ABIGAIL ZUGER, M.D. Like creatures battling undersea, pro-life and right-to-die forces are locked in mortal but only intermittently visible combat. The last prominent battle ended almost seven years ago, after the death of Terri Schiavo, the Florida woman with brain damage whose feeding tube was removed by court order in the spring of 2005. Since then, all has been quiet on the surface, belying the continuing turmoil in hospitals and courtrooms over what, exactly, marks the end of life. Invariably, the louder the background tumult, the more useful is the quiet, dispassionate narrative. And so one turns to Dick Teresi’s new book with considerable hope: Surely Mr. Teresi, a veteran science journalist, past editor in chief of Science Digest and Omni, will be the ideal guide through those dim purgatories where life and death can be difficult to distinguish. All starts out promisingly enough. An indefatigable researcher and fluid writer, Mr. Teresi provides a good long riff on death past and present, from the Egyptian mummies, dehydrated into “the deadest people on the planet,” to the ever-hopeful terminally ill of our own age, still flossing their teeth and eating healthy meals in hospice care. Mr. Teresi points out that conclusive signs of death have always been subject to debate. All the great civilizations argued about them, with various expert commentators proposing various fail-safe criteria and yet (Mr. Teresi notes with some pleasure) specifying that they themselves should be left unburied for a few days just to avoid any unfortunate mistakes. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 16578 - Posted: 03.27.2012