Chapter 3. Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
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Silk has walked straight off the runway and into the lab. According to a new study published in the Journal of Clinical Investigation, silk implants placed in the brain of laboratory animals and designed to release a specific chemical, adenosine, may help stop the progression of epilepsy. The research was supported by the National Institute of Neurological Disorders and Stroke (NINDS) and the National Institute of Biomedical Imaging and Bioengineering (NIBIB), which are part of the National Institutes of Health. The epilepsies are a group of neurological disorders associated with recurring seizures that tend to become more frequent and severe over time. Adenosine decreases neuronal excitability and helps stop seizures. Earlier studies have suggested abnormally low levels of adenosine may be linked to epilepsy. Rebecca L. Williams-Karnesky, Ph.D. and her colleagues from Legacy Research Institute, Portland, Ore., Oregon Health and Sciences University (OHSU), Portland, and Tufts University, Boston, looked at long-term effects of an adenosine-releasing silk-implant therapy in rats and examined the role of adenosine in causing epigenetic changes that may be associated with the development of epilepsy. The investigators argue that adenosine’s beneficial effects are due to epigenetic modifications (chemical reactions that change the way genes are turned on or off without altering the DNA code, the letters that make up our genetic background). Specifically, these changes happen when a molecule known as a methyl group blocks a portion of DNA, affecting which genes are accessible and can be turned on. If methyl groups have been taken away (demethylated), genes are more likely to turn on.
Link ID: 18409 - Posted: 07.27.2013
by Carl Zimmer Inside each of us is a miniature version of ourselves. The Canadian neurologist Wilder Penfield discovered this little person in the 1930s, when he opened up the skulls of his patients to perform brain surgery. He would sometimes apply a little electric jolt to different spots on the surface of the brain and ask his patients–still conscious–to tell him if they felt anything. Sometimes their tongues tingled. Other times their hand twitched. Penfield drew a map of these responses. He ended up with a surreal portrait of the human body stretched out across the surface of the brain. In a 1950 book, he offered a map of this so-called homunculus. For brain surgeons, Penfield’s map was a practical boon, helping them plan out their surgeries. But for scientists interested in more basic questions about the brain, it was downright fascinating. It revealed that the brain organized the sensory information coming from the skin into a body-like form. There were differences between the homunculus and the human body, of course. It was as if the face had been removed from the head and moved just out of reach. The area that each body part took up in the brain wasn’t proportional to its actual size. The lips and index finger were gigantic, for instance, while the forearm barely took up less space than the tongue. That difference in our brains is reflected in our nerve endings. Our fingertips are far more sensitive than our backs. We simply don’t need to make fine discriminations with our backs. But we use our hands for all sorts of things–like picking up objects or using tools–that demand that sort of sensory power.
Keyword: Pain & Touch
Link ID: 18407 - Posted: 07.25.2013
By SABRINA TAVERNISE WASHINGTON — The Food and Drug Administration announced on Monday that it had approved the first brain wave test to help diagnose attention deficit hyperactivity disorder in children. The test uses an electroencephalogram, or EEG, with sensors attached to a child’s head and hooked by wires to a computer to measure brain waves. It traces different types of electrical impulses given off by nerve cells in the brain and records how many times those impulses are given off each second. The test takes 15 to 20 minutes, and measures two kinds of brain waves — theta and beta. Certain combinations of those waves tend to be more prevalent in children with A.D.H.D., the Food and Drug Administration said in a news release. The disorder is one of the most common behavioral disorders in children. About 9 percent of adolescents have A.D.H.D. and the average age of diagnosis is 7, the drug agency said, citing the American Psychiatric Association. Children who have it tend to be hyperactive, impulsive and exhibit behavioral problems. The maker of the testing device, NEBA Health of Augusta, Ga., gave the F.D.A. data from a study of 275 children and adolescents, ages 6 to 17, with attention or hyperactivity problems. Clinicians used the device, called a Neuropsychiatric EEG-Based Assessment Aid, in combination with traditional testing methods, like listing the criteria in the Diagnostic and Statistical Manual of Mental Disorders, behavioral questionnaires and I.Q. testing. An outside group of researchers then reviewed the data and decided whether the child had the disorder. The results showed that the device helped doctors make a more accurate diagnosis than using traditional methods alone, the F.D.A. said. An agency spokeswoman said it did not release the study’s data. © 2013 The New York Times Company
Link ID: 18380 - Posted: 07.16.2013
Gregory Gage is being honored as a Champion of Change for his dedication to increasing public engagement in science and science literacy. Science has a rich history of everyday citizens assisting in great discoveries, and I am honored that our work to encourage amateur neuroscience has been selected by The White House for the Citizen Science Champion of Change award. We know a lot about how our amazing brain works, but there is much, much more that remains to be discovered. In fact, we have no cures and only insufficient treatments for neurological disorder, even though about 1 out of every 5 people will be diagnosed with a brain disease. Change is indeed needed in our nation’s approach to science education to bring more focus on neuroscience. I am a “DIY” neuroscientist. I co-founded a low-fi company called Backyard Brains with my grad-school labmate, Tim Marzullo. While working on our Ph.D., we would often go out to local public schools to talk about the importance of studying neuroscience. We developed our lesson plans using models and analogies about how the brain works, but what we really wanted to teach the students was “electrophysiology”... as this is truly is how the brain works. The brain is an electrical organ, and the cells (neurons) communicate with “spikes”: a brief pulse of electricity. In my research at the university, I would record these spikes to learn what the neurons were telling us about how the brain worked. Traditionally, to do experiments with electrophysiology, one needs to be in a Ph.D. program and use expensive equipment (our electrophysiology rig cost $40,000). To make this accessible for our outreach goals, Tim and I set out on a self-imposed engineering challenge: to reduce this equipment down to the basic components, and record a spike for <$100. Less than a year later, we got our first prototype to work and were able to bring spikes into the classrooms! After getting requests from colleagues and teachers, we launched Backyard Brains. We are now a growing education company with neuroscience gear in over 45 countries on all 7 continents!
Link ID: 18349 - Posted: 07.06.2013
by Anil Ananthaswamy Name: Sandra Condition: Ecstatic epilepsy "It's like when you have an orgasm. You don't get to the orgasm in one step. You go progressively. [My seizure] was the same kind of thing." Sandra thinks she had her earliest epileptic seizures when she was just 4 years old. But they were no ordinary seizures. Hers gave her an intense feeling of bliss. Blissful is not how most of us think of epilepsy. Fabienne Picard at the University Hospital Geneva, in Switzerland, says Sandra experienced a form of partial seizure – one localised to a specific region of the brain – known as an ecstatic seizure. These were immortalised in literature by the Russian novelist Fyodor Dostoevsky, who also had them. Dostoevsky described his seizures in a letter to a friend: "I feel entirely in harmony with myself and the whole world, and this feeling is so strong and so delightful that for a few seconds of such bliss one would gladly give up 10 years of one's life, if not one's whole life." To explain how she felt during her seizures, Sandra makes an analogy with a highly pleasurable event. "It's like when you have an orgasm," she says. "You don't get to the orgasm in one step. You go progressively. [The seizure] was the same kind of thing." However, "it was not a sexual feeling", she says. "It was more psychological." © Copyright Reed Business Information Ltd.
Link ID: 18298 - Posted: 06.22.2013
by Alyssa Danigelis Next time you happen across an enormous cockroach, check to see whether it’s got a backpack on. Then look for the person controlling its movements with a phone. The RoboRoach has arrived. The RoboRoach is a system created by University of Michigan grads who have backgrounds in neuroscience, Greg Gage and Tim Marzullo. They came up with the cyborg roach idea as part of an effort to show students what real brain spiking activity looks like using off-the-shelf electronics. Essentially the RoboRoach involves taking a real live cockroach, putting it under anesthesia and placing wires in its antenna. Then the cockroach is outfitted with a special lightweight little backpack Gage and Marzullo developed that sends pulses to the antenna, causing the neurons to fire and the roach to think there’s a wall on one side. So it turns. The backpack connects to a phone via Bluetooth, enabling a human user to steer the cockroach through an app. Why? Why would anyone do this? ”We want to create neural interfaces that the general public can use,” the scientists say in a video. “Typically, to understand how these hardware devices and biological interfaces work, you’d have to go to graduate school in a neuro-engineering lab.” They added that the product is a learning tool, not a toy, and through it they hope to start a neuro-revolution. Currently the duo’s Backyard Brains startup is raising money through a Kickstarter campaign to develop more fine-tuned prototypes, make them more affordable, and extend battery life. The startup says it will make the RoboRoach hardware by hand in an Ann Arbor hacker space. © 2013 Discovery Communications, LLC
Link ID: 18264 - Posted: 06.12.2013
Kerri Smith Researchers have both created and relieved symptoms of obsessive-compulsive disorder (OCD) in genetically modified mice using a technique that turns brain cells on and off with light, known as optogenetics. The work, by two separate teams, confirms the neural circuits that contribute to the condition and points to treatment targets. It also provides insight into how quickly compulsive behaviours can develop — and how quickly they might be soothed. The results of the studies are published in Science1, 2. Brain scanning in humans with OCD has pointed to two areas — the orbitofrontal cortex, just behind the eyes, and the striatum, a hub in the middle of the brain — as being involved in the condition's characteristic repetitive and compulsive behaviours. But “in people we have no way of testing cause and effect”, says Susanne Ahmari, a psychiatrist and neuroscientist at Columbia University in New York who led one of the studies. It is not clear, for example, whether abnormal brain activity causes the compulsions, or whether the behaviour simply results from the brain trying to hold symptoms at bay by compensating. “There’s been a big debate in the field,” says Satinder Kaur Singh of Yale University in New Haven, Connecticut, who studies molecules involved in OCD-like disorders but was not involved in the new studies. “What the Ahmari paper shows is that it is causative.” © 2013 Nature Publishing Group
Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 18248 - Posted: 06.08.2013
By James Gallagher Health and science reporter, BBC News An experimental treatment to stop the body attacking its own nervous system in patients with multiple sclerosis (MS) appears safe in trials. The sheath around nerves cells, made of myelin, is destroyed in MS, leaving the nerves struggling to pass on messages. A study on nine patients, reported in Science Translational Medicine, tried to train the immune system to cease its assault on myelin. The MS Society said the idea had "exciting potential". As nerves lose their ability to talk to each other, the disease results in problems moving and balancing and can affect vision. There are drugs that can reduce number and severity of attacks, but there is no cure. The disease is caused by the body's immune system thinking that myelin is a foreign body like a flu virus. Researchers at the Northwestern University Feinberg School of Medicine developed a technique to retrain the immune system. They took blood samples and coupled white blood cells, a part of the immune system, to fragments of myelin. This was injected back into the patients to make them tolerate myelin. BBC © 2013
By Geoffrey Mohan Hyperactive brain cells firing together could be an early indicator of autism and developmental disabilities, a team of UCLA researchers has found. Networks of neurons were found to be firing in a highly synchronized and seemingly unrelenting fashion, even through sleep, in the brains of juvenile mice that have a genetic abnormality similar to one that causes mental retardation and autism symptoms in humans, according to the research published online Monday in Nature Neuroscience. Without independently firing neurons, the human brain would be about as functionally complicated as a digital switch. With it, we compose poetry and send robotic carts to Mars. "If you want to code information, you can’t just have all the cells fire together or not, because then that’s just binary. It goes up and down," said UCLA neuroscientist Carlos Portera-Cailliau, a lead author of the report. “But if you have billions of neurons, all firing independently or in small clusters, then you can code a lot of information.” That “de-synchronization” was greatly diminished in the neocortex of the juvenile mice that had been altered so that they lack the same protein known to cause mental retardation and autistic behaviors in humans. These so-called Fmr1 Knockout mice, named for the gene that is knocked out, exhibit autism behaviors, among them social deficits – they don’t go over and sniff and examine a new mouse introduced to the cage, like wild mice would. Copyright 2013
Link ID: 18235 - Posted: 06.05.2013
Kerri Smith When Karl Deisseroth moved into his first lab in 2004, he found himself replacing a high-profile tenant: Nobel-prizewinning physicist Steven Chu. “His name was still on the door when I moved in,” says Deisseroth, a neuroscientist, of the basement space at Stanford University in California. The legacy has had its benefits. When chemistry student Feng Zhang dropped by looking for Chu, Deisseroth convinced him to stick around. “I don't think he knew who I was. But he got interested enough.” Deisseroth is now a major name in science himself. He is associated with two blockbuster techniques that allow researchers to show how intricate circuits in the brain create patterns of behaviour. The development of the methods, he says, came from a desire to understand mechanisms that give rise to psychiatric disease — and from the paucity of techniques to do so. “It was extremely clear that for fundamental advances in these domains I would have to spend time developing new tools,” says Deisseroth. His measured tone and laid-back demeanour belie the frenzy that his lab's techniques are generating in neuroscience. First came optogenetics1, which involves inserting light-sensitive proteins from algae into neurons, allowing researchers to switch the cells on and off with light. Deisseroth developed the method shortly after starting his lab, working with Zhang and Edward Boyden, a close collaborator at the time. Optogenetics has since been adopted by scientists around the world to explore everything from the functions of neuron subtypes to the circuits altered in depression or autism. Deisseroth has lost count of how many groups are using it. “We sent clones to thousands of laboratories,” he says. © 2013 Nature Publishing Group
Keyword: Brain imaging
Link ID: 18210 - Posted: 05.30.2013
By Nathan Seppa Multiple sclerosis, long considered a disease of white females, has affected more black women in recent years, a new study finds. Hispanic and Asian women, who have previously seemed to be at less risk of MS, remain so, researchers report May 7 in Neurology. The findings bolster a theory that vitamin D deficiency, which is common in people with dark skin in northern latitudes, contributes to MS. MS is a debilitating condition in which the protective coatings on nerves in the central nervous system get damaged, resulting in a loss of motor control, muscle weakness, vision complications and other problems. The National Multiple Sclerosis Society estimates that 2.1 million people worldwide have the condition. The researchers scanned medical information from 3.5 million people who were members of the health maintenance organization Kaiser Permanente Southern California and found that 496 people received diagnoses of MS from 2008 through 2010. Of these patients, women comprised 70 percent, not an unusual fraction for people with MS. Surprisingly, the patients included 84 black women. That means the annual incidence of MS in black women was 10.2 cases per 100,000 people. That’s not a great risk for an individual, but it was higher than the annual rates for white, Hispanic and Asian women, which were 6.9, 2.9 and 1.4 per 100,000 people, respectively. Among blacks, women had three times the incidence as men; in the other racial and ethnic groups, the MS rate in women was roughly double that of men. © Society for Science & the Public 2000 - 2013
By Ingrid Wickelgren I have seen the invisible arms of multiple sclerosis, a potentially devastating disease of the nervous system, touch friends, relatives and acquaintances. They perturbed the personality of a father of a close friend and left him unable to keep a job and support the family. They forced a young woman I met years ago to walk tentatively, watching her step. They put one beloved member of my extended family with two small children in a wheelchair and took away his voice. Nowadays, many people with MS find that new medications can mitigate the progression of their disease (see “New Treatments Tackle Multiple Sclerosis,” by James D. Bowen, Scientific American Mind, July/August 2013). But many mysteries remain about the cause of the disorder and no one knows how to prevent or cure it. About a decade ago, a technology entrepreneur named Art Mellor, who was diagnosed with MS in 2000, founded an organization called Accelerated Cure Project based in Waltham, Massachusetts to help speed progress on solving these mysteries, in part through greater collaboration among scientists. In one of its efforts, it maintains a repository of thousands of blood samples from patients who visited any of 10 U.S. clinics. The samples are made available to anyone willing to share their data with the Project. Scientists have used these samples in more than 70 different studies into the causes of MS and how to diagnose and treat it. A number of these experiments involve trying to identify molecular signs of the disease in the blood, in hopes of developing a simple blood test for the disorder. Such a test might reduce the time and cost of an MS diagnosis. The primary tool for spotting MS today is magnetic resonance imaging (MRI), which can reveal inflammation in the brain characteristic of the disorder. © 2013 Scientific American
Keyword: Multiple Sclerosis
Link ID: 18132 - Posted: 05.08.2013
National Institutes of Health researchers used the popular anti-wrinkle agent Botox to discover a new and important role for a group of molecules that nerve cells use to quickly send messages. This novel role for the molecules, called SNARES, may be a missing piece that scientists have been searching for to fully understand how brain cells communicate under normal and disease conditions. "The results were very surprising,” said Ling-Gang Wu, Ph.D., a scientist at NIH’s National Institute of Neurological Disorders and Stroke. “Like many scientists we thought SNAREs were only involved in fusion." Every day almost 100 billion nerve cells throughout the body send thousands of messages through nearly 100 trillion communication points called synapses. Cell-to-cell communication at synapses controls thoughts, movements, and senses and could provide therapeutic targets for a number of neurological disorders, including epilepsy. Nerve cells use chemicals, called neurotransmitters, to rapidly send messages at synapses. Like pellets inside shotgun shells, neurotransmitters are stored inside spherical membranes, called synaptic vesicles. Messages are sent when a carrier shell fuses with the nerve cell’s own shell, called the plasma membrane, and releases the neurotransmitter “pellets” into the synapse. SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) are three proteins known to be critical for fusion between carrier shells and nerve cell membranes during neurotransmitter release.
by Sara Reardon People with epilepsy have to learn to cope with the unpredictable nature of seizures – but that could soon be a thing of the past. A new brain implant can warn of seizures minutes before they strike, enabling them to get out of situations that could present a safety risk. Epileptic seizures are triggered by erratic brain activity. The seizures last for seconds or minutes, and their unpredictability makes them hazardous and disruptive for people with epilepsy, says Mark Cook of the University of Melbourne in Australia. Like earthquakes, "you can't stop them, but if you knew when one was going to happen, you could prepare", he says. With funding from NeuroVista, a medical device company in Seattle, Cook and his colleagues have developed a brain implant to do just that. The device consists of a small patch of electrodes that measure brain wave activity. Warning light Over time, the device's software learns which patterns of brainwave activity indicate that a seizure is about to happen. When it detects such a pattern, the implant then transmits a signal through a wire to a receiver implanted under the wearer's collarbone. This unit alerts the wearer by wirelessly activating a handheld gadget with coloured lights – a red warning light, for example, signals that a seizure is imminent. © Copyright Reed Business Information Ltd.
by Sara Reardon An electronic patch can analyse complex brainwaves and listen in on a fetus’s heart MIND reading can be as simple as slapping a sticker on your forehead. An "electronic tattoo" containing flexible electronic circuits can now record some complex brain activity as accurately as an EEG. The tattoo could also provide a cheap way to monitor a developing fetus. The first electronic tattoo appeared in 2011, when Todd Coleman at the University of California, San Diego, and colleagues designed a transparent patch containing electronic circuits as thin as a human hairMovie Camera. Applied to skin like a temporary tattoo, these could be used to monitor electrophysiological signals associated with the heart and muscles, as well as rudimentary brain activity. To improve its usefulness, Coleman's group has now optimised the placement of the electrodes to pick up more complex brainwaves. They have demonstrated this by monitoring so-called P300 signals in the forebrain. These appear when you pay attention to a stimulus. The team showed volunteers a series of images and asked them to keep track of how many times a certain object appeared. Whenever volunteers noticed the object, the tattoo registered a blip in the P300 signal. The tattoo was as good as conventional EEG at telling whether a person was looking at the target image or another stimulus, the team told a recent Cognitive Neuroscience Society meeting in San Francisco. © Copyright Reed Business Information Ltd.
Kristoffer Famm, et al. Imagine a day when electrical impulses are a mainstay of medical treatment. Your clinician will administer 'electroceuticals' that target individual nerve fibres or specific brain circuits to treat an array of conditions. These treatments will modulate the neural impulses controlling the body, repair lost function and restore health. They could, for example, coax insulin from cells to treat diabetes, regulate food intake to treat obesity and correct balances in smooth-muscle tone to treat hypertension and pulmonary diseases. All this is within reach if researchers from disparate disciplines in academia and industry work together. Here, we outline what needs to be done to bring about electroceuticals and unveil a public–private research initiative and an award that we hope will catalyse the field. Electrical impulses — action potentials — are the language of the body's nervous system. Virtually all organs and functions are regulated through circuits of neurons communicating through such impulses1. Two features make these circuits excellent targets for therapeutic intervention. First, they comprise discrete components — interconnected cells, fibre tracts and nerve bundles — allowing for pinpoint intervention. Second, they are controlled by patterns of action potentials, which can be altered for treatment. Already, devices that harness electrical impulses are used to treat disease. Pacemakers and defibrillators save millions of lives each year; deep-brain stimulation dramatically improves the quality of life for people with Parkinson's disease and depression; sacral-nerve stimulation restores some bladder control in people with paraplegia, and vagus-nerve stimulation shows clinical benefits in diseases ranging from epilepsy to rheumatoid arthritis2. But these devices do not target specific cells within circuits. © 2013 Nature Publishing Group
By Scicurious In his State of the Union this year, President Obama referred to increasing support for science and technology, and mentioned the “Brain Activity Map”. Of course neuroscientists were instantly atwitter. It was the first we’d all heard of any Brain Activity Map. What is it? What did it mean? After a lot of speculation and some quickly formed opinions about whether or not it was a good idea…the White House has now unveiled what the project actually is: BRAIN, Brain Research through Advancing Innovative Neurotechnologies. And what is the project exactly? Will the BRAIN project end up as a BAM (Brain Activity Map)? Or a BUST (Badly Underfunded S**T)? I’d like to explore what I know, and I’d like to hear what everyone else knows as well. Am I wrong? Am I too optimistic? Too pessimistic? Have at. What is the BRAIN Project about? What are its goals? Well, nobody knows, actually. I certainly don’t know. But it appears that no one else knows either. “This working group, co-chaired by Dr. Cornelia “Cori” Bargmann (The Rockefeller University) and Dr. William Newsome (Stanford University), is being asked to articulate the scientific goals of the BRAIN initiative and develop a multi-year scientific plan for achieving these goals, including timetables, milestones, and cost estimates.” So basically, BRAIN is a very fancy initiative, with a fancy name…and so far, no goals. And of course, we’re all excited and trying to figure out what it’s going to be and whether or not it will work. Maybe it would have been in the better interest of the White House to wait until there were…you know, goals. But there is one goal that seems established here: new technologies. © 2013 Scientific American
Keyword: Brain imaging
Link ID: 18004 - Posted: 04.09.2013
By Sara Reardon and Bob Holmes, When President Obama called for $100 million in federal funding last week to map the human brain, he said he was hoping to “unlock the mystery of the three pounds of matter that sits between our ears.” Scientists hope that tracking brain activity neuron by neuron — an effort now called the Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative — will revolutionize our understanding of brain function in the same way that the Human Genome Project is transforming our understanding of our genes. But just how do you go about mapping a brain? This is a question that two projects with similar lofty goals are already grappling with. The Human Brain Project aims to do it by creating a computer simulation of the entire brain. The Human Connectome Project is using magnetic resonance imaging to track the fibers that connect different regions of the brain on the millimeter scale, giving a rough-grained road map of the brain. To succeed, researchers will need to find noninvasive ways to record the firing of individual neurons, because all current methods involve opening the skull and, often, sticking electrodes into brain tissue. “Right now, you’re literally driving posts into the brain. It’s not very sophisticated,” says neurobiologist John Ngai of the University of California at Berkeley. A few groups are working on new approaches. The MindScope project at the Allen Institute for Brain Science in Seattle aims to map the visual cortex of mice. The team identifies where neurons are firing by injecting the brain with dyes or using genetically engineered proteins that bind to calcium molecules. When a neuron fires, calcium flows into the cell and activates the dye or protein. © 1996-2013 The Washington Post
Keyword: Brain imaging
Link ID: 18003 - Posted: 04.09.2013
By Meghan Rosen Save the clunky tricorders for Star Trek. One day, tiny biological computers with DNA-based circuitry could diagnose diseases. Using snippets of DNA and DNA-clipping chemicals, researchers have created one key component of a computer’s brain: the transistor, a switch that helps electronics perform logic. The biological switch, dubbed a transcriptor, could be plugged together with other biological devices to boost the power of DNA-based computers, researchers report March 28 in Science. With these switches, researchers might be able to program probiotic bacteria — the kind found in yogurt — to detect signs of colon cancer and then spit out warning signals, says study coauthor Jerome Bonnet of Stanford University. “The bacteria could actually travel through your gut and make a color in your poop,” he says. Inside every smartphone, television and iPod, a computer chip holds circuits loaded with millions of transistors. By flipping on or off, the tiny switches direct electrical current to different parts of the chip. But inside cells, even just a few linked-up switches could be powerful, says synthetic biologist Timothy Lu of MIT. The simple circuits “probably wouldn’t be able to compute square roots,” he says, “but you don’t need to put a MacBook chip inside a cell to get some really interesting functions.” And genetic computers can go places conventional electronics can’t. Instead of controlling the flow of electrons across metal circuit wires, the biological switches control the flow of a protein along a “wire” of DNA in living bacteria. As the protein chugs along the wire, it sends out messages telling the cell to make specific molecules — molecules that color a person’s poop green, for example. © Society for Science & the Public 2000 - 2013
Link ID: 17986 - Posted: 04.03.2013
By DENISE GRADY A treatment that many people with multiple sclerosis had hoped would prove effective has failed its first rigorous test, according to a new study. The treatment uses balloons — the type commonly employed to open blocked arteries in people with heart disease — to widen veins in the head and neck. The technique is based on the unproven theory that narrowed veins cause multiple sclerosis by stopping blood from draining out of the brain properly, which is thought to damage nerves and the fatty sheath, myelin, that insulates them. A vascular surgeon from Italy, Dr. Paolo Zamboni, is the leading proponent of the idea. In recent years, 30,000 people around the world have flocked to clinics offering the balloon treatment, despite the lack of solid evidence for it. Many patients want it because the standard drug treatments have not helped. Multiple sclerosis is incurable and causes progressive disability that eventually forces many patients to use wheelchairs. Some people think the balloon treatment has helped them, and testimonials on the Internet have helped create a powerful demand for the procedure. Researchers at the University at Buffalo recruited 20 patients with the disease to test the theory. Half were picked at random to receive the treatment, and the other half underwent a “sham” procedure in which doctors did not actually use balloons. The patients did not know whether their veins had been expanded, and neither did the people who assessed them later. The patients were monitored for six months. There were no significant differences between the two groups in symptoms or tests used to measure the quality of life, the researchers reported last month at a meeting of the American Academy of Neurology in San Diego. In a few cases, brain lesions associated with the disease actually seemed to worsen after the treatment. © 2013 The New York Times Company
Keyword: Multiple Sclerosis
Link ID: 17977 - Posted: 04.02.2013