Posts tagged neuroscience
Articles and news from the latest research reports.
Rutgers Researchers Say Daily Drinking Can Be Risky
Study finds moderate consumption decreases number of new brain cells
Drinking a couple of glasses of wine each day has generally been considered a good way to promote cardiovascular and brain health. But a new Rutgers University study indicates that there is a fine line between moderate and binge drinking – a risky behavior that can decrease the making of adult brain cells by as much as 40 percent.
In a study posted online and scheduled to be published in the journal Neuroscience on November 8, lead author Megan Anderson, a graduate student working with Tracey J. Shors, Professor II in Behavioral and Systems Neuroscience in the Department of Psychology, reported that moderate to binge drinking – drinking less during the week and more on the weekends – significantly reduces the structural integrity of the adult brain.
“Moderate drinking can become binge drinking without the person realizing it,” said Anderson.“In the short term there may not be any noticeable motor skills or overall functioning problems, but in the long term this type of behavior could have an adverse effect on learning and memory.”
(Source: news.rutgers.edu)
Parkinson’s breakthough could slow disease progression
In an early-stage breakthrough, a team of Northwestern University scientists has developed a new family of compounds that could slow the progression of Parkinson’s disease.
Parkinson’s, the second most common neurodegenerative disease, is caused by the death of dopamine neurons, resulting in tremors, rigidity and difficulty moving. Current treatments target the symptoms but do not slow the progression of the disease.
The new compounds were developed by Richard B. Silverman, the John Evans Professor of Chemistry at the Weinberg College of Arts and Sciences and inventor of the molecule that became the well-known drug Lyrica, and D. James Surmeier, chair of physiology at Northwestern University Feinberg School of Medicine. Their research was published Oct. 23 in the journal Nature Communications.
The compounds work by slamming the door on an unwelcome and destructive guest — calcium. The compounds target and shut a relatively rare membrane protein that allows calcium to flood into dopamine neurons. Surmeier’s previously published research showed that calcium entry through this protein stresses dopamine neurons, potentially leading to premature aging and death. He also identified the precise protein involved — the Cav1.3 channel.
"These are the first compounds to selectively target this channel," Surmeier said. "By shutting down the channel, we should be able to slow the progression of the disease or significantly reduce the risk that anyone would get Parkinson’s disease if they take this drug early enough."
"We’ve developed a molecule that could be an entirely new mechanism for arresting Parkinson’s disease, rather than just treating the symptoms," Silverman said.
The compounds work in a similar way to the drug isradipine, for which a Phase 2 national clinical trial with Parkinson’s patients –- led by Northwestern Medicine neurologist Tanya Simuni, M.D. — was recently completed. But because isradipine interacts with other channels found in the walls of blood vessels, it can’t be used in a high enough concentration to be highly effective for Parkinson’s disease. (Simuni is the Arthur C. Nielsen Professor of Neurology at the Feinberg School and a physician at Northwestern Memorial Hospital.)
The challenge for Silverman was to design new compounds that specifically target this rare Cav1.3 channel, not those that are abundant in blood vessels. He and colleagues first used high-throughput screening to test 60,000 existing compounds, but none did the trick.
"We didn’t want to give up," Silverman said. He then tested some compounds he had developed in his lab for other neurodegenerative diseases. After Silverman identified one that had promise, Soosung Kang, a postdoctoral associate in Silverman’s lab, spent nine months refining the molecules until they were effective at shutting only the Cav1.3 channel.
In Surmeier’s lab, the drug developed by Silverman and Kang was tested by graduate student Gary Cooper in regions of a mouse brain that contained dopamine neurons. The drug did precisely what it was designed to do, without any obvious side effects.
"The drug relieved the stress on the cells," Surmeier said.
For the next step, the Northwestern team has to improve the pharmacology of the compounds to make them suitable for human use, test them on animals and move to a Phase 1 clinical trial.
"We have a long way to go before we are ready to give this drug, or a reasonable facsimile, to humans, but we are very encouraged," Surmeier said.
(Source: eurekalert.org)
Challenging Parkinson’s Dogma: Dopamine may not be the only key player in this tragic neurodegenerative disease
Scientists may have discovered why the standard treatment for Parkinson’s disease is often effective for only a limited period of time. Their research could lead to a better understanding of many brain disorders, from drug addiction to depression, that share certain signaling molecules involved in modulating brain activity.
A team led by Bernardo Sabatini, Takeda Professor of Neurobiology at Harvard Medical School, used mouse models to study dopamine neurons in the striatum, a region of the brain involved in both movement and learning. In people, these neurons release dopamine, a neurotransmitter that allows us to walk, speak and even type on a keyboard. When those cells die, as they do in Parkinson’s patients, so does the ability to easily initiate movement. Current Parkinson’s drugs are precursors of dopamine that are then converted into dopamine by cells in the brain.
The flip side of dopamine dearth is dopamine hyperactivity. Heroin, cocaine and amphetamines rev up or mimic dopamine neurons, ultimately reinforcing the learned reward of drug-taking. Other conditions such as obsessive-compulsive disorder, Tourette syndrome and even schizophrenia may also be related to the misregulation of dopamine.
In the October 11 issue of Nature, Sabatini and co-authors Nicolas Tritsch and Jun Ding reported that midbrain dopamine neurons release not only dopamine but also another neurotransmitter called GABA, which lowers neuronal activity. The previously unsuspected presence of GABA could explain why restoring only dopamine could cause initial improvements in Parkinson’s patients to eventually wane. And if GABA is made by the same cells that produce other neurotransmitters, such as depression-linked serotonin, similar single-focus treatments could be less successful for the same reason.
“If what we found in the mouse applies to the human, then dopamine’s only half the story,” said Sabatini.
Researchers Identify Area of the Brain That Processes Empathy
An international team led by researchers at Mount Sinai School of Medicine in New York has for the first time shown that one area of the brain, called the anterior insular cortex, is the activity center of human empathy, whereas other areas of the brain are not. The study is published in the September 2012 issue of the journal Brain.
Empathy, the ability to perceive and share another person’s emotional state, has been described by philosophers and psychologists for centuries. In the past decade, however, scientists have used powerful functional MRI imaging to identify several regions in the brain that are associated with empathy for pain. This most recent study, however, firmly establishes that the anterior insular cortex is where the feeling of empathy originates.
“Now that we know the specific brain mechanisms associated with empathy, we can translate these findings into disease categories and learn why these empathic responses are deficient in neuropsychiatric illnesses, such as autism,” said Patrick R. Hof, MD, Regenstreif Professor and Vice-Chair, Department of Neuroscience at Mount Sinai, a co-author of the study. “This will help direct neuropathologic investigations aiming to define the specific abnormalities in identifiable neuronal circuits in these conditions, bringing us one step closer to developing better models and eventually preventive or protective strategies.”
“Grassroots” Neurons Wire and Fire Together for Dominance in the Brain
Inside the brain, an unpredictable race—like a political campaign—is being run. Multiple candidates, each with a network of supporters, have organized themselves into various left- and right-wing clusters—like grassroots political teams working feverishly to reinforce a vision that bands them together. While scientists know that neurons in the brain anatomically organize themselves into these network camps, or clusters, the implications of such groupings on neural dynamics have remained unclear until now.
Using mathematical modeling, two researchers from the University of Pittsburgh have found that neurons team up together to sway particular outcomes in the brain and take over the nervous system in the name of their preferred action or behavior. The findings will be published in the November print issue of Nature Neuroscience.
“Through complex mathematical equations, we organized neurons into clustered networks and immediately saw that our model produced a rich dynamic wherein neurons in the same groups were active together,” said Brent Doiron, assistant professor of mathematics.
Brainwave Training Boosts Network for Cognitive Control and Predicts Mind Wandering
A breakthrough study conducted in Canada has found that training of the well-known brainwave in humans, the alpha rhythm, enhances a brain network responsible for cognitive-control which correlates with reductions in mind-wandering. The training technique, termed neurofeedback, is being considered as a promising method for restoring brain function in mental disorders. Using several neuroimaging methods, a team of researchers working at the University of Western Ontario have now uncovered that functional changes within a key brain network occur directly after a 30-minute session of noninvasive, neural-based training. Dysfunction of this cognitive-control network has previously been implicated in a range of brain disorders including attentional deficit hyperactivity disorder, schizophrenia, depression and post-traumatic stress disorder.
Brain waves reveal video game aptitude
Scientists report that they can predict who will improve most on an unfamiliar video game by looking at their brain waves. They describe their findings in a paper in the journal Psychophysiology.
The researchers used electroencephalography (EEG) to peek at electrical activity in the brains of 39 study subjects before they trained on Space Fortress, a video game developed for cognitive research. The subjects whose brain waves oscillated most powerfully in the alpha spectrum (about 10 times per second, or 10 hertz) when measured at the front of the head tended to learn at a faster rate than those whose brain waves oscillated with less power, the researchers found. None of the subjects were daily video game players.
The EEG signal was a robust predictor of improvement on the game, said University of Illinois postdoctoral researcher and Beckman Fellow Kyle Mathewson, who led the research with psychology professors and Beckman Institute faculty members Monica Fabiani and Gabriele Gratton.
“By measuring your brain waves the very first time you play the game, we can predict how fast you’ll learn over the next month,” Mathewson said. The EEG results predicted about half of the difference in learning speeds between study subjects, he said.
MRI research sheds new light on nerve fibres in the brain
World-leading experts in Magnetic Resonance Imaging from The University of Nottingham’s Sir Peter Mansfield Magnetic Resonance Centre have made a key discovery which could give the medical world a new tool for the improved diagnosis and monitoring of neuro-degenerative diseases like multiple sclerosis.
The new study, published in the Proceedings of the National Academy of Science, reveals why images of the brain produced using the latest MRI techniques are so sensitive to the direction in which nerve fibres run.
The white matter of the brain is made up of billions of microscopic nerve fibres that pass information in the form of tiny electrical signals. To increase the speed at which these signals travel, each nerve fibre is encased by a sheath formed from a fatty substance, called myelin. Previous studies have shown that the appearance of white matter in magnetic resonance images depends on the angle between the nerve fibres and the direction of the very strong magnetic field used in an MRI scanner.
Placebo’s Effect May Depend on Your Genes
Your response to placebos, or dummy medicine, may depend on your genes, according to a new study.
People with a gene variant that codes for higher levels of the brain chemical dopamine respond better to placebos than those with the low-dopamine version.
The findings, reported online Oct. 23 in the journal PLoS One, could help researchers design medical studies that distinguish the placebo response from the underlying effect of a medicine — the real aim of drug trials.
Researchers Find That Diabetes Drug Could Be Effective in Treating Addiction
Vanderbilt researchers are reporting today that a drug currently used to treat type 2 diabetes could be just as effective in treating addiction to drugs, including cocaine.
The findings, published online as a Letter To The Editor in the journal Molecular Psychiatry, could have far-reaching implications for patients worldwide who suffer from addiction.
“What we have demonstrated is that a brain mechanism already known to be therapeutic for the treatment of diabetes also appears to be implicated in at least certain types of drug addiction,” said Gregg Stanwood, Ph.D., assistant professor of Pharmacology and an investigator within the Vanderbilt Kennedy Center and Vanderbilt Brain Institute.
“We found that this drug called Exendin-4 that is already used for the medical management of diabetes, reduces the rewarding effects of cocaine in animals. We suspect that this is a general mechanism that will translate to additional drugs of abuse, especially other stimulants like amphetamine and methamphetamine.”
Co-author Aurelio Galli, Ph.D., professor of Molecular Physiology and Biophysics and Vanderbilt Brain Institute investigator, said Exendin-4 is already FDA-approved for diabetes (Byetta and Bydureon), so this target isn’t just “druggable” – it’s already “drugged.”
“I think the power of this research is that it is so easily translatable to humans because it is already FDA approved,” said Galli, also co-director of the Neuroscience Program in Substance Abuse (N-PISA) at Vanderbilt University. “This is the first indication that it will work on psychostimulants. So our studies offer immediate translational opportunities to improve outcomes in human abusers.”