Links for Keyword: Miscellaneous

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Cellphone Radiation May Alter Your Brain. Let’s Talk.

By KATE MURPHY In a culture where people cradle their cellphones next to their heads with the same constancy and affection that toddlers hold their security blankets, it was unsettling last month when a study published in The Journal of the American Medical Association indicated that doing so could alter brain activity. The report said it was unclear whether the changes in the brain — an increase in glucose metabolism after using the phone for less than an hour — had any negative health or behavioral effects. But it has many people wondering what they can do to protect themselves short of (gasp) using a landline. “Cellphones are fantastic and have done much to increase productivity,” said Dr. Nora Volkow, the lead investigator of the study and director of the National Institute of Drug Abuse at the National Institutes of Health. “I’d never tell people to stop using them entirely.” Yet, in light of her findings, she advises users to keep cellphones at a distance by putting them on speaker mode or using a wired headset whenever possible. The next best option is a wireless Bluetooth headset or earpiece, which emit radiation at far lower levels. If a headset isn’t feasible, holding your phone just slightly away from your ear can make a big difference; the intensity of radiation diminishes sharply with distance. “Every millimeter counts,” said Louis Slesin, editor of Microwave News, an online newsletter covering health and safety issues related to exposure to electromagnetic radiation. © 2011 The New York Times Company

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: 15158 - Posted: 03.31.2011

Can't dance? Brain chemical throws off your groove

By Bill Briggs All these years, I thought it was because I was white. And straight. And old. Sure, I’ll get my freak on if I hear “Disco Inferno,” or when Mary J. is in the spot. (Told you I was old. And let me add: Don’t need no hateration.) But my steps aren’t smooth. Those beats and my body never truly connect -- despite what the cocktails tell me. On the dance floor, I'm the male Elaine from "Seinfeld," all kicks, thumbs and no rhythm. Turns out, it’s all in my head, not my hips or feet. A study, released today by researchers at the University of Oxford in England, claims a tiny messenger in the brain is partly to blame for those among us who struggle to grasp the latest dance moves. This is all about GABA (short for gamma-aminobutyric acid). Again: not Gaga, GABA. A naturally occurring chemical, GABA is a bit like the brain’s traffic cop. Nerve cells in the brain are constantly firing and “talking” to each other. GABA helps keep all that chatter from getting out of control. “Our research suggests that an important first step in learning that new skill is a decrease in GABA levels in the motor cortex,” explained Dr. Charlotte Stagg, a junior research fellow at Oxford and at John Radcliffe Hospital. Her study was published online in the journal Current Biology. © 2011 msnbc.com

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 15084 - Posted: 03.08.2011

The brain engineer: Shining a light on consciousness

by Rowan Hooper Neuroengineer Ed Boyden is best known for his pioneering work on optogenetics, which allows brain cells to be controlled using light. A speaker at the TED2011 conference this week, his vision, he tells Rowan Hooper, is nothing less than to understand the brain, treat neural conditions and figure out the basis of human existence. Give us your elevator pitch. I run the synthetic neurobiology group. We develop software, electrical and optical tools to allow people to analyse brain dynamics. Unlike a computer, the brain is made of thousands of different types of cell, and we don't know how they work. We need to be able to turn the cells on and off to see how they cooperate to implement brain computations, and how they go awry in brain disorders. What we're doing is making genetically encoded neurons that we can turn on and off with light. By shining light on these cells we can activate them and see what they do. What brain functions will this allow you to study? Scientists now have unprecedented abilities to perturb and record from the brain, and that's allowing us to go after complex ideas like thought and memory. Our tools will help us parse out emotion, memory, attention and consciousness. Put psychology and neuroscience together with neuroengineering, and some of the biggest questions in neuroscience become tractable. Tell us about your tools. The core idea is to take molecules that sense light and convert it into electrical energy, and put them in neurons. We can take a given class of brain cells and develop a virus to deliver genes to these cells. Then we can shine light on these cells and activate them and see what they do. © Copyright Reed Business Information Ltd.

NIH-funded study shows early brain effects of HIV in mouse model

A new mouse model closely resembles how the human body reacts to early HIV infection and is shedding light on nerve cell damage related to the disease, according to researchers funded by the National Institutes of Health. The study in today’s Journal of Neuroscience demonstrates that HIV infection of the nervous system leads to inflammatory responses, changes in brain cells, and damage to neurons. This is the first study to show such neuronal loss during initial stages of HIV infection in a mouse model. The study was conducted by a team of scientists from the University of Nebraska Medical Center, Omaha, and the University of Rochester Medical Center, N.Y. It was supported by the National Institute on Drug Abuse (NIDA), the National Institute of Neurological Disorders and Stroke, the National Institute of Mental Health, and the National Center for Research Resources. "This research breakthrough should help us move forward in learning more about how HIV affects important brain functioning in its initial stages, which in turn could lead us to better treatments that can be used early in the disease process," said Dr. Nora D. Volkow, director of NIDA. "The work contained within this study is the culmination of a 20-year quest to develop a rodent model of the primary neurological complications of HIV infection in humans," said Dr. Howard Gendelman, one of the primary study authors. "Previously, the rhesus macaque was the only animal model for the study of early stages of HIV infection. However, its use was limited due to expense and issues with generalizing results across species. Relevant rodent models that mimic human disease have been sorely needed."

Cellphone Use Tied to Changes in Brain Activity

By TARA PARKER-POPE Researchers from the National Institutes of Health have found that less than an hour of cellphone use can speed up brain activity in the area closest to the phone antenna, raising new questions about the health effects of low levels of radiation emitted from cellphones. The researchers, led by Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, urged caution in interpreting the findings because it is not known whether the changes, which were seen in brain scans, have any meaningful effect on a person’s overall health. But the study, published Wednesday in The Journal of the American Medical Association, is among the first and largest to document that the weak radio-frequency signals from cellphones have the potential to alter brain activity. “The study is important because it documents that the human brain is sensitive to the electromagnetic radiation that is emitted by cellphones,” Dr. Volkow said. “It also highlights the importance of doing studies to address the question of whether there are — or are not — long-lasting consequences of repeated stimulation, of getting exposed over five, 10 or 15 years.” Although preliminary, the findings are certain to reignite a debate about the safety of cellphones. A few observational studies have suggested a link between heavy cellphone use and rare brain tumors, but the bulk of the available scientific evidence shows no added risk. Major medical groups have said that cellphones are safe, but some top doctors, including the former director of the University of Pittsburgh Cancer Center and prominent neurosurgeons, have urged the use of headsets as a precaution. © 2011 The New York Times Company

Justifying research, basic or otherwise

By Laura Sanders WASHINGTON — A panel of neuroscientists describing their basic research on how the brain work were called out on February 20 at the annual meeting of the American Association for the Advancement of Science. Though the work ranged from preliminary studies on the neural networks of songbirds to how humans recognize their bodies, at some point during each presentation, each scientist made mention of the potential medical benefits of his or her work. At the end of all the presentations, session moderator Story Landis of the National Institutes of Health in Bethesda, Md., pointed this out, calling attention to what may have been an unconscious desire to package their data in disease, and so perhaps funding-friendly, terms. “I was struck that all the speakers justify the science that they were doing in the context of human disease, even David [Clayton], who works on archetypal model systems — songbirds — chose or felt obligated to say something about alpha-synuclein and Parkinson’s disease,” she said. “I would be interested in challenging the speakers: Do we have to justify what neuroscientists do in a context of disease, or can we make a sufficiently compelling argument for its intrinsic interest and excitement of neuroscience without having to do that?” David Clayton, a neuroscientist at the University of Illinois at Urbana-Champaign, treaded carefully between the two answers by pointing out that while basic research is valuable, scientists can’t lose sight of what taxpayers are getting for their money: “Understanding how the brain works — that’s the grand challenge — doesn’t exclusively have human medical context,” he said. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 15: Language and Our Divided Brain
Link ID: 15033 - Posted: 02.22.2011

Scientists find neurons communicate at a distance with electric fields

Researchers believed neurons in the brain communicated through physical connections known as synapses. However, EU-funded neuroscientists have uncovered strong evidence that neurons also communicate with each other through weak electric fields, a finding that could help us understand how biophysics gives rise to cognition. The study, published in the journal Nature Neuroscience, was funded in part by the EUSYNAPSE ('From molecules to networks: understanding synaptic physiology and pathology in the brain through mouse models') project, which received EUR 8 million under the 'Life sciences, genomics and biotechnology for health' Thematic area of the EU's Sixth Framework Programme (FP6). Lead author Dr Costas Anastassiou, a postdoctoral scholar at the Californian Institute of Technology (Caltech) in the US, and his colleagues explain how the brain is an intricate network of individual nerve cells, or neurons, that use electrical and chemical signals to communicate with one another. Every time an electrical impulse races down the branch of a neuron, a tiny electric field surrounds that cell. A few neurons are like individuals talking to each other and having small conversations. But when they all fire together, it's like the roar of a crowd at a sports game. That 'roar' is the summation of all the tiny electric fields created by organised neural activity in the brain. While it has long been recognised that the brain generates weak electrical fields in addition to the electrical activity of firing nerve cells, these fields were considered epiphenomenon - superfluous side effects.

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: 14965 - Posted: 02.08.2011

No flu vaccine link to Guillain-Barré syndrome found

By Nathan Seppa Any speculation drawing an ongoing link between flu vaccination and the risk of a rare, paralyzing neuromuscular disorder has been dashed by a huge study. An analysis of side effects recorded among nearly 90 million people in China who were vaccinated during the 2009–2010 flu season found that only 11 people subsequently were diagnosed with Guillain-Barré syndrome, a rate no greater than what normally appears in the population. The study appears online February 2 in the New England Journal of Medicine. In 1976, a strain of swine flu showed up in the United States, prompting the manufacture and delivery more than 40 million doses of vaccine against it. The epidemic ultimately never materialized, but studies noted that hundreds of cases of Guillain-Barré syndrome were reported after the vaccination campaign. The vaccine was withdrawn. In 2003, an Institute of Medicine review found that the evidence pointed to an association between the 1976 swine flu vaccine and the syndrome. IOM found no clear evidence of such a link with subsequent flu vaccines, but some concerns have lingered vis-à-vis flu vaccination. These fears intensified in 2009 when another swine flu emerged, this time known as the H1N1 flu, and a vaccine was made for it. After mass vaccinations, physician Yu Wang and colleagues at the Chinese Centers for Disease Control and Prevention in Beijing collected data on all adverse effects reported by the 89.6 million people in China who received the flu vaccine in 2009 and 2010. The researchers found an exceptionally low rate of Guillain-Barré syndrome among those who had been vaccinated — less than the background rate in the population. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 14949 - Posted: 02.03.2011

Making a worm do more than squirm

By Laura Sanders Satirist Stephen Colbert envisions his “Colbert Nation” mentally marching in lockstep with his special brand of patriotism. But scientists have done him one better, by creating tiny worm-bots completely under their control. Rather than comedic persuasion, these scientists are using a dot of laser light. With it they can make a worm turn left, freeze or lay an egg. The researchers report their work online January 16 in Nature Methods. The new system, named CoLBeRT for “Controlling Locomotion and Behavior in Real Time,” doesn’t just create a mindless zombie-worm, though. It gives scientists the ability to pick apart complicated behaviors on a cell-by-cell basis. “This system is really remarkable,” says biological physicist William Ryu of the University of Toronto, who was not involved in the research. “It’s a very important advance in pursuit of the goal of understanding behavior.” Transparent and small, the nematode C. elegans is particularly amenable to light-based mind control. Another benefit of the worm is that researchers know the precise location of all 302 of its nerve cells. But until now, there wasn’t a good way to study each cell by itself, especially in a wriggling animal. “This tool allows us to go in and poke and prod at those neurons in an animal as it’s moving, and see exactly what each neuron does,” says study coauthor Andrew Leifer of Harvard University. © Society for Science & the Public 2000 - 2011

Lifting a Veil of Fear to See a Few Benefits of Fever

By PERRI KLASS, M.D. Fever is common, but fever is complicated. It brings up science and emotion, comfort and calculation. As a pediatrician, I know fever is a signal that the immune system is working well. And as a parent, I know there is something primal and frightening about a feverish child in the night. So those middle-of-the-night calls from worried parents, so frequent in every pediatric practice, can be less than straightforward. A recent paper in The Journal of the American Medical Association pointed out one reason, and a longstanding discussion about parental perceptions reminds us of the emotional context. The JAMA study looked at over-the-counter medications for children, including those marketed for treating pain and fever: how they are labeled, and whether the droppers and cups and marked spoons in the packages properly reflect the doses recommended on the labels. The article concluded that many medications are not labeled clearly, that some provide no dosing instrument, and that the instruments, if included, are not marked consistently. (A dosing chart might recommend 1.5 milliliters, but the dropper has no “1.5 ml” mark.) “Basically, the main message of the paper is that the instructions on the boxes and bottles of over-the-counter medications are really confusing,” said the lead author, Dr. H. Shonna Yin of New York University Medical Center, who is a colleague of mine and an assistant professor of pediatrics. © 2011 The New York Times Company

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: 14856 - Posted: 01.11.2011

Images of Cell Type: Multipolar neuron

This project is supported by Award Number RC2GM092708 from the National Institute of General Medical Sciences (NIGMS).

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: 14782 - Posted: 12.14.2010

The wonders of the cell go online

John Roach For many of us, the wonders of cell biology came alive when we peered through a microscope at an amoeba in science class. Today, a new online image library of cells brings that same sense of wonder and magic to anyone with an Internet connection. The library contains more than 1,000 images, videos, and animations of cells from a variety of organisms — from the Chinese hamster (Cricetulus griseus) to humans (Homo sapiens). The database aims to advance research on cellular activity with the ultimate goal of improving human health, according to the American Society for Cell Biology, which has created the database in partnership with Glencoe Software and the Open Microscopy Environment. "In our research of disease, one of the key features is to understand the mechanism of disease — and that is going to happen, in many cases, at the cellular level," David Orloff, manager of The Cell image library, told me. For example, the library will make it possible for scientists to compare different cell types online and understand the nature of specific cells and cellular processes, both normal and abnormal. This may lead to new discoveries about diseases, as well as new targets for drug development. © 2010 msnbc.com

Birds Do It ... We Do It ... and No One Knows Why

By NICHOLAS BAKALAR Everyone yawns, but no one knows why. We start when we are in the womb, and we do it through old age. Most vertebrate species, even birds and fishes, yawn too, or at least do something that looks very much like it. But its physiological mechanisms, its purpose and what survival value it might have remain a mystery. There is no shortage of theories — a recent article in the journal Neuroscience & Biobehavioral Reviews outlines many — but a dearth of experimental proof that any of them is correct. “The lack of experimental evidence is sometimes accompanied by passionate discussion,” said Dr. Adrian G. Guggisberg, the lead author. Hippocrates proposed in the fourth century B.C. that yawning got rid of “bad air,” and increased “good air” in the brain. The widely held modern view of this theory is that yawning helps increase blood oxygen levels and decrease carbon dioxide. If this were true, Dr. Guggisberg writes, then people would yawn more when they exercise. And people with lung or heart disease, who often suffer from a lack of oxygen, yawn no more than anyone else. Researchers have exposed healthy subjects to gas mixtures with high levels of carbon dioxide and found that it does not lead to increased yawning. In fact, there is no study that shows that oxygen levels in the brain are changed one way or the other by yawning. Copyright 2010 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 14776 - Posted: 12.14.2010

An Odyssey Through the Brain

By ABIGAIL ZUGER, M.D. Who has seen the mind? Neither you nor I — nor any of the legions of neuroscientists bent on opening the secrets of that invisible force, as powerful and erratic as the wind. The experts are definitely getting closer: the last few decades have produced an explosion of new techniques for probing the blobby, unprepossessing brain in search of the thinking, feeling, suffering, scheming mind. But the field remains technologically complicated, out of reach for the average nonscientist, and still defined by research so basic that the human connection, the usual “hook” by which abstruse science captures general interest, is often missing. Carl Schoonover took this all as a challenge. Mr. Schoonover, 27, is midway through a Ph.D. program in neuroscience at Columbia, and thought he would try to find a different hook. He decided to draw the general reader into his subject with the sheer beauty of its images. So he has compiled them into a glossy new art book. “Portraits of the Mind: Visualizing the Brain From Antiquity to the 21st Century,” newly published by Abrams, includes short essays by prominent neuroscientists and long captions by Mr. Schoonover — but its words take second place to the gorgeous imagery, from the first delicate depictions of neurons sketched in prim Victorian black and white to the giant Technicolor splashes the same structures make across 21st-century LED screens. Copyright 2010 The New York Times Company

Thrown off balance: Inner ear disorders are complex to diagnose and correct.

By Courtney Humphries Two years ago, George Winslow’s world was literally thrown off balance. He was working on cars at the auto repair shop he owns in Foxborough when he began to sweat, and every step felt like a struggle. The world began to spin violently. Unable to get his balance, Winslow slammed to the floor. He lost hearing in one ear. He left the shop in an ambulance, and the world didn’t stop moving for more than four grueling hours. Winslow was diagnosed with Meniere’s disease, a progressive disorder of the inner ear that brings severe, unexpected attacks of vertigo, often accompanied by hearing loss, ringing in the ears, and nausea. From then on, Winslow suffered from frequent attacks of intense dizziness, sometimes three or four a week. An active person who had always preferred to work under the hood rather than behind a desk, he was often exhausted and relying more on the help of his staff. “This is the toughest thing I’ve ever gone through,’’ says Winslow, 54. Because a balance disorder is a complex problem to diagnose, people who suffer them often go from doctor to doctor until, like Winslow, they find specialists who can properly treat the problem. After his local doctor offered little help, Winslow eventually found his way to Dr. Steven Rauch, an otologist at the Massachusetts Eye and Ear Infirmary who specializes in treating balance disorders like Meniere’s. Winslow has undergone a series of treatments that have lessened the frequency and duration of the attacks, and he had minor surgery last week that he hopes will further improve the situation. But although his condition has improved, he’s had to adjust to a life out of balance. © 2010 NY Times Co

Related chapters from BP7e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 14695 - Posted: 11.22.2010

A Direct Hit of Drugs to Treat Brain Cancer

By DENISE GRADY It was a desperate measure, for a desperate disease. Fourteen months ago, Dennis Sugrue let doctors thread a fine tube through his blood vessels and up into his head, so they could spray the drug Avastin directly into the part of his brain where a tumor had been cut out. It was an experiment, devised mainly to find out whether the procedure was safe, and to gauge how much Avastin the brain could tolerate. But Mr. Sugrue, then 50, was hoping the experiment would also free him of cancer. He had glioblastoma, a brain tumor that fights off every known therapy. The same disease killed Senator Edward M. Kennedy last year. Mr. Sugrue’s cancer was diagnosed in April 2009 and bombarded with the usual weapons: surgery, radiation and chemotherapy. Within months, the tumor was growing back. That was when he signed up for the Avastin study. About 10,000 Americans a year develop glioblastoma. Nearly all find that the standard treatments seem to work — for a while. And then the clock starts to run down. With treatment, the median survival is about 15 months. Only 25 percent of patients make it to two years. The disease is the focus of much research, and will almost certainly be for years to come. Hundreds of studies are being conducted in glioblastoma and other brain cancers. Among other things, they involve vaccines, drug combinations and special drug-delivery techniques. Progress is measured in small steps — a few more months of survival, more patients managing to survive two years. On paper the gains may seem minute, but for patients the added time may translate into a graduation or wedding that might otherwise have been missed. Copyright 2010 The New York Times Company

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: 14646 - Posted: 11.09.2010

Hacker’s challenge

by James Garvey So long as people read Wittgenstein, people will read Peter Hacker. It’s hard to imagine how his work on the monumental Analytical Commentary on Wittgenstein’s Philosophical Investigations could possibly be superseded. He spent nearly twenty years on that project (ten of them in cooperation with his friend and colleague Gordon Baker), following in Wittgenstein’s footsteps, and producing a large number of important articles and books on topics in the philosophy of mind and language along the way. Nearer the end than the beginning of a distinguished career as an Oxford don, at a time of life when most academics would be happy to leave the lectern behind and collapse somewhere with a nice glass of wine, Hacker is in the middle of another huge project, this time on human nature. He also seems keen to pick a fight with almost anyone doing the philosophy of mind. This has a much to do with his view of philosophy as a contribution to human understanding, not knowledge. One might think that philosophy has the same general aim as science – securing knowledge of ourselves and the world we live in – even if its subject matter is more abstract and its methods more armchair. What is philosophy if not an attempt to secure new knowledge about the mind or events or beauty or right conduct or what have you? According to Hacker, philosophy is not a cognitive discipline. It’s something else entirely. “Philosophy does not contribute to our knowledge of the world we live in after the manner of any of the natural sciences. You can ask any scientist to show you the achievements of science over the past millennium, and they have much to show: libraries full of well-established facts and well-confirmed theories. If you ask a philosopher to produce a handbook of well-established and unchallengeable philosophical truths, there’s nothing to show.” © 2010 TPM: The Philosophers’ Magazine.

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 14: Attention and Consciousness
Link ID: 14638 - Posted: 11.08.2010

Optogenetics: Controlling the Brain with Light [Extended Version]

By Karl Deisseroth Despite the enormous efforts of clinicians and researchers, our limited insight into psychiatric disease (the worldwide-leading cause of years of life lost to death or disability) hinders the search for cures and contributes to stigmatization. Clearly, we need new answers in psychiatry. But as philosopher of science Karl Popper might have said, before we can find the answers, we need the power to ask new questions. In other words, we need new technology. Developing appropriate techniques is difficult, however, because the mammalian brain is beyond compare in its complexity. It is an intricate system in which tens of billions of intertwined neurons—with multitudinous distinct characteristics and wiring patterns—compute with precisely timed, millisecond-scale electrical signals, as well as with a rich diversity of biochemical messengers. Because of that complexity, neuroscientists lack a deep grasp of what the brain is really doing—of how specific activity patterns within specific brain cells ultimately give rise to thoughts, feelings and memories. By extension, we also do not know how the brain's physical failures produce distinct psychiatric disorders such as depression or schizophrenia. The ruling paradigm of psychiatric disorders—casting them in terms of chemical imbalances and altered levels of neurotransmitters—does not do justice to the brain's high-speed electrical neural circuitry. And psychiatric treatments have historically been largely serendipitous: helpful for many but rarely illuminating, and suffering from the same challenges as basic neuroscience. In a 1979 Scientific American article Nobel laureate Francis Crick suggested that the major challenge facing neuroscience was the need to control one type of cell in the brain while leaving others unaltered. Electrical stimuli cannot meet this challenge because electrodes are too crude a tool: they stimulate all the circuitry at their insertion site without distinguishing between different cell types, and their signals cannot turn off neurons with precision. © 2010 Scientific American,

50 ideas to change science: Neuroscience

Thanks to better brain imaging and biological insights, we're closing in on the neurons of consciousness and the subtleties of our mental machinery Cognitive control Towards the seat of consciousness The question "what is consciousness?" represents one of the great frontiers of contemporary science. Thanks to studies of humans and animals, we now know that it is a subtly nuanced state whose nature and intensity varies according to the brain's intrinsic level of activity, its chemical microclimate and the information it receives from outside. By exploiting the normal vicissitudes of waking, sleeping and dreaming states, we are now beginning to explore how consciousness is expressed and controlled. For example, I have been involved in studies comparing brain activation in REM sleep with that in lucid-dreaming states, in which we retain much executive brain function. They seem to confirm the central importance of one specific area of the frontal brain - the dorsolateral prefrontal cortex - in regulating many key aspects of consciousness, including attention, decision-making and voluntary action. A combination of imaging techniques, judicious measures of subjective experience and detailed cellular and molecular-level studies will continue to deepen our understanding of our cognitive command centres in the coming years. With them we hope to crack the puzzle of consciousness, and perhaps correct the dysfunctional states of the brain we now call mental illness. Allan Hobson © Copyright Reed Business Information Ltd.

Guards of the blood-brain barrier identified

By Rachel Ehrenberg Of all the body’s organs, the brain is the most like Area 51: Entry to the region is severely restricted, thanks to a barricade of cells and molecules known collectively as the blood-brain barrier. Increased surveillance by scientists has now pinpointed the barrier’s senior operatives, cells that are tasked with monitoring the razor wire–like barricade that keeps all but a select few from entering the brain. In two papers published online October 13 in Nature, scientists report that specialized cells called perictyes are crucial in the blood-brain barrier’s development and its maintenance in adulthood. A better understanding of how these pericytes function could help elucidate why some people fare especially poorly after traumatic brain injury or get particular neurological diseases such as cerebral palsy, scientists say. And new research could also lead to tricks for selectively opening or closing the blood-brain barrier, letting in medications that might combat diseases such as Alzheimer’s. One of the new studies demonstrates that pericytes are necessary for cementing the barrier’s cells into a nearly impenetrable wall surrounding blood vessels in the central nervous system. The work also establishes a timeline: In mice, the blood-brain barrier develops well before birth, researchers from Stanford and the University of California, San Francisco report. Pericytes also appear to keep the barrier’s cells on lockdown, dialing down the activity of genes that, if left to their own devices, would spur the transport of molecules across the barrier and into the brain. © Society for Science & the Public 2000 - 2010

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