MedicineWorld.Org
Your gateway to the world of medicine
Home
News
Cancer News
About Us
Cancer
Health Professionals
Patients and public
Contact Us
Disclaimer

Medicineworld.org: Archives of neurology news blog


Go Back to the main neurology news blog

Subscribe To Health Blog RSS Feed  RSS content feed What is RSS feed?

Archives Of Neurology News Blog From Medicineworld.Org


October 8, 2008, 9:39 PM CT

Circadian clock may be critical for remembering

Circadian clock may be critical for remembering
The circadian rhythm that quietly pulses inside us all, guiding our daily cycle from sleep to wakefulness and back to sleep again, may be doing much more than just that simple metronomic task, as per Stanford researchers.

Working with Siberian hamsters, biologist Norman Ruby has shown that having a functioning circadian system is critical to the hamsters' ability to remember what they have learned. Without it, he said, "They can't remember anything".

Though not known for their academic prowess, Siberian hamsters nonetheless normally develop what amounts to street smarts about their environment, as do all animals. But hamsters whose circadian system was disabled by a new technique Ruby and colleagues developed consistently failed to demonstrate the same evidence of remembering their environment as hamsters with normally functioning circadian systems.

Until now, it has never been shown that the circadian system is crucial to learning and memory. The finding has implications for diseases that include problems with learning or memory deficits, such as Down syndrome or Alzheimer's disease. The work is described in a paper published Oct. 1 online in the early edition of the Proceedings of the National Academy of Sciences Ruby is lead author on the paper. Siberian hamsters, also known as dwarf hamsters, are about the size of a mouse.........

Posted by: Daniel      Read more         Source


October 6, 2008, 10:37 PM CT

African-Americans may be at higher risk of stroke

African-Americans may be at higher risk of stroke
Cerebral microbleeds, which are small bleeds within the brain, appear to be more common in African-Americans than in Caucasians, increasing the likelihood of having a stroke, as per a research studyreported in the October 7, 2008, issue of Neurology, the medical journal of the American Academy of Neurology. These types of brain lesions can be an important indicator for stroke.

For the study, 87 people from the Washington, DC, area who had suffered a certain type of stroke, called an intracerebral hemorrhage, underwent brain scans. This kind of stroke involves bleeding in the brain and makes up 10 to 15 percent of all strokes. Scientists also determined the group's risk factors for stroke such as age, high blood pressure and alcohol use. Forty-two of the people were African-American while 45 were Caucasian.

The study observed that African-Americans had 32 percent more microbleeds than Caucasians. African-Americans were also more likely to have these types of lesions in several different areas of the brain. While African-Americans had more lesions in the lower and middle parts of the brain, Caucasians had them most frequently near the surface of the brain.

"Finding racial differences that could be linked with a higher prevalence for these brain lesions may lead to new methods for testing and treating people to prevent stroke," said study author Chelsea Kidwell, MD, with Georgetown University Medical Center in Washington, DC, and member of the American Academy of Neurology.........

Posted by: Daniel      Read more         Source


October 6, 2008, 10:32 PM CT

Occasional memory loss tied to lower brain volume

Occasional memory loss tied to lower brain volume
People who occasionally forget an appointment or a friend's name may have a loss of brain volume, even though they don't have memory deficits on regular tests of memory or dementia, as per a research studyreported in the October 7, 2008, issue of Neurology, the medical journal of the American Academy of Neurology.

The study involved 500 people age 50 to 85 with no dementia who lived in the Netherlands. Participants were asked about occasional memory problems such as having trouble thinking of the right word or forgetting things that happened in the last day or two, or thinking problems such as having trouble concentrating or thinking more slowly than they used to.

Participant's brains were scanned to measure the size of the hippocampus, an area of the brain important for memory and one of the first areas damaged by Alzheimer's disease.

Of the 500 people, 453 reported that they had occasional memory or thinking problems, which are also called subjective memory problems, because they would not show up on regular tests of memory and thinking skills.

The study observed that in people with occasional subjective memory problems, the hippocampus was smaller than in people who had no memory problems. On average, the hippocampus had a volume of 6.7 milliliters in those with occasional subjective memory problems, in comparison to 7.1 milliliters in people with no memory problems.........

Posted by: Daniel      Read more         Source


October 2, 2008, 10:35 PM CT

Musicians use both sides of their brains more frequently

Musicians use both sides of their brains more frequently
Supporting what a number of of us who are not musically talented have often felt, new research reveals that trained musicians really do think differently than the rest of us. Vanderbilt University psychology experts have observed that professionally trained musicians more effectively use a creative technique called divergent thinking, and also use both the left and the right sides of their frontal cortex more heavily than the average person.

The research by Crystal Gibson, Bradley Folley and Sohee Park is currently in press at the journal Brain and Cognition

"We were interested in how individuals who are naturally creative look at problems that are best solved by thinking 'out of the box'," Folley said. "We studied musicians because creative thinking is part of their daily experience, and we observed that there were qualitative differences in the types of answers they gave to problems and in their associated brain activity." .

One possible explanation the scientists offer for the musicians' elevated use of both brain hemispheres is that a number of musicians must be able to use both hands independently to play their instruments.

"Musicians may be especially good at efficiently accessing and integrating competing information from both hemispheres," Folley said. "Instrumental musicians often integrate different melodic lines with both hands into a single musical piece, and they have to be very good at simultaneously reading the musical symbols, which are like left-hemisphere-based language, and integrating the written music with their own interpretation, which has been associated with the right hemisphere".........

Posted by: Daniel      Read more         Source


September 28, 2008, 8:42 PM CT

'Hub' of fear memory formation identified in brain cells

'Hub' of fear memory formation identified in brain cells
A protein mandatory for the earliest steps in embryonic development also plays a key role in solidifying fear memories in the brains of adult animals, researchers have revealed. An apparent "hub" for changes in the connections between brain cells, beta-catenin could be a potential target for drugs to enhance or interfere with memory formation.

The results are published online this week and appear in the recent issue of Nature Neuroscience

The protein beta-catenin acts like a Velcro strap, fastening cells' internal skeletons to proteins on their external membranes that connect them with other cells. In species ranging from flies to frogs to mice, it also can transmit early signals that separate an embryo into front and back or top and bottom.

During long-term memory formation, structural changes take place in the synapses the connections between neurons in the brain, says Kerry Ressler, MD, PhD, associate professor of psychiatry and behavioral sciences at Emory University School of Medicine. Ressler is a researcher at Emory University's Yerkes National Primate Research Center, where the research was conducted, and a Howard Hughes Medical Institute investigator.

"We thought beta-catenin could be a hub for the changes that take place in the synapses during memory formation," says Ressler. "But because beta-catenin is so important during development, we couldn't take the standard approach of just knocking it out genetically".........

Posted by: Daniel      Read more         Source


September 24, 2008, 7:04 PM CT

Not a moment to lose in therapy for acute stroke

Not a moment to lose in therapy for acute stroke
In an editorial response to a report in the September 25 issue of the New England Journal (NEJM) on the efficacy of intravenous thrombolysis therapy in the hours after acute ischemic stroke, Patrick Lyden, M.D., professor of neurosciences and director of the UC San Diego Stroke Center, cautions that the study should not be interpreted to mean that such treatment can be withheld for hours or even minutes.

"The risk of withholding such therapy from patients with acute stroke greatly exceeds the risk of giving it," said Lyden. "The potential for reversing the disabling side effects of stroke declines with every passing minute".

The study, ("Thrombolysis with Alteplase 3 to 4.5 Hours after Acute Ischemic Stroke") by Werner Hacke, M.D. et al, reports the findings from the European Cooperative Acute Stroke Study III (ECASS III).

The design of this study closely mirrored that of the original National Institute of Neurological Disorders and Stroke (NINDS) trial of recombinant tissue plasminogen activator (rt-PA) for acute stroke, a pivotal trial that Lyden helped lead that showed the first proven treatment for stroke. The important exception in the ECASS III trial is that the window of treatment was expanded to a period of three to four and a half hours, in comparison to under three hours in the NINDS trial.........

Posted by: Daniel      Read more         Source


September 24, 2008, 6:21 PM CT

Balancing the brain

Balancing the brain
Neuroresearchers at Children's Hospital Boston have identified the first known "master switch" in brain cells to orchestrate the formation and maintenance of inhibitory synapses, essential for proper brain function. The factor, called Npas4, regulates more than 200 genes that act in various ways to calm down over-excited cells, restoring a balance that is thought to go askew in some neurologic disorders. The findings are reported in the September 24 advance online edition of the journal Nature

Synapses, the connections between brain cells, can be excitatory or inhibitory in nature. At birth, the rapidly developing brain teems with excitatory synapses, which tend to make nerve cells "fire" and stimulate their neighbors. But if the excitation isn't eventually balanced, it can lead to epilepsy, and diseases like autism and schizophrenia have been linked to an imbalance of excitation and inhibition. The creation of inhibitory connections is also necessary to launch critical periods -- windows of rapid learning during early childhood and adolescence, when the brain is very "plastic" and able to rewire itself.

Npas4 is a transcription factor, a switch that activates or represses other genes. The researchers, led by Michael Greenberg, PhD, director of the Neurobiology Program at Children's, demonstrated that the activity of as a number of as 270 genes changes when Npas4 activity is blocked in a cell, and that Npas4 activation is linked to an increased number of inhibitory synapses on the cell's surface.........

Posted by: Daniel      Read more         Source


September 18, 2008, 10:39 PM CT

Breakthrough in spinal injury treatment

Breakthrough in spinal injury treatment
Manipulating embryo-derived stem cells before transplanting them may hold the key to optimizing stem cell technologies for repairing spinal cord injuries in humans. Research published in BioMed Central's open access Journal of Biology, may lead to cell based therapies for victims of paralysis to recover the use of their bodies without the risk of transplant induced pain syndromes.

Dr. Stephen Davies, Associate Professor of Neurosurgery at the University of Colorado Denver School of Medicine, reported that in collaboration with scientists at the University of Rochester, NY his research team has transplanted two types of the major support cells of the brain and spinal cord, cells called astrocytes. These two types of astrocytes, which are both made from the same embryo-derived stem cell-like precursor cell, have remarkably different effects on the spinal repair process.

Using signal molecules known to be involved in the generation of embryonic astrocytes during spinal cord development, the scientists were able to make pure cultures of two different types of astrocytes from the GRP cells.

When Dr. Davies and his team transplanted these two types of astrocytes into the injured spinal cord, they had dramatically different effects. One type of astrocyte called GDAsBMP was remarkably effective at promoting nerve regeneration and recovery of limb motion when transplanted into spinal cord injuries. However, the other type of astrocyte cell generated called GDAsCNTF, not only failed to promote nerve fiber regeneration or functional recovery but also caused neuropathic pain, a severe side effect that was not seen in rats treated with GDAsBMP.........

Posted by: Daniel      Read more         Source


September 15, 2008, 10:08 PM CT

Migraine linked to blood clots in veins

Migraine linked to blood clots in veins
People with migraines may also be more likely to develop blood clots in their veins, as per a research studyreported in the September 16, 2008, issue of Neurology®, the medical journal of the American Academy of Neurology.

In the condition, called venous thrombosis or thromboembolism, blood clots form in a vein, which can limit blood flow and cause swelling and pain. Those clots can then dislodge from the vein and travel to the heart and the lungs, which can be fatal.

For the study, 574 people in Italy age 55 and up were interviewed to determine whether they had a history of migraine or migraine at the time of the evaluation and their medical records were evaluated for cases of venous thrombosis. The arteries in their necks and thighs were scanned with ultrasounds to check for atherosclerosis, or hardening of the arteries.

Of the participants, 111 people had migraine. A total of 21 people with migraine also had one or more instances of venous thrombosis, or 19 percent. In comparison, 35 people without migraine had the condition, or 8 percent.

Scientists do not know why migraine and venous thrombosis are linked. One theory is that the blood of people with migraine may be more prone to clotting.

The study also observed that people with migraine are not more likely to have hardening or narrowing of the arteries, which is contrary to a current theory.........

Posted by: Daniel      Read more         Source


September 10, 2008, 10:11 PM CT

Immaturity of the brain may cause schizophrenia

Immaturity of the brain may cause schizophrenia
The underdevelopment of a specific region in the brain may lead to schizophrenia in individuals. As per research published recently in BioMed Central's open access journal Molecular Brain, dentate gyrus, which is located in the hippocampus in the brain and believed to be responsible for working memory and mood regulation, remained immature in an animal model of schizophrenia.

Professor Tsuyoshi Miyakawa of Fujita Health University, National Institute for Physiological Sciences (NIPS), and Kyoto University led a research team in Japan, with support from the CREST program of Japan Science and Technology Agency (JST). First, the team investigated behaviors by conducting a systematic and well-defined behavioral test battery with alpha-CaMKII mutant mice, an animal model of schizophrenia. These mice showed abnormal behaviors similar to those of schizophrenic patients. Next, the team found the dentate gyrus neurons in hippocampus of the brain of these mice were not matured morphologically and physiologically. By a gene expression analysis, changes of gene expression correlation to the maturation of dentate gyrus neurons were also found in the brains of schizophrenic patients. Taken together, the immaturity of the dentate gyrus may be an underlying cause for schizophrenia.........

Posted by: Daniel      Read more         Source



Older Blog Entries   1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46  

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.

Medicineworld.org: Archives of neurology news blog

Acute bacterial meningitis| Alzheimer's disease| Carpal tunnel syndrome| Cerebral aneurysms| Cerebral palsy| Chronic fatigue syndrome| Cluster headache| Dementia| Epilepsy seizure disorders| Febrile seizures| Guillain barre syndrome| Head injury| Hydrocephalus| Neurology| Insomnia| Low backache| Mental retardation| Migraine headaches| Multiple sclerosis| Myasthenia gravis| Neurological manifestations of aids| Parkinsonism parkinson's disease| Personality disorders| Sleep disorders insomnia| Syncope| Trigeminal neuralgia| Vertigo|

Copyright statement
The contents of this web page are protected. Legal action may follow for reproduction of materials without permission.