January 6, 2009, 9:04 PM CT

Seeing brain aging before symptoms appear

UCLA researchers have used innovative brain-scan technology developed at UCLA, along with patient-specific information on Alzheimer's disease risk, to help diagnose brain aging, often before symptoms appear. Reported in the recent issue of Archives of General Psychiatry, their study may offer a more accurate method for tracking brain aging.

Scientists used positron emission tomography (PET), which allows "a window into the brain" of living people and specifically reveals plaques and tangles, the hallmarks of neurodegeneration. The PET scans were complemented by information on patients' age and congnitive status and a genetic profile.

"Combining key patient information with a brain scan may give us better predictive power in targeting those who appears to benefit from early interventions, as well as help test how well therapys are working," said study author Dr. Gary Small, who holds UCLA's Parlow-Solomon Chair on Aging and is a professor at the Semel Institute for Neuroscience and Human Behavior at UCLA.

Researchers took PET brain scans of 76 non-demented volunteers after they had been intravenously injected with a new chemical marker called FDDNP, which binds to plaque and tangle deposits in the brain. Scientists were then able to pinpoint where these abnormal protein deposits were accumulating......... Posted by: Daniel      Read more         Source

January 2, 2009, 10:43 AM CT

Smoking and family history of stroke

A newly released study shows that people who are smokers and have a family history of brain aneurysm appear to be significantly more likely to suffer a stroke from a brain aneurysm themselves. The research is reported in the December 31, 2008, online issue of Neurology, the medical journal of the American Academy of Neurology and will appear in the January 6, 2009, print issue of Neurology

The type of stroke, called subarachnoid hemorrhage, is one of the bleeding types of stroke and is deadly in about 35 to 40 percent of people.

In the study, researchers looked at 339 people who suffered a stroke from a brain aneurysm and 1,016 people who had not had a stroke due to an aneurysm. Current smokers made up half of the group that had a stroke. The other half had never smoked or had smoked in the past.

The research found people who smoked and had a family history of stroke were more than six times more likely to suffer a stroke than those who did not smoke and did not have a family history of stroke or brain aneurysm. The study also observed that people with a family history of stroke could cut their risk by more than half by quitting smoking. The results were the same regardless of high blood pressure, diabetes, alcohol use, body mass index and education level......... Posted by: Daniel      Read more         Source

December 28, 2008, 11:21 PM CT

Use your unconscious brain to make the best bets

Scientists at the University of Rochester have shown that the human brainonce believed to be a seriously flawed decision makeris actually hard-wired to allow us to make the best decisions possible with the information we are given. The findings appear in today's issue of the journal Neuron

Neuroresearchers Daniel Kahneman and Amos Tversky received a 2002 Nobel Prize for their 1979 research that argued humans rarely make rational decisions. Since then, this has become conventional wisdom among cognition researchers.

Contrary to Kahnneman and Tversky's research, Alex Pouget, associate professor of brain and cognitive sciences at the University of Rochester, has shown that people do indeed make optimal decisionsbut only when their unconscious brain makes the choice.

"A lot of the early work in this field was on conscious decision making, but most of the decisions you make aren't based on conscious reasoning," says Pouget. "You don't consciously decide to stop at a red light or steer around an obstacle in the road. Once we started looking at the decisions our brains make without our knowledge, we observed that they almost always reach the right decision, given the information they had to work with".

Pouget says that Kahneman's approach was to tell a subject that there was a certain percent chance that one of two choices in a test was "right." This meant a person had to consciously compute the percentages to get a right answersomething few people could do accurately......... Posted by: JoAnn      Read more         Source

December 28, 2008, 11:15 PM CT

What triggers Alzheimer's disease?

A slow, chronic starvation of the brain as we age may be a main triggers of a biochemical process that causes some forms of Alzheimer's disease.

A newly released study from Northwestern University's Feinberg School of Medicine has found when the brain doesn't get enough sugar glucose -- as might occur when cardiovascular disease restricts blood flow in arteries to the brain -- a process is launched that ultimately produces the sticky clumps of protein that appear to be a cause of Alzheimer's.

Robert Vassar, main author, discovered a key brain protein is altered when the brain has a deficient supply of energy. The altered protein, called elF2alpha, increases the production of an enzyme that, in turn, flips a switch to produce the sticky protein clumps. Vassar worked with human and mice brains in his research.

The study is reported in the December 26 issue of the journal Neuron

"This finding is significant because it suggests that improving blood flow to the brain might be an effective therapeutic approach to prevent or treat Alzheimer's," said Vassar, a professor of cell and molecular biology at the Feinberg School.

A simple preventive strategy people can follow to improve blood flow to the brain is getting exercise, reducing cholesterol and managing hypertension......... Posted by: Daniel      Read more         Source

December 22, 2008, 5:33 AM CT

Role of cardiovascular proteins in Alzheimer's

Scientists have observed that two proteins which work in tandem in the brain's blood vessels present a double whammy in Alzheimer's disease. Not only do the proteins lessen blood flow in the brain, but they also reduce the rate at which the brain is able to remove amyloid beta, the protein that builds up in toxic quantities in the brains of patients with the disease.

The work, described in a paper published online Dec. 21 in the journal Nature Cell Biology, provides hard evidence directly linking two processes believed to be at play in Alzheimer's disease: reduction in blood flow and the buildup of toxic amyloid beta. The research makes the interaction between the two proteins a seductive target for scientists seeking to address both issues.

Researchers were surprised at the finding, which puts two proteins known for their role in the cardiovascular system front and center in the development of Alzheimer's disease.

"This is quite unexpected," said Berislav Zlokovic, M.D., Ph.D., a neuroscientist and a senior author of the study. "Conversely, both of these processes are mediated by the smooth muscle cells along blood vessel walls, and we know that those are seriously compromised in patients with Alzheimer's disease, so perhaps we shouldn't be completely surprised"......... Posted by: Daniel      Read more         Source

December 16, 2008, 8:17 PM CT

Girls have superior sense of taste to boys

Girls have a better sense of taste than boys. Every third child of school age prefers soft drinks which are not sweet. Children and young people love fish and do not think of themselves as being fussy eaters. Boys have a sweeter tooth than girls. Teenagers taste differently. And finally, schoolchildren in northern Denmark have the best taste buds.

The findings of the world's largest study so far on the ability of children and young people to taste and what they like have now been published. The study was conducted jointly by Danish Science Communication, food researchers from The Faculty of Life Sciences (LIFE) at University of Copenhagen and 8,900 Danish schoolchildren.

In September, 8,900 schoolchildren from all over Denmark took part in a large-scale experiment conducted by Danish Science Communication and The Faculty of Life Sciences (LIFE) at University of Copenhagen. It is the first time that such a large-scale study has been done on the sense of taste of children and young people and what they like to eat.

Danish schoolchildren help scientists

One of the reasons why it was possible to include so a number of children and young people in the study was that the experiment itself was conducted in quite an unorthodox way: It was planned as a 'mass experiment' in conjunction with this year' s natural science festival at Danish primary and secondary schools......... Posted by: Janet      Read more         Source

December 11, 2008, 10:26 PM CT

A fading sense of smell may signal Parkinson's disease

A number of individuals with Parkinson's disease are able to recall losing their sense of smell well before the onset of more usually recognized symptoms such as tremors, impaired dexterity, speech problems, memory loss and decreased cognitive ability. To determine if a fading sense of smell may signal Parkinson's, scientists at Northwestern Memorial Hospital and Northwestern University's Feinberg School of Medicine are participating in a national study to examine the correlation and ascertain whether smell loss presents a tool for early detection of the disease and an opportunity to delay or ultimately prevent more troublesome symptoms.

Nearly one million people in the United States are affected by Parkinson's disease, which stems from premature aging of dopamine-producing cells in the brain, and the number is likely to grow as the population ages. By the time Parkinson's disease is detected, most individuals have already experienced a 60 to 70 percent loss of dopamine-producing cells in the brain.

"Very little is known about the early stages of this disease," says Tanya Simuni, MD, director of Northwestern's Parkinson's Disease and Movement Disorders Center and Associate Professor of Neurology at Northwestern University's Feinberg School of Medicine. "By utilizing smell testing in conjunction with other tests, we hope to develop a system that identifies the presence of Parkinson's before it develops into problematic symptoms."........ Posted by: Daniel      Read more         Source

December 11, 2008, 5:28 AM CT

If MRI shows signs of MS, will the disease develop?

With more and more people having brain MRIs for various reasons, doctors are finding people whose scans show signs of multiple sclerosis (MS) even though they have no symptoms of the disease. A new study reported in the December 10, 2008, online issue of Neurology, the medical journal of the American Academy of Neurology, observed that a third of these people developed MS within an average of about five years.

The study involved 44 people who had brain scans for various reasons, such as migraine headaches or head trauma, that showed abnormalities similar to those that occur in MS. The scientists confirmed that the abnormalities were the same as in MS and ruled out other possible causes. Then the scientists monitored the participants to determine whether they developed the disease.

Within an average of 5.4 years, 30 percent of the participants had developed MS symptoms. The brain scans of an additional 29 percent of the people showed further abnormalities, but they continued to have no symptoms of the disease.

"More studies are needed to fully understand the risk of developing MS for people with these brain abnormalities, but it appears that this condition may be a precursor to MS," said study author Darin T. Okuda, MD, of the University of California, San Francisco, the UCSF Multiple Sclerosis Center and a member of the American Academy of Neurology......... Posted by: Daniel      Read more         Source

December 11, 2008, 5:09 AM CT

Strategic video game improves critical cognitive skills

A desire to rule the world may be a good thing if you're over 60 and worried about losing your mental faculties. A new study observed that adults in their 60s and 70s can improve many cognitive functions by playing a strategic video game that rewards nation-building and territorial expansion.

This is the first such study of elderly adults, and it is the first to find such pronounced effects on cognitive skills not directly correlation to the skills learned in the video game, said University of Illinois psychology professor Arthur Kramer, an author on the study.

The research appears this month in the journal Psychology & Aging

Decades of laboratory studies designed to improve specific cognitive skills, such as short-term memory, have found again and again that trainees improve almost exclusively on the tasks they perform in the lab and only under laboratory conditions, Kramer said.

"When you train somebody on a task they tend to improve in that task, whatever it is, but it commonly doesn't transfer much beyond that skill or beyond the particular situation in which they learned it," he said. "And there are virtually no studies that examine whether there's any transfer outside the lab to things people care about".

Kramer and colleagues wanted to know whether a more integrated training approach could go beyond the training environment to enhance the cognitive skills used in every day life. Specifically, the scientists wondered whether interactive video games might benefit those cognitive functions that decline most with age......... Posted by: Daniel      Read more         Source

December 6, 2008, 3:53 PM CT

Maintaining the brain's wiring in aging and disease

Scientists at the Babraham Institute near Cambridge, supported by the Alzheimer's Research Trust and the Biotechnology and Biological Sciences Research Council (BBSRC), have discovered that the brain's circuitry survives longer than previously thought in diseases of ageing such as Alzheimer's disease. The findings were published recently in the journal Brain

Alzheimer's disease causes nerve cells in the brain to die, resulting in problems with memory, speech and understanding. Little is known about how the nerve cells die, but this new research has revealed how they first lose the ability to communicate with each other, before deteriorating further.

"We've all experienced how useless a computer is without broadband. The same is true for a nerve cell (neuron) in the brain whose wiring (axons and dendrites) has been lost or damaged," explained Dr Michael Coleman the project's lead researcher. "Once the routes of communication are permanently down, the neuron will never again contribute to learning and memory, because these 'wires' do not re-grow in the human brain." .

But axons and dendrites are much more than inert fibre-optic wires. They are homes to the world's smallest transport tracks. Every one of our hundred billion nerve cells continuously shuttles hundreds of proteins and intracellular packages out along its axons and dendrites, and back again, during every minute of every day. Without this process, the wires cannot be maintained and the nervous system will cease to function within a few hours......... Posted by: Daniel      Read more         Source

December 3, 2008, 5:28 AM CT

Surgery to treat medication-resistant epilepsy

Persons with temporal lobe epilepsy who do not respond to medicine could receive a substantial gain in life expectancy and quality of life by undergoing surgery of the temporal lobe part of the brain, as per an analysis published in the December 3 issue of JAMA.

Despite currently available anti-epileptic drugs, 20 percent to 40 percent of all patients with epilepsy do not respond to medical management. Temporal lobe epilepsy is the most common form of epilepsy and the most likely to be medically non-responsive, and these patients are at increased risk of premature death, as per background information in the article. An alternative form of therapy is temporal lobe resection (procedure in which brain tissue in the temporal lobe is cut away). Patients becoming seizure free after anterior (toward the front) temporal lobe resection have reduced death rates relative to patients continuing to have seizures.

"Studies have reported the effectiveness of temporal lobe resection since the 1950s, yet a minority of patients are being referred to surgery and those only after an average of 20 years of illness. For adolescents and young adults, this delay may be especially significant during a critical period in their psychosocial development," the authors write.

Hyunmi Choi, M.D., M.S., of the Columbia University Medical Center, New York, and his colleagues conducted an analysis using a simulation model to estimate the effect of anterior temporal lobe resection vs. continued medical management on life expectancy and quality-adjusted life expectancy among patients with medication-resistant temporal lobe epilepsy. The model incorporated possible surgical complications and seizure status and was populated with health-related quality-of-life data obtained directly from patients and data from the medical literature......... Posted by: Daniel      Read more         Source

December 1, 2008, 5:55 PM CT

Exercise helps prevent age-related brain changes

Elderly adults who exercise regularly show increased cerebral blood flow and a greater number of small blood vessels in the brain, as per findings presented today at the annual meeting of the Radiological Society of North America (RSNA).

The study, conducted at the University of North Carolina (UNC) Chapel Hill, is the first to compare brain scans of elderly adults who exercise to brain scans of those who do not.

"Our results show that exercise may reduce age-related changes in brain vasculature and blood flow," said presenter Feraz Rahman, M.S., currently a medical student at Jefferson Medical College in Philadelphia. "Other studies have shown that exercise prevents cognitive decline in the elderly. The blood vessel and flow differences may be one reason".

The scientists recruited 12 healthy adults, age 60 to 76. Six of the adults had participated in aerobic exercise for three or more hours per week over the last 10 years, and six exercised less than one hour per week. All of the volunteers underwent MRI to determine cerebral blood flow and MR angiography to depict blood vessels in the brain.

Using a novel method of three-dimensional (3-D) computer reconstruction developed in their lab, the scientists were able to make 3-D models of the blood vessels and examine them for shape and size. They then compared the blood vessel characteristics and how they correlation to blood flow in both the active and inactive groups......... Posted by: JoAnn      Read more         Source

November 25, 2008, 10:34 PM CT

Pain is in the eyes of the beholder

By manipulating the appearance of a chronically achy hand, scientists have found they could increase or decrease the pain and swelling in patients moving their symptomatic limbs. The findingspublished in the November 25th issue of Current Biology, a Cell Press publicationreveal a profound top-down effect of body image on body tissues, as per the researchers.

"The brain is capable of a number of wonderful things based on its perception of how the body is doing and the risks to which the body seems to be exposed," said G. Lorimer Moseley, who is now at the Prince of Wales Medical Research Institute in Australia. (The work was done at the University of Oxford.).

In the study, the scientists asked ten right-handed patients with chronic pain and dysfunction in one arm to watch their own arm while they performed a standardized set of ten hand movements. The participants repeated the movements under four conditions: with no visual manipulation, while looking through binoculars with no magnification, while looking through binoculars that doubled the apparent size of their arm, and while looking through inverted binoculars that reduced the apparent size of their arm.

While the patients' pain was always worse after movement than it was before, the extent to which the pain worsened depended on what people saw. Specifically, the pain increased more when participants viewed a magnified image of their arm during the movements, andperhaps more surprisinglythe pain became less when their arm was seen through inverted binoculars that minimized its size......... Posted by: Daniel      Read more         Source

November 25, 2008, 9:50 PM CT

Do you know you're having a stroke?

A Mayo Clinic study shows a majority of stroke patients don't think they're having a stroke -- and as a result -- delay seeking therapy until their condition worsens. The findings are reported in the current issue of Emergency Medicine Journal at http://emj.bmj.com/.

Scientists studied 400 patients who were diagnosed at Mayo Clinic's emergency department with either acute ischemic stroke or a transient ischemic attack (TIA), a temporary interruption of blood flow to part of the brain.

Less than half of the patients -- 42 percent -- thought they were having a stroke. In fact, most in the study did not go to the emergency room when symptoms appeared. The median time from onset of symptoms to arrival at the hospital was over three and a half hours. Most said they thought the symptoms would simply go away. The delay in seeking medical help was the same among men and women.

When asked how they knew about stroke symptoms, nearly one-fifth said they thought a stroke always came on gradually. Just over half (51.9 percent) said they thought that seeking medical care immediately was important.



Significance of the findings

"Time is crucial in treating stroke," says Latha Stead, M.D., emergency medicine specialist and lead author of the study. "Each individual's medical background differs and affects recovery, but in general the sooner a patient experiencing a stroke reaches emergency care, the more likely the stroke can be limited and the condition managed to prevent further damage and improve recovery." The scientists say their findings clearly indicate that better public understanding of stroke symptoms will lead to a faster response and better outcomes......... Posted by: Daniel      Read more         Source

November 19, 2008, 8:41 PM CT

How brain makes sense of natural scenes

Computational neuroresearchers at Carnegie Mellon University have developed a computational model that provides insight into the function of the brain's visual cortex and the information processing that enables people to perceive contours and surfaces, and understand what they see in the world around them.

A type of visual neuron known as simple cells can detect lines, or edges, but the computation they perform is insufficient to make sense of natural scenes, said Michael S. Lewicki, associate professor in Carnegie Mellon's Computer Science Department and the Center for the Neural Basis of Cognition. Edges often are obscured by variations in the foreground and background surfaces within the scene, he said, so more sophisticated processing is necessary to understand the complete picture. But little is known about how the visual system accomplishes this feat.

In a paper published online by the journal Nature, Lewicki and his graduate student, Yan Karklin, outline their computational model of this visual processing. The model employs an algorithm that analyzes the myriad patterns that compose natural scenes and statistically characterizes those patterns to determine which patterns are most likely linked to each other.

The bark of a tree, for instance, is composed of a multitude of different local image patterns, but the computational model can determine that all these local images represent bark and are all part of the same tree, as well as determining that those same patches are not part of a bush in the foreground or the hill behind it......... Posted by: Daniel      Read more         Source

November 18, 2008, 5:15 AM CT

Gene associated with epilepsy

A University of Iowa-led international research team has found a new gene linked to the brain disorder epilepsy. While the PRICKLE1 gene mutation was specific to a rare form of epilepsy, the study results could help lead to new ideas for overall epilepsy therapy.

The findings, which involved nearly two dozen institutions from six different countries, appear in the Nov. 7 issue of the American Journal of Human Genetics

In epilepsy, nerve cells in the brain signal abnormally and cause repeated seizures that can include strange sensations, severe muscle spasms and loss of consciousness. The seizures may not have lasting effects but can affect activities, such as limiting a person's ability to drive. Most seizures do not cause brain damage but some types of epilepsy lead to physical disabilities and cognitive problems. Medications can control symptoms, but there is no cure.

"The study results were surprising not only because the PRICKLE1 gene had never been linked to epilepsy but also because the gene was not linked to any other human disease," said the study's lead author Alex Bassuk, M.D., Ph.D., assistant professor of pediatrics at the University of Iowa Carver College of Medicine and a pediatric neurologist with University of Iowa Children's Hospital......... Posted by: Daniel      Read more         Source

November 18, 2008, 5:13 AM CT

Exercise increases brain growth factor

A new study confirms that exercise can reverse the age-related decline in the production of neural stem cells in the hippocampus of the mouse brain, and suggests that this happens because exercise restores a brain chemical which promotes the production and maturation of new stem cells.

Neural stem cells and progenitor cells differentiate into a variety of mature nerve cells which have different functions, a process called neurogenesis. There is evidence that when fewer new stem or progenitor cells are produced in the hippocampus, it can result in impairment of the learning and memory functions. The hippocampus plays an important role in memory and learning.

The study, "Exercise enhances the proliferation of neural stem cells and neurite growth and survival of neuronal progenitor cells in dentate gyrus of middle-aged mice," was carried out by Chih-Wei Wu, Ya-Ting Chang, Lung Yu, Hsiun-ing Chen, Chauying J. Jen, Shih-Ying Wu, Chen-Peng Lo, Yu-Min Kuo, all of the National Cheng Kung University Medical College in Taiwan. The study appears in the recent issue of the Journal of Applied Physiology, published by The American Physiological Society.

Rise in corticosterone or fall in nerve growth factor?

The scientists built on earlier studies that observed that the production of stem cells in the area of the hippocampus known as the dentate gyrus drops off dramatically by the time mice are middle age and that exercise can slow that trend. In the current study, the scientists wanted to track these changes in mice over time, and find out why they happen......... Posted by: Daniel      Read more         Source

November 14, 2008, 9:42 PM CT

When You Look at a Face, You Look Nose First

While general wisdom says that you look at the eyes first in order to recognize a face, UC San Diego computer researchers now report that you look at the nose first.

The nose may be the where the information about the face is balanced in all directions, or the optimal viewing position for face recognition, the scientists from UC San Diego's Jacobs School of Engineering propose in a paper recently reported in the journal Psychological Science.

The scientists showed that people first look just to the left of the center of the nose and then to the center of the nose when trying to determine if a face is one they have seen recently. These two visual "fixations" near the center of the nose are all you need in order to determine if a face is one that you have seen just a few minutes before. Looking at a third spot on the face does not improve face recognition, the cognitive researchers found.

Understanding how the human brain recognizes faces may help cognitive researchers create more realistic models of the brain-models that could be used as tools to train or otherwise assist people with brain lesions or cognitive challenges, explained Janet Hsiao, the first author on the Psychological Science paper and a postdoctoral researcher in the computer science department at UC San Diego......... Posted by: Daniel      Read more         Source

November 14, 2008, 9:02 PM CT

How the brain takes care of things

Thanks to our ability to learn and to remember, we can perform tasks that other living things can not even dream of. However, we are only just beginning to get the gist of what really goes on in the brain when it learns or forgets something. What we do know is that changes in the contacts between nerve cells play an important role. But can these structural changes account for that well-known phenomenon that it is much easier to re-learn something that was forgotten than to learn something completely new? Researchers at the Max Planck Institute of Neurobiology have been able to show that new cell contacts established during a learning process stay put, even when they are no longer required. The reactivation of this temporarily inactivated "stock of contacts" enables a faster learning of things forgotten. (Nature, November 12, 2008).

While an insect still flings itself against the window-pane after dozens of unsuccessful attempts to gain its freedom, our brain is able to learn very complex associations and sequences of movement. This not only helps us to avoid accidents like walking into glass doors, but also enables us to acquire such diverse skills as riding a bicycle, skiing, speaking different languages or playing an instrument. Eventhough a young brain learns more easily, we retain our ability to learn up to an advanced age. For a long time, researchers have been trying to ascertain exactly what happens in the brain while we learn or forget......... Posted by: Daniel      Read more         Source

November 13, 2008, 10:28 PM CT

Protecting neurons could halt Alzheimer's

Scientists at Southern Methodist University (SMU) and The University of Texas at Dallas (UTD) have identified a group of chemical compounds that slow the degeneration of neurons, a condition behind old-age diseases like Alzheimer's, Parkinson's and amyotrophic lateral sclerosis (ALS).

Their findings are featured in the November 2008 edition of Experimental Biology and Medicine SMU Chemistry Professor Edward R. Biehl and UTD Biology Professor Santosh D'Mello teamed to test 45 chemical compounds. Four were found to be the most potent protectors of neurons, the cells that are core components of the human brain, spinal cord and peripheral nerves.

The most common cause of neurodegenerative disease is aging. Current medications only alleviate the symptoms but do not affect the underlying cause degeneration of neurons. The identification of compounds that inhibit neuronal death is of urgent and critical importance.

The synthesized chemicals identified by Biehl and D'Mello, called "3-substituted indolin-2-one compounds" are derivatives of another compound called GW5074 which was shown to prevent neurodegeneration in a past report published by the D'Mello lab. While effective at protecting neurons from decay or death, GW5074 is toxic to cells at slightly elevated doses, which makes it unsuitable for clinical testing in patients......... Posted by: Daniel      Read more         Source

November 12, 2008, 10:37 PM CT

Hormone shows promise in reversing Alzheimer's disease

Saint Louis University scientists have identified a novel way of getting a potential therapy for Alzheimer's disease and stroke into the brain where it can do its work.

"We found a unique approach for delivering drugs to the brain," says William A. Banks, M.D., professor of geriatrics and pharmacological and physiological science at Saint Louis University. "We're turning off the guardian that's keeping the drugs out of the brain".

The brain is protected by the blood-brain barrier (BBB), a gate-keeping system of cells that lets in nutrients and keeps out foreign substances. The blood-brain barrier passes no judgment on which foreign substances are trying to get into the brain to treat diseases and which are trying to do harm, so it blocks them without discrimination.

"The problem in treating a lot of diseases of the central nervous system such as Alzheimer's disease, HIV and stroke is that we can't get drugs past the blood-brain barrier and into the brain," says Banks, who also is a staff doctor at Veterans Affairs Medical Center in St. Louis.

"Our new research shows a way of getting a promising therapy for these types of devastating diseases to where they need to be to work".

The treatment known as PACAP27 -- is a hormone produced by the body that is a general neuro-protectant. PACAP stands for pituitary adenylate cyclase-activating polypeptide. "It is a general protector of the brain against a number of types of insult and injury," Banks says......... Posted by: Daniel      Read more         Source

November 12, 2008, 10:18 PM CT

In the war against diseases, nerve cells need their armor

In a new study, scientists at the Montreal Neurological Institute (MNI), McGill University, and the Universit de Montral have discovered an essential mechanism for the maintenance of the normal structure of myelin, the protective covering that insulates and supports nerve cells (neurons). Up until now, very little was known about myelin maintenance. This new information provides vital insight into diseases such as Multiple Sclerosis (MS) and other progressive demyelinating diseases in which myelin is destroyed, causing irreversible damage and disrupting the nerve cells' ability to transmit messages. The research, published recently in the Journal of Neuroscience, is the first to identify a role for the protein netrin-1, previously characterized only in the developing nervous system, with this critical function in the adult nervous system. This research was funded by the MS Society of Canada and the Canadian Institutes of Health Research.

Netrin-1, a protein deriving its name from the ancient Indian language, Sanskrit, word for 'one who guides,' is known to guide and direct nerve cell axons to their targets. In the molecular biological studies conducted by the team, they observed that blocking the function of netrin-1 and one of its receptors in adult neural tissue causes the disruption of myelin. "We've known for just over 10 years that netrin is essential for normal development of the nervous system, and we also knew that netrin was present in the adult brain, but we didn't know why. It is fascinating that netrin-1 has such a vital role in maintaining the structure of myelin in the adult nervous system," says Dr. Tim Kennedy, a neuroscientist at the MNI and the senior investigator of this study, "continuing to pursue the implications of that are incredibly exciting." "Our mission is to find a cure as quickly as possible and enhance quality of life," says Karen Lee, assistant vice-president of research programs for the MS Society of Canada. "We are pleased to be involved in funding work that supports our mission and feel that this research takes us closer to understanding the players and processes that could aid in remyelination."........ Posted by: Daniel      Read more         Source

November 11, 2008, 12:09 AM CT

Protein can nurture or devastate brain cells

Scientists at UT Southwestern Medical Center have uncovered new insights into the "Dr. Jekyll and Mr. Hyde" nature of a protein that stimulates stem-cell maturation in the brain but, paradoxically, can also lead to nerve-cell damage.

In two separate studies in mice scheduled to appear online this week and in an upcoming issue of the Proceedings of the National Academy of Sciences, UT Southwestern research teams studied the protein Cdk5 and discovered both helpful and detrimental mechanisms it elicits in nerve cells.

Dr. Amelia Eisch, assistant professor of psychiatry at UT Southwestern, and her colleagues uncovered a beneficial mechanism of the helpful "Dr. Jekyll" side of the Cdk5 protein, which is also thought to kill brain cells and contribute to neurodegenerative diseases such as Alzheimer's. In the current study, Dr. Eisch observed that Cdk5, together with its activating partner molecule p35, helps immature nerve cells become fully functional.

In a separate study, Dr. James Bibb, associate professor of psychiatry at.

UT Southwestern, found yet another harmful action of the Cdk5 protein. It can stunt learning and reduce motor control.

Cdk5 is a kinase, which means its job is to interact with all sorts of other proteins inside cells and modify them through a process called protein phosphorylation. Whether Cdk5 nurtures or devastates depends on the state of its partner and the proteins it modifies......... Posted by: Daniel      Read more         Source

October 27, 2008, 10:30 PM CT

Brain stimulation improves dexterity

Applying electrical stimulation to the scalp and the underlying motor regions of the brain could make you more skilled at delicate tasks. Research published recently in the open access journal BMC Neuroscience shows that a non-invasive brain-stimulation technique, transcranial direct current stimulation (tDCS), is able to improve the use of a person's non-dominant hand.

Drs. Gottfried Schlaug and Bradley Vines from Beth Israel Deaconess Medical Center and Harvard Medical School, tested the effects of using tDCS over one side or both sides of the brain on sixteen healthy, right-handed volunteers, as well as testing the effect of simply pretending to carry out the procedure. The volunteers were not aware of which of the three procedures they were receiving. The test involved using the fingers of the left hand to key in a series of numbers displayed on a computer screen.

The results were striking; stimulating the brain over both the right and left motor regions ('dual hemisphere' tDCS) resulted in a 24% improvement in the subjects' scores. This was significantly better than stimulating the brain only over one motor region or using the sham therapy (16% and 12% improvements, respectively).

tDCS involves attaching electrodes to the scalp and passing a weak direct current through the scalp and skull to alter the excitability of the underlying brain tissue. The therapy has two principal modes depending on the direction in which the current runs between the two electrodes. Brain tissue that underlies the positive electrode (anode) becomes more excitable and the reverse is true for brain tissue that underlies the negative electrode (cathode). No relevant negative side effects have been reported with this type of non-invasive brain stimulation. It is not to be confused with electroconvulsive treatment, which uses currents around a thousand times higher......... Posted by: Daniel      Read more         Source