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WEST LAFAYETTE, Ind. – Purdue University researchers have shown that extremely thin carbon fibers called "nanotubes" might be used to create brain probes and implants to study and treat neurological damage and disorders. Probes made of silicon currently are used to study brain function and disease but may one day be used to apply electrical signals that restore damaged areas of the brain. A major drawback to these probes, however, is that they cause the body to produce scar tissue that eventually accumulates and prevents the devices from making good electrical contact with brain cells called neurons, said Thomas Webster, an assistant professor of biomedical engineering. New findings showed that the nanotubes not only caused less scar tissue but also stimulated neurons to grow 60 percent more fingerlike extensions, called neurites, which are needed to regenerate brain activity in damaged regions, Webster said.

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: 4771 - Posted: 06.24.2010

By Carolyn Y. Johnson They have long been dismissed as the brain’s Bubble Wrap, packing material to protect precious cells that do the real work of the mind. But glial cells — the name literally means “glue’’ — are now being radically recast as neuroscientists explore the role they play in disease and challenge longstanding notions about how the brain works. More than a century ago, scientists proposed the “neuron doctrine,’’ a theory that individual brain cells called neurons are the main players in the nervous system. It became an underpinning of modern neuroscience and led to major advances in understanding the brain, but it has become increasingly apparent that the other 85 percent of brain cells, glia, do more than just housekeeping. “In a play in a theater, it’s not just the actors on the stage, but the whole ensemble that is critical for that production to be perfect,’’ said Philip Haydon, chairman of the neuroscience department at Tufts University School of Medicine. “The players on the stage are neurons, but if you don’t have every person backstage, you don’t have a production, and what we’re now realizing is this whole support cast [of glia] is essential for normal brain function.’’ Haydon became curious about glia nearly two decades ago as an unintentional consequence of an experiment. He killed neurons in a dish of brain cells and left the glia, expecting to see the chemical signals that neurons use to communicate with one another disappear. To his surprise, the signals did not stop — suggesting the glia were not passive. © 2010 NY Times Co

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 13: Memory, Learning, and Development
Link ID: 14124 - Posted: 06.24.2010

by Carl Zimmer Some of the common words we use are frozen mistakes. The term influenza comes from the Italian word meaning “influence”—an allusion to the influence the stars were once believed to have on our health. European explorers searching for an alternate route to India ended up in the New World and uncomprehendingly dubbed its inhabitants indios, or Indians. Neuroscientists have a frozen mistake of their own, and it is a spectacular blunder. In the mid-1800s researchers discovered cells in the brain that are not like neurons (the presumed active players of the brain) and called them glia, the Greek word for “glue.” Even though the brain contains about a trillion glia—10 times as many as there are neurons—the assumption was that those cells were nothing more than a passive support system. Today we know the name could not be more wrong. Glia, in fact, are busy multitaskers, guiding the brain’s development and sustaining it throughout our lives. Glia also listen carefully to their neighbors, and they speak in a chemical language of their own. Scientists do not yet understand that language, but experiments suggest that it is part of the neurological conversation that takes place as we learn and form new memories. If you had to blame one thing for the mistaken impression about glia, it would have to be electricity. The 18th-century physiologist Luigi Galvani discovered that if he touched a piece of electrified metal to an exposed nerve in a frog’s leg, the leg twitched. He and others went on to show that a slight pulse of electricity moving through the metal to the nerve was responsible. For two millennia physicians and philosophers had tried to find the “animal spirits” that moved the body, and Galvani discovered that impetus: It was the stuff of lightning.

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: 13188 - Posted: 06.24.2010

By Nathan Seppa Mutations in two genes, IDH1 and IDH2, might provide markers that enable doctors to discern malignant from benign brain tumors and catch some cancers early, scientists report in the Feb. 19 New England Journal of Medicine. The study adds to a growing list of molecular clues that doctors may ultimately use to diagnosis and treat cancers, says study coauthor D. Williams Parsons, a pediatric oncologist and Howard Hughes Medical Institute investigator at Johns Hopkins University in Baltimore. Doctors diagnose nearly 200,000 brain cancers each year in the United States. Most get their start elsewhere in the body and spread to the brain. But in about 22,000 of these patients, the cancer originates in the brain or central nervous system. These primary brain tumors are most often gliomas — clusters of tumor cells that derive from the brain’s glial cells. Gliomas vary in virulence from benign (grade 1) to fast-growing and rapidly lethal (grade 4). The IDH genes are so-named because they encode an enzyme called isocitrate dehydrogenase. While the role of the enzyme is poorly understood, the mutations in IDH genes attracted interest after turning up last year in brain tumors but not in other cancer tissues. In the new study, the researchers tested samples of benign and cancerous primary brain tumors removed from 445 people and from tumors obtained from 494 others who had cancers of the colon, prostate, pancreas, breast, stomach, ovary or blood (leukemia). © Society for Science & the Public 2000 - 2009

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: 12574 - Posted: 06.24.2010

By Tina Hesman Saey Two groups of researchers — one at MIT, the other at Harvard — have shown that astrocytes get the blood pumping to parts of the brain that are thinking hard. These cells may use blood flow and other tricks to rev up communication between neurons or slow it down, and may even play a role in storing information. The findings indicate that astrocytes are not just supporting actors for neurons; they deserve recognition as true costars. “Astrocytes are typically forgotten,” says Venkatesh Murthy, leader of the Harvard group, but they “are right in the thick of things.” Neurons have typically gotten the most attention from researchers because they are the brain cells that do all the thinking. But neurons cohabit the brain with a class of cells called glia, which means “glue” in Greek. Glia outnumber neurons in the human brain by a factor of 10 to one, and astrocytes are the most abundant type of glial cell. The view of astrocytes has changed slowly over the past decade. Astrocytes were once thought to do little more than hold the brain together and they were largely ignored. In recent years, though, scientists have learned that the star-shaped cells have a hand in guiding connections between neurons and controlling levels of chemical messengers in the brain. But those activities were viewed mainly as supporting roles. Now their central function in controlling blood flow indicates that astrocytes deserve higher billing. Without astrocytes, in fact, one of the most powerful tools of neuroscience — functional MRI — would not be possible. © Society for Science & the Public 2000 - 2008

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: 11810 - Posted: 06.24.2010

By Nikhil Swaminathan Nearly a century after the discovery of strange star-shaped cells in the brain, scientists say they have finally begun to unravel their function. Researchers from the Massachusetts Institute of Technology report in Science that it appears astrocytes—named for their stellar form—provide nerve cells (neurons) with the energy they need to function and communicate with one another, by signaling blood to deliver the cell fuels glucose and oxygen to them. When astrocytes were first discovered, it was believed that they were bit players in the brain. But the new research indicates they may actually be major operators that, when out of whack, may help trigger mental disorders such as autism and schizophrenia. Study coauthor Mriganka Sur, a neuroscientist and head of MIT's Department of Brain and Cognitive Science, says his team saw astrocytes in action while examining brain activity in ferrets. Using technology called two-photon microscopy, Sur and his colleagues observed that astrocytes in the visual cortex (part of the brain responsible for vision) activated and blood flow increased to nerve cells just seconds after the neurons had fired or sent out signals. © 1996-2008 Scientific American Inc.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 11733 - Posted: 06.24.2010

ST. PAUL, Minn. - On the slaughterhouse floor at Quality Pork Processors Inc. is an area known as the "head table," but not because it is the place of honor. It is where workers cut up pigs' heads and then shoot compressed air into the skulls until the brains come spilling out. But now the grisly practice has come under suspicion from U.S. health authorities. Over eight months from last December through July, 11 workers at the Austin, Minn., plant — all of them employed at the head table — developed numbness, tingling or other neurological symptoms, and some scientists suspect inhaled airborne brain matter may have somehow triggered the illnesses. The use of compressed air to remove pig brains was suspended at Quality Pork earlier this week while authorities try to get to the bottom of the mystery. "I'm still in shock, I guess," said 37-year-old Susan Kruse, who worked at the plant for 15 years until she got too weak to do her job last February. "But it was very surprising to hear that there was that many other people that have gotten this." Five of the workers — including Kruse, who has been told she may never work again — have been diagnosed with chronic inflammatory demyelinating polyneuropathy, or CIDP, a rare immune disorder that attacks the nerves and produces tingling, numbness and weakness in the arms and legs, sometimes causing lasting damage. © 2007 The Associated Press.

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 11: Emotions, Aggression, and Stress
Link ID: 11062 - Posted: 06.24.2010

Declan Butler Two children with a common neurodegenerative disease are seeing early signs of success from a pioneering gene-therapy treatment, researchers report this week. The results raise hopes for a treatment for adrenoleukodystrophy (ALD), and, the researchers add, mark the first successful use of an attenuated HIV virus to carry a therapeutic gene into a patient’s cells. HIV is a promising vector for transferring corrective genes into a host — it can penetrate directly into cell nuclei, making it a theoretically efficient way to introduce new genetic material. But until now it hadn’t been proven in a clinical setting. This early success potentially opens the door to better treatments for many other diseases involving the bone marrow and blood cells, such as leukaemia, thalassemia and sickle-cell disease, the researchers say. The results, from two 7-year-old Spanish children with ALD, were announced on Sunday 28 October at the fifteenth Congress of the European Society of Gene and Cell Therapy in Rotterdam, the Netherlands ALD is caused by a mutation on the X chromosome. This mutation causes degradation of the insulating sheaths that surround neurons and allow them to signal properly. The condition was made famous by Lorenzo's Oil , the Hollywood film outlining one family’s fight to help their son. The most severe, cerebral form of ALD affects one in 17,000 people, with two-thirds of sufferers being children. It progresses slowly at first, but if no bone-marrow transplant is available it can quickly progress to cause brain damage and death. © 2007 Nature Publishing Group

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 10905 - Posted: 06.24.2010

Electrical impulses foster myelination, the insulation process that speeds communication among brain cells, report researchers at two institutes of the National Institutes of Health. “This finding provides important information that may lead to a greater understanding of disorders such as multiple sclerosis that affect myelin, as well as a greater understanding of the learning process,” said Duane Alexander, M.D., Director of the NICHD. The study appears in the March 16 Neuron and was conducted by researchers at the National Institute of Child Health and Human Development and the National Cancer Institute. Neurons — specialized cells of the brain and nervous system — communicate via a relay system of electrical impulses and specialized molecules called neurotransmitters, explained the study’s senior author, R. Douglas Fields, Ph.D., Head of NICHD’s Nervous System Development and Plasticity Section. A neuron generates an electrical impulse, causing the cell to release its neurotransmitters, he said. The neurotransmitters, in turn, bind to nearby neurons. The recipient neurons then generate their own electrical impulses and release their own neurotransmitters, triggering the process in still more neurons, and so on. Neurons conduct electrical impulses more efficiently if they are covered with an insulating material known as myelin, Dr. Fields added. Layers of myelin are wrapped around the fiber-like projections of neurons like electrical tape wrapped spiral-fashion around an electrical cable. Human beings are born with comparatively little myelin, and neurons become coated with the material as they develop. Moreover, mental activity appears to influence myelination, Dr Fields said. For example, neglected children have less myelin in certain brain regions than do other children.

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 8664 - Posted: 06.24.2010

— Researchers have discovered that astrocytes — brain cells once thought to be little more than a component of the supportive scaffold for neurons — may actually play a starring role in triggering the maturation and proliferation of adult neural stem cells. The studies also suggest that growth factors produced by astrocytes may be critical in regenerating brain or spinal tissue that has been damaged by trauma or disease. The discovery that astrocytes are important for neuronal maturation, or neurogenesis, was reported in the May 2, 2002, issue of the journal Nature by Howard Hughes Medical Institute investigator Charles F. Stevens and colleagues Fred H. Gage and HHMI research associate Hong-jun Song at The Salk Institute. Neurons are the key information-carrying cells in the central nervous system. All neurons, as well as other types of brain cells, arise from immature neural stem cells, which have the potential to develop into any kind of cell in the central nervous system. ©2002 Howard Hughes Medical Institute

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: 2005 - Posted: 06.24.2010

Tampa, FL — Researchers at the University of South Florida's Roskamp Institute have identified an immune molecule, CD40, on the surface of neurons that appears to promote both neuron development and protection. The finding is a first step in defining the role of CD40 in the brain at different stages of life and evaluating its usefulness in helping neurons survive. The study is published in the latest March issue of the journal European Molecular Biology Organization. In the bloodstream, the interaction between the protein receptor CD40 and another protein, CD40 ligand (CD40L), allows white cells to trigger antibody production and to activate cellular immunity. This immune response helps neutralize foreign invaders, such as bacteria and viruses. However, in an earlier study, the USF reseachers found that when this same CD40-CD40L signaling system is triggered in the brain, the immune response can cause microglia damage to neurons.

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: 1796 - Posted: 06.24.2010

By Tina Hesman Saey Scientists have discovered the true identity of a contagious form of cancer that is killing Tasmanian devils. The cancer, called devil facial tumor disease, stems from cells that normally insulate nerve fibers, a new study shows. Genetic analysis of tumors taken from infected devils in different parts of Tasmania reveals that these insulating cells, known as Schwann cells, became cancerous in a single Tasmanian devil and have since passed to other devils, an international group of researchers reports in the Jan. 1 Science. Previously, scientists had suspected that a virus might be the source of the infection, but the new study confirms that cancer cells themselves are transmitted from devil to devil. Knowing the origin of the contagious tumors could help conservationists diagnose the disease more accurately and may eventually lead to a vaccine that would target tumor proteins, says Katherine Belov, a geneticist at the University of Sydney who was not involved with the project. A vaccine against the facial tumor disease, “while now pie in the sky, in 10 years might not be,” says Gregory Hannon, a Howard Hughes Medical Institute investigator at Cold Spring Harbor Laboratory on Long Island, N.Y. “Ten years might be enough time” to save the devils from extinction, he says. © Society for Science & the Public 2000 - 2010

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: 13620 - Posted: 06.24.2010

By Cassandra Willyard Think back to high school biology. Remember the long, stringy neurons that make up your nervous system? You probably learned that these cells communicate by sending a chemical message across the small gap between them, called a synapse. That's still true, but new research shows that certain brain cells bypass the synapse altogether. Instead, they communicate by spraying a cloud of neurotransmitters into the spaces between cells, blanketing nearby neurons. A team of Hungarian researchers at the University of Szeged made the discovery by examining a type of neuron called a neurogliaform cell. These cells are common in the brain's cortex, a region that plays a key role in many functions, including memory, attention, awareness, and language. Studies have shown that neurogliaform cells can inhibit the firing of other brain cells by releasing a neurotransmitter called GABA (gamma-aminobutyric acid), which typically transmits messages across synapses. But some studies have suggested that GABA can diffuse into the extracellular space as well, where it carries messages between neurons not connected via synapses. To create enough ambient GABA for this to happen, however, scientists speculated that many neurons would have to fire at once. The researchers set out to test this idea. The output end, or axon, of a normal neuron is typically long and stringy. But when the Hungarian team used electron and light microscopes to examine brain tissue from rats and humans, they found that neurogliaform cells have bushy axons with many branches. These bushy axons are densely populated with sites where GABA can be released into the extracellular space, the team found. Elsewhere in the brain this occurs mainly at synapses, but only 11 of the 50 release sites examined in neurogliaform cells corresponded to a synapse, the researchers report today in Nature. © 2009 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 13417 - Posted: 06.24.2010

By Andrew Koob Andrew Koob received his Ph.D. in neuroscience from Purdue University in 2005, and has held research positions at Dartmouth College, the University of California, San Diego, and the University of Munich, Germany. He's also the author of The Root of Thought, which explores the purpose and function of glial cells, the most abundant cell type in the brain. Mind Matters editor Jonah Lehrer chats with Koob about why glia have been overlooked for centuries, and how new experiments with glial cells shed light on some of the most mysterious aspects of the mind. LEHRER: Your new book, The Root of Thought, is all about the power of glial cells, which actually make up nearly 90 percent of cells in the brain. What do glial cells do? And why do we have so many inside our head? KOOB: Originally, scientists didn't think they did anything. Until the last 20 years, brain scientists believed neurons communicated to each other, represented our thoughts, and that glia were kind of like stucco and mortar holding the house together. They were considered simple insulators for neuron communication. There are a few types of glial cells, but recently scientists have begun to focus on a particular type of glial cell called the 'astrocyte,' as they are abundant in the cortex. Interestingly, as you go up the evolutionary ladder, astrocytes in the cortex increase in size and number, with humans having the most astrocytes and also the biggest. Scientists have also discovered that astrocytes communicate to themselves in the cortex and are also capable of sending information to neurons. Finally, astrocytes are also the adult stem cell in the brain and control blood flow to regions of brain activity. Because of all these important properties, and since the cortex is believed responsible for higher thought, scientists have started to realize that astrocytes must contribute to thought. © 1996-2009 Scientific American Inc.

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: 13412 - Posted: 06.24.2010

ROCHESTER, N.Y., (UPI) -- U.S. researchers say they've discovered brain cells called astrocytes are what distinguish the human brain from that of other animals. "Studies in rodents show that non-neuronal cells are part of information processing," said Dr. Maiken Nedergaard of the University of Rochester Medical Center, who led the research team. "And our study suggests that astrocytes are part of the higher cognitive functioning that defines who we are as humans." The scientists noted there are 10 times as many astrocytes in the brain than the neurons that send electrical signals. Medical student Nancy Ann Oberheim, first author of the study, said human astrocytes signals are faster, bigger and more complex than those found in mice and rats. The researchers discovered new types of astrocytes, and also determined astrocytes use calcium, rather than electrical signals, to communicate with neurons. The research team reported astrocytes send much slower signals that do neurons, but are just as important in the basic working of the brain. The study that included scientists from New York Medical College and the University of Washington appears in the Journal of Neuroscience. © 2009 United Press International, Inc.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 12695 - Posted: 06.24.2010

Roxanne Khamsi New evidence adds weight to the theory that one of the most deadly forms of brain cancer, called malignant glioma, is caused when stem cells deep within the brain begin to proliferate abnormally, researchers have announced. Special receptors on the surfaces of these cells trigger cancerous cell division in response to a particular growth hormone, the team's experiments in mice reveal. Absence of this hormone caused such tumours to shrink, they discovered, raising hopes for a potential treatment. When diagnosed with malignant gliomas, the sufferer typically has just 14 months to live. There is currently no effective treatment for the fast-spreading illness. Arturo Alvarez-Buylla at the University of California in San Francisco, US, and colleagues conducted post-mortem examinations of the brains of three people without the illness. Chemical tests on nerve stem-cells in a deep region of the brain, known as the sub-ventricular zone, revealed the existence of receptors for a growth hormone known as PDGF on the cell surfaces. The PDGF receptors on these stem cells are the same as those found in cells from malignant brain tumours, comments Charles Stiles of the Dana-Farber Cancer Institute in Boston, Massachusetts, US. He says this strengthens the argument that malignant gliomas result when brain stem cells regenerate abnormally. © Copyright Reed Business Information Ltd.

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: 9152 - Posted: 06.24.2010

A particularly aggressive form of brain tumor called a glioma may be vulnerable to a drug currently used to treat Crohn's disease, according to a new study in mice. The finding is good news to scientists looking for better treatment options for a cancer that is almost always fatal. The drug exploits a weakness of glioma cells. While most cells take in a necessary amino acid called cystine through a variety of pathways, a team led by Harald Sontheimer, a neuroscientist with the University of Alabama at Birmingham, has discovered that glioma cells have only one mechanism for grabbing the amino acid. Earlier studies elsewhere found that cystine intake in leukemia cells is impaired by sulfasalazine, a drug used to treat diseases such as Crohn's, which causes inflammation of the intestinal tract. So, Sontheimer and colleagues wondered if the drug would cut off the cystine supply to glioma tumors. To test the theory, the researchers first injected mice with malignant human glial tissue. After the tissue developed into tumors, the team divided the mice into three groups. Two groups got sulfasalazine for either 1 or 3 weeks, and a control group received saline. Within 48 hours of receiving the drug, mice in the sulfasalazine group showed biochemical signs that glioma cells were affected. And within a matter of weeks, the size of their tumors had shrunk dramatically. The drug also increased the animals' survival rate. Mice in the control group showed no improvement, the team reports 27 July in the Journal of Neuroscience. Copyright © 2005 by the American Association for the Advancement of Science

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: 7695 - Posted: 06.24.2010

Roxanne Khamsi Can a controversial medicine called Lorenzo's oil really reduce the risk of developing a rare brain disease? After years of hope and provisional evidence, experts are publishing scans from children who started this therapy more than a decade ago. They say the positive results will quiet sceptics and prove the oil's worth. In 1984, Augusto and Michaela Odone learned that their son, Lorenzo, suffered from a genetic disorder known as adrenoleukodystrophy, or ALD. The prognosis was frightening: children diagnosed with ALD experience neurological deterioration and typically die from the illness within a few years. Faced with a lack of treatment options for their son, the Odones began pouring over books in the library for more information. They learned that ALD is related to an abnormal accumulation of very-long-chain fatty acids, particularly in the nervous system of the body. Although they tried to cut these fatty acids from their son's diet, his body continued producing them. The literature convinced them that giving their son a different fatty acid, an oily liquid known as oleic acid, would inhibit the synthesis of long chains of saturated fats. It works simply by keeping enzymes busy making chains of unsaturated fats instead. The Odones later improved their formula by using a modified form of rapeseed oil, which seems to keep the enzymes even busier. Their medicine, which improved the health of their ailing son and inspired a Hollywood movie in the early 1990s, became known as 'Lorenzo's oil'. ©2005 Nature Publishing Group

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: 7623 - Posted: 06.24.2010

NEW ORLEANS --Glial cells once had a reputation as the support staff for neurons, the real movers and shakers in the nervous system. In recent years, however, researchers have gleaned hints that glia, which comprise about 90% of the cells in the brain, do more than just maintenance work. New findings presented here last week at the annual meeting of the Society for Neuroscience suggest that in the crucial task of building synapses--the contact points that allow neurons to talk to one another--glia may even run the show. The study firms up earlier evidence that glial cells called astrocytes instruct neurons to make synapses and identifies the first extracellular signal known to spur synapse formation in the brain. "That's a pretty big deal," says Michael Ehlers, a neuroscientist at Duke University in Durham, North Carolina. A clue that glia might be the source of the signal to build synapses came in 2001, when Ben Barres and colleagues at Stanford University reported that lab-grown rat neurons make more synapses in the presence of astrocytes (Science , 26 January 2001, p. 657). To hunt for the chemical messenger, postdocs Karen Christopherson and Erik Ullian in Barres's lab grew astrocytes in culture and filtered the solution bathing the cells before adding it to neurons. To their surprise, these experiments indicated that the chemical that spurs synapse building was a whopper--more than 300 kilodaltons. Copyright © 2003 by the American Association for the Advancement of Science.

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: 4555 - Posted: 06.24.2010

For the brain to stay online, it needs quick delivery of oxygen and energy. Now, neuroscientists have identified the brain cells that order blood supply for humming parts of the brain. Understanding the link between brain activity and changes in blood flow is crucial to further improve clinical brain scans, such as functional magnetic resonance imaging (MRI), which chart changes in brain activity via measurements of blood flow. Once dismissed as mere scaffolding in the brain, starlike cells called astrocytes are stepping into the limelight. Astrocytes are far more abundant than the electrically powered neurons, and each one features entangled fingerlike processes connected to more than a thousand nerve cells. Positioned close to the neuronal chat sites, the synapses, astrocytes sense neuronal activity and can even influence it, a fact that researchers have come to appreciate in recent years. Astrocytes are also hooked up to the fine network of capillaries that feed neurons, but their interaction with blood vessels has remained mysterious. Copyright © 2002 by the American Association for the Advancement of Science.

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: 3093 - Posted: 06.24.2010