Chapter 3. Neurophysiology: The Generation, Transmission, and Integration of Neural Signals

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.


Links 81 - 100 of 641

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

Keyword: Robotics
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

by Anil Ananthaswamy, A YOUNG man lies unconscious on the table, his head clamped firmly in place. His eyes are closed. The hair over his left temple has been shaved. I'm in the operating room at University Hospital Zurich in Switzerland with neurologist Thomas Grunwald, who has diagnosed 22-year-old Jeremy Künzler with drug-resistant temporal lobe epilepsy. His symptoms during fits suggest that the seizures begin in the left temporal lobe. Often, this condition can only be treated by surgically removing the errant brain tissue. Unfortunately, brain scans have revealed nothing that would point to the source of Künzler's seizures – no obvious tumour, scar or lesion. In ordinary circumstances, Künzler would have to undergo exploratory brain surgery. But instead of this drastic operation, Grunwald is pioneering a technique to pinpoint the problem area. He has asked neurosurgeon Niklaus Krayenbühl to implant electrodes inside Künzler's skull: a grid electrode over his left temporal lobe, and two strip electrodes beneath the left and right lobes, used to monitor activity bilaterally in the hippocampi and amygdalae. Once they are in place, Grunwald will record brain signals in real time during seizures and use the information to try to identify the epileptogenic tissue. It's my first time inside an operating room. I'm anxious, as I have been told not to touch a thing for fear of contamination, especially the giant surgical microscope covered in clear, sterile plastic. "The nurses are very strict," says Grunwald. "If you touch this, even with your head, they get really angry." © Copyright Reed Business Information Ltd.

Keyword: Epilepsy
Link ID: 17953 - Posted: 03.27.2013

Two years after New Brunswick decided to help multiple sclerosis patients pay for an unproven treatment that's only offered outside the country, the number of patients who have sought the so-called liberation treatment has fallen short of expectations. A leading authority on MS says he's not surprised the numbers are falling off. The Finance Department says since April 1, 2011, 82 people who wanted the treatment that widens constricted veins in the neck have been approved for payments of $2,500 each. Applicants get the government funding if a community group raises matching funds. The provincial government budgeted $400,000 for the program in its first two years of operation — or enough to help 160 people seek the treatment. The government approved 25 applications in the first four months the money was available, but interest has tapered off and there have been no applications in the last two months. “It's getting fewer and fewer because every month a negative study is coming out," said Dr. Jock Murray, a neurologist at Dalhousie University in Halifax. Italian vascular specialist Paolo Zamboni reported dramatic improvements in his patients after he pioneered the procedure, but Murray said none of the subsequent studies done around the world have had the same results. “Every study has tended to be negative," he said. © CBC 2013

Keyword: Multiple Sclerosis
Link ID: 17944 - Posted: 03.25.2013

Monya Baker At first glance, it looks like an oddly shaped campfire: smoky grey shapes light up with red sparks and flashes. But the video actually represents a different sort of crackle — the activity of individual neurons across a larval fish brain. It is the first time that researchers have been able to image an entire vertebrate brain at the level of single cells. “We see the big picture without losing resolution,” says Phillipp Keller, a microscopist at the Howard Hughes Medical Institute's Janelia Farm Research Campus in Ashburn, Virginia, who developed the system with Janelia neurobiologist Misha Ahrens. The researchers are able to record activity across the whole fish brain almost every second, detecting 80% of its 100,000 neurons. (The rest lie in hard-to-access areas, such as between the eyes; their activity is visible but cannot be pinned down to single cells.) The work is published today in Nature Methods1. “It’s phenomenal,” says Rafael Yuste, a neuroscientist at Columbia University in New York. “It is a bright star now in the literature, suggesting that it is not crazy to map every neuron in the brain of an animal.” Yuste has been leading the call for a big biology project2 that would do just that in the human brain, which contains about 85,000 times more neurons than the zebrafish brain. The resolution offered by the zebrafish study will enable researchers to understand how different regions of the brain work together, says Ahrens. With conventional techniques, imaging even 2,000 neurons at once is difficult, so researchers must pick and choose which to look at, and extrapolate. Now, he says, “you don't need to guess what is happening — you can see it”. © 2013 Nature Publishing Group

Keyword: Brain imaging
Link ID: 17922 - Posted: 03.19.2013

A clinical trial test of a vein-opening procedure for multiple sclerosis suggests it does not improve symptoms, and in a few patients symptoms worsened. The small pilot study was designed to test the safety and effectiveness of using balloons to unblock veins in the neck and chest of people with MS. Dr. Paolo Zamboni, left, and Dr. Robert Zivadinov have studied whether multiple sclerosis is triggered by vascular problems and have suggested it can be treated by using angioplasty to unblock vessels.Dr. Paolo Zamboni, left, and Dr. Robert Zivadinov have studied whether multiple sclerosis is triggered by vascular problems and have suggested it can be treated by using angioplasty to unblock vessels. Chronic cerebro-spinal venous insufficiency or CCSVI is a hypothesis put forward by Italian vascular surgeon Dr. Paolo Zamboni. He suspects that narrowed neck veins create a backup of blood that can lead to lesions in the brain and inflammation. On Friday, researchers at the University of Buffalo discussed the findings of their clinical trial involving 10 MS patients in an initial safety trial of the real and fake procedures and 20 who were randomized to receive treatment or a placebo. "All the outcomes that we looked at — which had to do with clinical disease, functional status, quality of life, cognition — there was no appreciable difference between the two arms," principal investigator Dr. Adnan Siddiqui, an assistant professor of neurosurgery at the University of Buffalo, said in an interview. When the investigators reviewed the MRI data, Siddiqu said they found new activity in patients who received the balloon angioplasty treatment. © CBC 2013

Keyword: Multiple Sclerosis
Link ID: 17914 - Posted: 03.18.2013

by Andy Coghlan Stimulating the brain with electrical signals can sharpen some of your faculties, but now it seems it can dim others at the same time. Transcranial electrical stimulation (TES), delivered by electrodes on the surface of the head, has been shown to double people's speed of learning. Now the first evidence has emerged that improvements in one aspect of learning might come at the expense of other abilities. Roi Cohen Kadosh of the University of Oxford, showed volunteers pairs of unfamiliar symbols. Each symbol had a secret numerical value, and the volunteers' task was to state – as quickly as possible while avoiding mistakes – which symbol in a pair had the bigger value. The correct answer was then displayed. Over six sessions in one week, it was possible to measure how quickly and efficiently the volunteers learned the value of each symbol. Second task In a second task, participants had to register which of each pair of symbols was physically larger, a measure of automatic thinking. "Automaticity is the skill of doing things without thinking about them, such as reading, driving or mounting stairs," says Cohen Kadosh, who conducted the experiment with Teresa Iucalano of the Stanford Cognitive and Systems Neuroscience Laboratory in Palo Alto, California. During the experiments, volunteers received TES to their posterior parietal cortex – vital for numerical learning – or their dorsolateral prefrontal cortex – vital for automaticity. Some unknowingly received a sham treatment. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 17877 - Posted: 03.09.2013

By James Gallagher Health and science reporter, BBC News It may be possible to use a patient's own skin to repair the damage caused by multiple sclerosis (MS), which is currently incurable, say researchers. Nerves struggle to communicate in MS as their insulating covering is attacked by the immune system - causing fatigue and damaging movement. Animal tests, described in the journal Cell Stem Cell, have now used modified skin cells to repair the insulation. Experts said there was an "urgent need" for such therapies. Just like electrical wires, nerves have insulation - but instead of plastic, the body uses a protein called myelin. However, diseases that result in damage to the myelin, including MS, leave the nerves exposed and electrical signals struggle to travel round the body. A team of scientists at the University of Rochester Medical Center, in the US, used advances in stem-cell research to attempt to repair the myelin. They took a sample of human skin cells and converted it into stem cells, which are capable of becoming any other type of cell in the body. The next step was to transform the stem cells into immature versions of cells in the brain that produce myelin. When these cells had been injected into mice born without any myelin it had had a significant effect, said researchers. BBC © 2013

Keyword: Multiple Sclerosis; Stem Cells
Link ID: 17780 - Posted: 02.09.2013

The number of children being diagnosed with epilepsy has dropped dramatically in the UK over the past decade, figures show. A study of GP-recorded diagnoses show the incidence has fallen by as much as half. Researchers said fewer children were being misdiagnosed, but there had also been a real decrease in some causes of the condition. Other European countries and the US had reported similar declines, they added. Epilepsy is caused when the brain's normal electrical activity result in seizures. Data from more than 344,000 children showed that the annual incidence of epilepsy has fallen by 4-9% year on year between 1994 and 2008. Overall the number of children born between 2003-2005 with epilepsy was 33% lower then those born in 1994-96. When researchers looked in more detail and included a wider range of possible indicators of an epilepsy diagnosis the incidence dropped by 47%. Correct diagnosis Better use of specialist services and increased caution over diagnosing the condition explains some, but not all, of the decline in the condition, the researchers reported in Archives of Diseases in Childhood. Introduction of vaccines against meningitis and a drop in the number of children with traumatic brain injuries, both of which can cause epilepsy, has probably also contributed to falling cases, they added. BBC © 2013

Keyword: Epilepsy; Development of the Brain
Link ID: 17751 - Posted: 02.04.2013

By R. Douglas Fields Imagine if your biggest health problem could be solved with the flip of a switch. Deep-brain stimulation (DBS) offers such a dramatic recovery for a range of neurological illnesses, including Parkinson's disease, epilepsy and major depression. Yet the metal electrodes implanted in the brain are too bulky to tap into intricate neural circuitry with precision and corrode in contact with tissue, so their performance degrades over time. Now neurophysiologists have developed a method of DBS that avoids these problems by using microscopic magnets to stimulate neurons. In experiments published in June 2012 in Nature Communications, neurophysiologist John T. Gale of the Cleveland Clinic and his colleague Giorgio Bonmassar, a physicist at Harvard Medical School and an expert on brain imaging, tested whether micromagnets (which are half a millimeter in diameter) could induce neurons from rabbit retinas to fire. They found that when they electrically energized a micromagnet positioned next to a neuron, it fired. In contrast to the electric currents induced by DBS, which excite neurons in all directions, magnetic fields follow organized pathways from pole to pole, like the magnetic field that surrounds the earth. The researchers found that they could direct the stimulus precisely to individual neurons, and even to particular areas of a neuron, by orienting the magnetic coil appropriately. “That may help us avoid the side effects we see in DBS,” Gale says, referring to, for instance, the intense negative emotions that are sometimes accidentally triggered when DBS is used to relieve motor problems in Parkinson's. © 2013 Scientific American

Keyword: Brain imaging; Parkinsons
Link ID: 17747 - Posted: 02.02.2013

by Carrie Arnold Studying the links between brain and behavior may have just gotten easier. For the first time, neuroscientists have found a way to watch neurons fire in an independently moving animal. Though the study was done in fish, it may hold clues to how the human brain works. "This technique will really help us understand how we make sense of the world and why we behave the way we do," says Martin Meyer, a neuroscientist at King's College London who was not involved in the work. The study was carried out in zebrafish, a popular animal model because they're small and easy to breed. More important, zebrafish larvae are transparent, which gives scientists an advantage in identifying the neural circuits that make them tick. Yet, under a typical optical microscope, neurons that are active and firing look much the same as their quieter counterparts. To see what neurons are active and when, neuroscientists have therefore developed a variety of indicators and dyes. For example, when a neuron fires, it is flooded with calcium ions, which can cause some of the dyes to light up. Still, the approach has limitations. Traditionally, Meyer explains, researchers would immobilize the head or entire body of a zebrafish larvae so that they could get a clearer picture of what was happening inside the brain. Even so, it was difficult to interpret neural activity for just a few neurons and over a short period of time. Researchers needed a better way to study the zebrafish brain in real time. © 2010 American Association for the Advancement of Science

Keyword: Brain imaging
Link ID: 17742 - Posted: 02.02.2013

The number of seizure patients in a northern Japanese fishing community devastated by the March 11, 2011 tsunami spiked in the weeks following the disaster, according to a Japanese study. The study, published in the journal Epilepsia, looked at 440 patient records from Kesennuma City Hospital, in a city that was devastated by the massive tsunami touched off by the 9.0 magnitude earthquake. Thirteen patients were admitted with seizures in the eight weeks after the disaster, but only one had been admitted in the two months before March 11. Previous research has linked stressful life-threatening disasters with an increased risk of seizures, but most case reports lacked clinical data with multiple patients. "We suggest that stress associated with life-threatening situations may enhance seizure generation," wrote lead author Ichiyo Shibahara, a staff neurosurgeon at Sendai Medical Center in northern Japan. But he added that stress itself is not a universal risk factor for seizures. "Most of the seizure patients had some sort of neurological disease before the earthquake," he said. His team examined medical records from patients admitted to the neurosurgery ward in the eight weeks before and after the March 11 disaster and compared them to the same time period each year between 2008 and 2010. In 2008, there were 11 seizure patients admitted between January 14 and May 15. In 2009, there were seven and in 2010, just four. © 2013 NBCNews.com

Keyword: Epilepsy; Stress
Link ID: 17705 - Posted: 01.22.2013

A strong family history of seizures could increase the chances of having severe migraines, says a study in Epilepsia journal. Scientists from Columbia University, New York, analysed 500 families containing two or more close relatives with epilepsy. Their findings could mean that genes exist that cause both epilepsy and migraine. Epilepsy Action said it could lead to targeted treatments. Previous studies have shown that people with epilepsy are substantially more likely than the general population to have migraine headaches, but it was not clear whether that was due to a shared genetic cause. The researchers found that people with three or more close relatives with a seizure disorder were more than twice as likely to experience 'migraine with aura' than patients from families with fewer individuals with seizures. Migraine with aura is a severe headache preceded by symptoms such as seeing flashing lights, temporary visual loss, speech problems or numbness of the face. Dr Melodie Winawer, lead author of the study from Columbia University Medical Centre, said the findings had implications for epilepsy patients. "Our study demonstrates a strong genetic basis for migraine and epilepsy, because the rate of migraine is increased only in people who have close (rather than distant) relatives with epilepsy." BBC © 2013

Keyword: Epilepsy; Pain & Touch
Link ID: 17657 - Posted: 01.07.2013

A simple eye test may offer a fast and easy way to monitor patients with multiple sclerosis (MS), medical experts say in the journal Neurology. Optical Coherence Tomography (OCT) is a scan that measures the thickness of the lining at the back of the eye - the retina. It takes a few minutes per eye and can be performed in a doctor's surgery. In a trial involving 164 people with MS, those with thinning of their retina had earlier and more active MS. The team of researchers from the Johns Hopkins University School of Medicine say larger trials with a long follow up are needed to judge how useful the test might be in everyday practice. The latest study tracked the patients' disease progression over a two-year period. Unpredictable disease Multiple sclerosis is an illness that affects the nerves in the brain and spinal cord causing problems with muscle movement, balance and vision. In MS, the protective sheath or layer around nerves, called myelin, comes under attack which, in turn, leaves the nerves open to damage. There are different types of MS - most people with the condition have the relapsing remitting type where the symptoms come and go over days, weeks or months. Usually after a decade or so, half of patients with this type of MS will develop secondary progressive disease where the symptoms get gradually worse and there are no or very few periods of remission. BBC © 2012

Keyword: Multiple Sclerosis; Vision
Link ID: 17639 - Posted: 12.27.2012

By Laura Sanders A new computer simulation of the brain can count, remember and gamble. And the system, called Spaun, performs these tasks in a way that’s eerily similar to how people do. Short for Semantic Pointer Architecture Unified Network, Spaun is a crude approximation of the human brain. But scientists hope that the program and efforts like it could be a proving ground to test ideas about the brain. Several groups of scientists have been racing to construct a realistic model of the human brain, or at least parts of it. What distinguishes Spaun from other attempts is that the model actually does something, says computational neuroscientist Christian Machens of the Champalimaud Centre for the Unknown in Lisbon, Portugal. At the end of an intense computational session, Spaun spits out instructions for a behavior, such as how to reproduce a number it’s been shown. “And of course, that’s why the brain is interesting,” Machens says. “That’s what makes it different from a plant.” Like a digital Frankenstein’s monster, Spaun was cobbled together from bits and pieces of knowledge gleaned from years of basic brain research. The behavior of 2.5 million nerve cells in parts of the brain important for vision, memory, reasoning and other tasks forms the basis of the new system, says Chris Eliasmith of the University of Waterloo in Canada, coauthor of the study, which appears in the Nov. 30 Science. © Society for Science & the Public 2000 - 2012

Keyword: Robotics
Link ID: 17557 - Posted: 12.01.2012

High-resolution real-time images show in mice how nerves may be damaged during the earliest stages of multiple sclerosis. The results suggest that the critical step happens when fibrinogen, a blood-clotting protein, leaks into the central nervous system and activates immune cells called microglia. "We have shown that fibrinogen is the trigger," said Katerina Akassoglou, Ph.D., an associate investigator at the Gladstone Institute for Neurological Disease and professor of neurology at the University of California, San Francisco, and senior author of the paper published online in Nature Communications. Multiple sclerosis, or MS, is thought to be an autoimmune disease in which cells that normally protect the body against infections attack nerve cells in the brain and spinal cord, often leading to problems with vision, muscle strength, balance and coordination, thinking and memory. Typically during MS, the immune cells destroy myelin, a protective sheath surrounding nerves, and eventually leading to nerve damage. The immune attack also causes leaks in the blood-brain barrier, which normally separates the brain from potentially harmful substances in the blood. "Dr. Akassoglou has focused on the role of the blood-brain barrier leak in MS and has discovered that leakage of the blood clotting protein fibrinogen can trigger brain inflammation," said Ursula Utz, Ph.D., M.B.A., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS). Microglia are cells traditionally thought to control immunity in the nervous system. Previous studies suggested that leakage of fibrinogen activates microglia.

Keyword: Multiple Sclerosis; Glia
Link ID: 17549 - Posted: 11.28.2012

Published by drrubidium Out-of-control libido or drug habit? Take Nervine. Nervous, excitable, wakeful, or restless? Take Nervine. Over-the-counter Nervine wasn't a wonder drug, just a cocktail of the oldest class of sedatives - inorganic bromides. Nervine contained the most commonly used bromides - sodium bromide (NaBr), potassium bromide (KBr), and ammonium bromide (NH4Br). These particular bromides were once so popular that only aspirin sold better. The use of bromides to treat "nerves" was so prevalent that 'bromide' entered the lexicon of common speech. Instead of "calm down", people were instructed to "take a bromide". Instead of calling someone a 'bore', the term 'bromide' was a used to denote "a commonplace or tiresome person". Bromides may owe their sedative effect to a family connection. The element bromine is in the same chemical family as the element chlorine – the halogens. Being a chemical family, chlorine and bromine have similar properties. Both form single, negatively charged ions (monovalent anions) via oxidation-reduction reactions - chloride (Cl-) and bromide (Br-). Chloride is found in nearly all of our cells, having its own set cell membrane-crossing highways (chlorine channel). The regulated flow of chloride (as hydrated chloride) across neuron membranes is key to communication between neurons. Being family and all, bromide (as hydrated bromide) can travel along chloride's highways. But hydrated bromide is a teeny bit smaller than hydrated chloride, allowing hydrated bromide to get into cells faster than hydrated chloride. A flood of anions, such as bromide or chloride, into a neuron makes it more negative than it would be at rest, a state called 'hyperpolarization'. It's hard for other neutrons to stimulate - talk to - hyperpolarized neurons. Less neuron stimulation can translate to a feeling of calm. Thirty-Seven Copyright © 2012

Keyword: Drug Abuse
Link ID: 17535 - Posted: 11.26.2012

A substance made by the body when it uses fat as fuel could provide a new way of treating epilepsy, experts hope. Researchers in London who have been carrying out preliminary tests of the fatty acid treatment, report their findings in Neuropharmacology journal. They came up with the idea because of a special diet used by some children with severe, drug resistant epilepsy to help manage their condition. The ketogenic diet is high in fat and low in carbohydrate. The high fat, low carbohydrate diet is thought to mimic aspects of starvation by forcing the body to burn fats rather than carbohydrates. Although often effective, the diet has attracted criticism, as side-effects can be significant and potentially lead to constipation, hypoglycaemia, retarded growth and bone fractures. By pinpointing fatty acids in the ketogenic diet that are effective in controlling epilepsy, researchers hope they can develop a pill for children and adults that could provide similar epilepsy control without the side-effects. In early trials, the scientists, from Royal Holloway and University College London, say they have identified fatty acids that look like good candidates for the job. They found that not only did some of the fatty acids outperform a regular epilepsy medication called valproate in controlling seizures in animals, they also had fewer side-effects. BBC © 2012

Keyword: Epilepsy; Obesity
Link ID: 17533 - Posted: 11.24.2012