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October 23, 2008, 9:04 PM CT

BG-12 significantly reduced brain lesions in multiple sclerosis

BG-12 significantly reduced brain lesions in  multiple sclerosis
Cambridge, MA October 23, 2008 Biogen Idec (NASDAQ: BIIB) today announced the publication of Phase IIb data showing that a 240 mg three-times-daily dose of the company's novel oral compound, BG-12 (BG00012, dimethyl fumarate), reduced the number of new gadolinium enhancing (Gd+) lesions by 69 percent in patients with relapsing-remitting multiple sclerosis (MS) when in comparison to therapy with placebo (p<0.0001). The data also showed a 53 percent reduction in the mean number of T1-hypointense lesions and a 44 percent reduction in cumulative new Gd+ lesions in patients treated with BG-12 in comparison to therapy with placebo. The presence of Gd+ lesions is thought to indicate continuing inflammatory activity within the central nervous system. T1-hypointense lesions are linked to significant breakdown and loss of brain tissue. An ad hoc analysis conducted during the study showed a decrease in the likelihood of Gd+ lesions evolving into T1-hypointense lesions (black holes), warranting further clinical study into the potential neuroprotective and anti-inflammatory effects of BG-12. These results have been reported in the October 25th issue of The Lancet

BG-12 is the first compound that has been shown to activate the Nrf2 transcriptional pathway, which prior studies have shown defends against oxidative-stress induced neuronal death, protects the blood-brain barrier, and supports maintenance of myelin integrity in the central nervous system.........

Posted by: Daniel      Read more         Source


October 23, 2008, 5:35 AM CT

Seeing a brain as it learns to see

Seeing a brain as it learns to see
A brain isn't born fully organized. It builds its abilities through experience, making physical connections between neurons and organizing circuits to store and retrieve information in milliseconds for years afterwards.

Now that process has been caught in the act for the first time by a Duke University research team that watched a nave brain organize itself to interpret images of motion.

"This is the first time that anyone has been able to watch as visual experience selectively shapes the functional properties of individual neurons," said David Fitzpatrick, professor of neurobiology and director of the Duke Institute for Brain Sciences. "These results emphasize just how important experience is for the early development of brain circuits." The group's findings appear online Oct. 22 in the journal Nature

Using an advanced imaging system that can see changes in calcium levels within individual neurons as an indication of electrical activity, the team has been able to see inside the brain of a one-month old ferret as it opened its eyes for the first time and learned how to interpret moving images.

They watched the brain learning how to see. As a ferret learned to discriminate one pattern of motion from another over the course of a few hours, the scientists could see large numbers of individual neurons in the visual cortex develop specific responses and become organized into functional assemblies called cortical columns. Additional experiments confirmed that the changes were dependent on the neurons being activated by the animal's experience with moving visual images.........

Posted by: Daniel      Read more         Source


October 20, 2008, 5:45 AM CT

How neuronal activity leads to Alzheimer's protein cleavage

How neuronal activity leads to Alzheimer's protein cleavage
Amyloid precursor protein (APP), whose cleavage product, amyloid-b (Ab), builds up into fibrous plaques in the brains of Alzheimer's disease patients, jumps from one specialized membrane microdomain to another to be cleaved, report Sakurai et al.

Eventhough there is no definitive evidence that Ab plaques are the direct cause of Alzheimer's disease, there is much circumstantial evidence to support this. And working on this hypothesis, researchers are investigating just how the plaques form and what might be done to stop or reverse their formation.

APP, a protein of unknown function, is membrane associated and concentrates at the neuronal synapse. Certain factors such as high cellular cholesterol and increased neuronal or synaptic activity are known to drive APP cleavage, and Sakurai and his colleagues' paper pulls these two modes of Ab regulation together.

APP associates with membrane microdomains high in cholesterols (lipid rafts). These lipid rafts can also contain the enzyme necessary for APP cleavage, BACE. Synaptic activity is known to involve a very different type of membrane microdomain high in an excytosis-promoting factor called syntaxin. Sakurai et al. now show that eventhough APP preferentially associates with syntaxin microdomains, upon neuronal stimulation APP instead associates with microdomains that contain BACE.........

Posted by: Daniel      Read more         Source


October 16, 2008, 11:02 PM CT

High-altitude climbing causes subtle loss of brain cells and motor function

High-altitude climbing causes subtle loss of brain cells and motor function
Mount Everest
A study of professional mountain climbers has shown that high-altitude exposure can cause subtle white and grey matter changes to the area of the brain involved in motor activity, as per the recent issue of the European Journal of Neurology

Italian scientists took MRI scans of nine world-class mountain climbers, who had been climbing for at least 10 years, before and after expeditions to Mount Everest (8,848 metres) and K2 (8,611 metres) without an oxygen supply. They compared their MRI brain scans with 19 age and sex matched healthy control subjects.

Both the climbers and controls were carefully checked to exclude the presence of any major systemic, psychiatric or neurological illnesses. None of the control group subjects had any history of high-altitude exposure over 3,000 metres.

The results demonstrated that the climbers showed a reduction in both the density and volume of white matter in the left pyramidal tract, near the primary and supplementary motor cortex, when their baseline measurements were compared with the control group.

And when the scientists compared the before and after scans for the climbers, they also found a reduction in the density and volume of grey matter in the left angular gyrus.

"The aim of our study was to measure the quantitative loss of white and grey matter, using voxel-based morphometry, which takes spatial, unbiased MRI measurements independent of the operator" explains lead author Dr Margherita Di Paola from the Neuroimaging Laboratory at the IRCCS Fondazione Santa Lucia in Rome.........

Posted by: Daniel      Read more         Source


October 16, 2008, 11:01 PM CT

When a light goes on during thought processes

When a light goes on during thought processes
Individual and double action potentials can be recorded optically using a genetic calcium indicator that colours the cells in the brain of a living mouse.

Image: Max Planck Institute for Medical Research
A nerve cell is a major hub for the exchange of valuable information. The nose, eyes, ears, and other sense organs perceive our environment through various antennae known as receptors. The numerous stimuli are then passed on to the neurons. All of this information is collected, processed, and finally transferred to specific brain centers at these hubs - the human brain consists of almost 100 billion nerve cells. The nerve cell uses a special means of transport for this purpose: the action potential which codes the information, thus enabling communication between the nerve cells.

Calcium as the starting gun.

An action potential of this kind is an electrical excitation and arises when our nerve cells receive the information via a stimulus: the voltage across the cell membrane of the neuron changes and various ion channels open and close in a very specialized manner. Shortly before the nerve cell forwards the information via the stimulus, calcium ions pour into the nerve cell, acting as the starting gun for the flow of data from one neuron to the next.

In the past, action potential was measured and rendered visible using microelectrodes. However, this method only enabled the monitoring of a limited number of cells engaged in the process of communication. Moreover, researchers were unable to record neuronal communication in a clearly identifiable way over a longer period or in freely moving animals using this method.........

Posted by: Daniel      Read more         Source


October 15, 2008, 5:52 PM CT

Brain-nourishing molecule may predict schizophrenia relapse

Brain-nourishing molecule may predict schizophrenia relapse
A factor that helps optimize brain formation and function may also provide clues about whether patients suffering with schizophrenia are headed toward relapse, scientists say.

Over the next two- and one-half years, they are regularly measuring levels of brain-derived neurotrophic factor, or BDNF, in the blood of patients with schizophrenia to see if the pattern of their rise and fall is a good indicator that patients are headed for trouble, say Medical College of Georgia researchers.

"If you had something that would give you a better inkling that somebody is going to get ill, that would be extraordinarily helpful," says Dr. Peter S. Buckley, schizophrenia specialist who chairs the Department of Psychiatry and Health Behavior in the MCG School of Medicine. "It's a little bit of a shot in the dark, but the payoff would be huge," he says of the study that piggybacks on another federally-funded study looking at whether injectable medicine, rather than tablets, can help deter relapses.

Not taking their medicines as prescribed is a big reason patients relapse but science has already shown that BDNF levels can start dropping even when they do, says Dr. Anilkumar R. Pillai, MCG neuroscientist who studies BDNF and other cell-nourishing trophic factors. That drop likely indicates the drug is becoming less effective and a relapse is imminent, the scientists say.........

Posted by: Daniel      Read more         Source


October 14, 2008, 10:17 PM CT

Searching the Internet increases brain function

Searching the Internet increases brain function
UCLA researchers have observed that for computer-savvy middle-aged and elderly adults, searching the Internet triggers key centers in the brain that control decision-making and complex reasoning. The findings demonstrate that Web search activity may help stimulate and possibly improve brain function.

The study, the first of its kind to assess the impact of Internet searching on brain performance, is currently in press at the American Journal of Geriatric Psychiatry and will appear in an upcoming issue.

"The study results are encouraging, that emerging computerized technologies may have physiological effects and potential benefits for middle-aged and elderly adults," said principal investigator Dr. Gary Small, a professor at the Semel Institute for Neuroscience and Human Behavior at UCLA who holds UCLA's Parlow-Solomon Chair on Aging. "Internet searching engages complicated brain activity, which may help exercise and improve brain function." .

As the brain ages, many structural and functional changes occur, including atrophy, reductions in cell activity, and increases in deposits of amyloid plaques and tau tangles, which can impact cognitive function.

Small noted that pursuing activities that keep the mind engaged may help preserve brain health and cognitive ability. Traditionally, these include games such as crossword puzzles, but with the advent of technology, researchers are beginning to assess the influence of computer use including the Internet.........

Posted by: Daniel      Read more         Source


October 14, 2008, 8:25 PM CT

Alzheimer's disease and blood pressure

Alzheimer's disease and blood pressure
A new study (http://dx.doi.org/10.1016/j.bihy.2008.04.006) published in Bioscience Hypotheses (http://www.elsevier.com/locate/issn/1756-2392), a recently launched Elsevier journal, proposes that some people suffering from Alzheimer's disease experience a reduction in their hypertension because of cognitive decline.

Publications relating to dementia and blood pressure have been evaluated by the paper's author Dr Sven Kurbel of the Osijek Medical Faculty in Croatia. The cognitive problems suffered by some Alzheimer's patients have previously been put down to low blood pressure (arterial hypotension). The hypothesis put forward by Dr Kurbel is that the opposite is true. He suggests that as the patient's memory fails, they forget the causes of anxiety and worry that was causing high blood pressure: failing memory causes hypotension, not visa versa.

High blood pressure itself is a cause of disease, including strokes, so paradoxically, Dr. Kurbel's hypothesis suggests, therapys which alleviate memory loss could affect other causes of illness. If this hypothesis is correct it could have a significant effect on the therapy of conditions such as metabolic syndrome, which involves increased weight and high blood pressure. Dr. Kurbel concludes that "An important question is would reduction of stressful memories and of stress exposure in everyday life help diminish the risk of getting high blood pressure or metabolic syndrome in the years to come."........

Posted by: Daniel      Read more         Source


October 14, 2008, 7:54 PM CT

How brain sees what you do not see

How brain sees what you do not see
Blindsight is a phenomenon in which patients with damage in the primary visual cortex of the brain can tell where an object is eventhough they claim they cannot see it. A research team led by Prof. Tadashi Isa and Dr. Masatoshi Yoshida of the National Institute for Physiological Sciences, Japan, provides compelling evidence that blindsight occurs because visual information is conveyed bypassing the primary visual cortex. Japan Science and Technology Agency supported this study. The team reports their finding in the Journal of Neuroscience on Oct 15, 2008.

The scientists recorded eye movements of Japanese monkeys that had damage in one side of the primary visual cortex. Training with an eye movement task for 2-3 months enabled the monkeys to move their eyes to the correct direction where an object was even in the affected side of their visual fields. Brain became able to feel where an object was without 'seeing' it. After the training, their eye movements looked almost normal; they discriminated five different directions even in the affected visual field. To investigate how eyes move, the monkeys' eye movements to targets in their affected visual field were compared with those to dark targets in their normal visual field. Both were 'equally difficult to see'. By this trick, the scientists found two differences from the normal: 1) the trajectory of their eye movements was straight and 2) the response time of their eye movement was short. These differences were believed to be due to the damage of eye movement control and decision making, not purely on that of vision. Therefore, the scientists concluded that the monkeys' eye movements after damage in the primary visual cortex were mediated by a qualitatively different vision which is supported by alternative brain circuits bypassing the primary visual cortex.........

Posted by: Daniel      Read more         Source


October 9, 2008, 10:27 PM CT

Communication Between Neurons And Muscle Cells

Communication Between Neurons And Muscle Cells
You can't raise a finger without your brain directing muscle cells, and researchers have figured out another reason that commonly works so well.

A neuron sends a message, or neurotransmitter, to the muscle cell to tell it what to do. To get the message, the receiving cell must have a receptor. Oddly, the unstable protein rapsyn is responsible for anchoring the receptor so it's properly positioned to catch the message.

Medical College of Georgia researchers have found what keeps rapsyn in proper conformation.

It is a heat shock protein, one of a large family of molecular chaperones that make sure proteins get where they are needed and do what they should, says Dr. Lin Mei, chief of developmental neurobiology at MCG and Georgia Research Alliance Eminent Scholar in Neuroscience.

Hsp90ß helps stabilize rapysn so receptors can get and stay where needed, as per research reported in the Oct. 9 issue of Neuron. Dr. Mei suspects that other hsp siblings have a similar caretaker role in neuron-to-neuron communication in the brain.

Researchers knew rapsyn's role in getting neuromuscular receptors to aggregate and stay where needed, but they didn't know what stabilized it. "It makes you wonder how to control this naughty boy which is very important," says Dr. Mei, the study's corresponding author.........

Posted by: Daniel      Read more         Source



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Did you know?
The drug Ativan is better than Valium or Dilantin for controlling severe epileptic seizures, according to a new review of studies.Ativan, or lorazepam, and Valium, or diazepam, are both benzodiazepines, the currently preferred class of drugs for treating severe epileptic seizures. Dilantin, or phenytoin, is an anticonvulsant long used for the treatment of epileptic seizures.

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