Newsline — Thursday, June 26, 2014 8:55
Tangled Path of Alzheimer’s-linked Brain Cells Mapped in Mice
REM Sleep Disturbance Signals Future Neurodegenerative Disease
Wednesday, June 25, 2014 13:00
REM behavior disorder, a sleep disorder, could be a sign of impending neurodegenerative disease, including Parkinson’s and dementia, scientists reported recently. Researchers are not sure why spontaneous and unexplained disturbance in REM sleep should lead to a neurodegenerative disease, but new longitudinal imaging data show a clear correlation between idiopathic REM behavior disorder and dysfunction of the dopamine transporter system involved in a range of vital brain functions. In order to gauge the relationship between the REM sleep disorder and neurodegeneration, scientists performed molecular neuroimaging using single photon emission computed tomography (SPECT). “Our SPECT study showed a trend toward decreased dopamine transporter density in the brain and Parkinsonism in the follow-up data of patients with REM sleep disorder who had no previous evidence of neurodegenerative disease,” said Hongyoon Choi, MD, a PhD candidate. A total of 21 consecutive patients with no known Parkinsonism or cognitive decline were enrolled in the long-term study between 2004 and 2006 and were followed after about eight years. Results showed that after follow-up, patients’ SPECT scans revealed substantial decreases in…
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Brain Activity Passes Through Newly Detected States to Regain Consciousness
Wednesday, June 25, 2014 9:00
After exposure to surgical anesthesia, electrical activity in the brain gradually returns to its conscious patterns. However, new research from Rockefeller University, reported in the Proceedings of the National Academy of Sciences, indicates that resuming consciousness is not a simple process. New findings suggest the anesthetized brain must pass through certain “way stations” on the path back to consciousness. Experiments on rats monitored the local field potentials (LFPs) in particular parts of the brain associated with wakefulness and anesthesia. These recordings gave researchers a sensitive handle on the activities of whole groups of neurons in particular parts of the thalamus and cortex. “Recordings from each animal wound up having particular features that spontaneously appeared, suggesting their brain activity was abruptly transitioning through particular states,” said Andrew Hudson, now an assistant professor in anesthesiology at the University of California, Los Angeles. “We analyzed the probability of a brain jumping from one state to another, and we found that certain states act as hubs through which the brain must pass to continue on its way to consciousness.”…
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Fungal Protein Found to Cross Blood-brain Barrier
Tuesday, June 24, 2014 13:00
In a series of experiments on a fungus that causes cryptococcal meningitis, investigators at University of California Davis have isolated a protein that appears to be responsible for the fungus’ ability to cross from the bloodstream into the brain. The discovery, recently published online in mBio, has important implications for developing a more effective treatment for Cryptococcus neoformans, the cause of the condition, and other brain infections, as well as for brain cancers that are difficult to treat with conventional medications. “This study fills a significant gap in our understanding of how C. neoformans crosses the blood-brain barrier and causes meningitis,” said Angie Gelli, principal investigator of the study. “It is our hope that our findings will lead to improved treatment for this fungal disease, as well as other diseases of the central nervous system.” To learn more about the study, click here.
New Models for Testing Parkinson’s Disease Immune-based Drugs
Tuesday, June 24, 2014 9:00
A team of researchers from the Perelman School of Medicine at the University of Pennsylvania has demonstrated that immunotherapy with specifically targeted antibodies may block the development and spread of Parkinson’s disease (PD) in the brain. Recently reported in Cell Reports, the study demonstrates that the researchers prevented the development of pathology and also reversed some of the effects of already-existing disease by intercepting the distorted and misfolded alpha-synuclein (α-syn) proteins that enter and propagate in neurons. The animal study shows promise in developing new therapies for PD. To learn more about the study, click here.
Renal Measures Predict Stroke Risk
Monday, June 23, 2014 14:38
According to a MedPageToday article, a study recently reported online in Stroke indicated that two different measures of kidney disease severity were strongly associated with stroke risk. Albuminuria and a depressed estimated glomerular filtration rate were predictors of ischemic stroke, whereas only albuminuria was independently associated with risk of intraparenchymal hemorrhage. However, researchers found that the relationship between albuminuria and hemorrhage was significantly stronger than that between albuminuria and ischemic stroke. To learn more about the study, click here.
Study: Many Epilepsy Patients Who Fail to Take Medications Experience Depression
Friday, June 20, 2014 13:00
According to a new study, many patients who fail to take their antiseizure medications are suffering from depression — the first research to show a direct link between depression and medication nonadherence. Missing even one dose of an antiepileptic drug can cause breakthrough seizures, even in patients whose epilepsy is well controlled by medications. Yet studies have shown that 30 to 50 percent of people with epilepsy do not adhere to their medication regimen. For this study, researchers accessed a nationwide health plan/pharmacy database, and selected a sample of 10,000 epilepsy patients, 2,750 of whom were randomly selected and mailed an in-depth survey that included a number of validated questionnaires on medication adherence, depression status, seizure severity and frequency, and quality of life. The researchers then conducted a path analysis to determine the relationships between depression, drug adherence, seizure severity and quality of life. One key finding was that depression was significantly correlated with an elevated risk of antiepileptic drug nonadherence. Depression was also associated with low quality of life scores. In addition, those patients…
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Study Provides Insight into How the Brain Regulates Its Blood Flow
Friday, June 20, 2014 9:00
Researchers have demonstrated, for the first time, that the vascular endothelium plays a critical role in the regulation of blood flow in response to stimulation in the living brain. To tease apart the role of endothelial signaling in the living brain, they had to develop new ways to both image the brain at very high speeds, and also to selectively alter the ability of endothelial cells to propagate signals within intact vessels, which the team achieved through a range of techniques that use light and optics. Focused laser light was used in combination with a fluorescent dye within the bloodstream to cause oxidative damage to the inner endothelial layer of blood brain arterioles, while leaving the rest of the vessel intact and responsive. The team showed that, after damaging a small section of a vessel using their laser, the vessel no longer dilated beyond the damaged point. When the endothelium of a larger number of vessels was targeted in the same way, the overall blood flow response of the brain to stimulation was significantly decreased….
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Study: Brain Signals Link Fit Kids to Better Language Skills
Thursday, June 19, 2014 13:00
Children who are physically fit have faster and more robust neuro-electrical brain responses during reading than their less-fit peers, researchers report. The study, recently reported in Brain and Cognition, does not prove that higher fitness directly influences the changes seen in the electrical activity of the brain, the researchers say, but offers a potential mechanism to explain why fitness correlates so closely with better cognitive performance on a variety of tasks. Using electroencephalography, the researchers found that children who were more fit (as measured by oxygen uptake during exercise) had higher amplitude N400 and P600 waves than their less-fit peers when reading normal or nonsensical sentences. The N400 also had shorter latency in children who were more fit, suggesting that they processed the same information more quickly than their peers. Most importantly, the researchers said, these differences in brain activity corresponded to better reading performance and language comprehension in the children who were more fit. To learn more about the study, click here.
Sleep After Learning Strengthens Brain Cell Connections, Enhances Memory
Wednesday, June 18, 2014 16:30
In study recently published in Science, researchers report that sleep after learning encourages the growth of dendritic spines. Moreover, the activity of brain cells during slow-wave sleep after learning is critical for such growth. The findings of the animal study conducted at the New York University Langone Medical Center support the hypothesis that sleep helps consolidate and strengthen new memories, and show how learning and sleep cause physical changes in the motor cortex. Researchers used mice genetically engineered to express a fluorescent protein in neurons. Using a special laser-scanning microscope that illuminates the glowing fluorescent proteins in the motor cortex, the scientists were then able to track and image the growth of dendritic spines along individual branches of dendrites before and after mice learned to balance on a spin rod. After documenting that mice sprout new spines along dendritic branches, within six hours after training on the spinning rod, the researchers set out to understand how sleep would impact this physical growth. “Now we know that when we learn something new, a neuron will grow…
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