Posts tagged science
Articles and news from the latest research reports.
Neuroscientists are trying to work out why the brain does so much when it seems to be doing nothing at all.
For volunteers, a brain-scanning experiment can be pretty demanding. Researchers generally ask participants to do something — solve mathematics problems, search a scene for faces or think about their favoured political leaders — while their brains are being imaged.
But over the past few years, some researchers have been adding a bit of down time to their study protocols. While subjects are still lying in the functional magnetic resonance imaging (fMRI) scanners, the researchers ask them to try to empty their minds. The aim is to find out what happens when the brain simply idles. And the answer is: quite a lot.
A new study of the sense of smell lends support to a controversial theory of olfaction: Our noses can distinguish both the shape and the vibrational characteristics of odorant molecules.
The study, in the journal Physical Chemistry Chemical Physics, demonstrates the feasibility of the theory – first proposed decades ago – that the vibration of an odorant molecule’s chemical bonds – the wagging, stretching and rocking of the links between atoms – contributes to our ability to distinguish one smelly thing from another.
“The theory goes that when the right odorant binds to its receptor, the odorant’s molecular vibration allows electrons to transfer from one part of the receptor to another,” said University of Illinois physics and Beckman Institute professor Klaus Schulten, who conducted the analysis with postdoctoral researcher Ilia Solov’yov and graduate student Po-Yao Chang. “This electron transfer appears to fine-tune the signal the receptor receives.”
(Watch a video about the research.)
Teaching the Blind to Find Their Way by Playing Video Games
Computer based video games are receiving great interest as a means to learn and acquire new skills. As a novel approach to teaching navigation skills in the blind, we have developed Audio-based Environment Simulator (AbES); a virtual reality environment set within the context of a video game metaphor. Despite the fact that participants were naïve to the overall purpose of the software, we found that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building using audio based cues alone. This was confirmed by a series of behavioral performance tests designed to assess the transfer of acquired spatial information to a large-scale, real-world indoor navigation task. Furthermore, learning the spatial layout through a goal directed gaming strategy allowed for the mental manipulation of spatial information as evidenced by enhanced navigation performance when compared to an explicit route learning strategy. We conclude that the immersive and highly interactive nature of the software greatly engages the blind user to actively explore the virtual environment. This in turn generates an accurate sense of a large-scale three-dimensional space and facilitates the learning and transfer of navigation skills to the physical world.
Remember the telephone game where people take turns whispering a message into the ear of the next person in line? By the time the last person speaks it out loud, the message has radically changed. It’s been altered with each retelling.
Turns out your memory is a lot like the telephone game, according to a new Northwestern Medicine study.
Every time you remember an event from the past, your brain networks change in ways that can alter the later recall of the event. Thus, the next time you remember it, you might recall not the original event but what you remembered the previous time. The Northwestern study is the first to show this.
“A memory is not simply an image produced by time traveling back to the original event — it can be an image that is somewhat distorted because of the prior times you remembered it,” said Donna Bridge, a postdoctoral fellow at Northwestern University Feinberg School of Medicine and lead author of the paper on the study recently published in the Journal of Neuroscience. “Your memory of an event can grow less precise even to the point of being totally false with each retrieval.”
Pill Found Promising in Treatment of M.S.
A new oral medication to treat patients in the early stages of has shown considerable promise in two clinical trials, researchers announced on Wednesday.
The medication is on track to become just the third oral drug available to M.S. patients, and potentially the safest and most effective, experts said. The second oral drug, called Aubagio, was approved just last week.
M.S. was virtually untreatable only two decades ago, but today nine “disease modifying” drugs are available for early-stage patients; a half-dozen more are in the late stages of development. Most patients in the early stage of the disease, a form called relapsing-remitting M.S., take drugs by injection.
The two new studies, published online in The New England Journal of Medicine, found that the drug BG-12, developed by Biogen Idec, reduced relapse rates in patients with relapsing M.S. by about 50 percent. The drug also significantly reduced the frequency of new brain lesions often associated with these attacks, and slowed the progression of disease compared with a placebo.
The studies were Phase 3 trials, a last step on the road to drug approval. The Food and Drug Administration is required to make a decision about the drug’s approval before the end of this year.
“This drug is clearly quite effective in managing disease and reducing disability, and the safety profile looks quite good,” said Timothy Coetzee, the chief research officer at the National Multiple Sclerosis Society, who was not involved in the studies.
is often a progressive disease in which the immune system damages neurons in the brain and spinal cord. A majority of people with M.S. have relapsing-remitting M.S., characterized by flare-ups that cause lesions in the brain to develop and neurological symptoms to emerge or worsen. Eventually, more than half of patients develop a progressive form of M.S., leading to permanent disabilities.
Interferons, the drugs most commonly used in relapsing M.S., reduce relapses by about 30 percent, and have not been shown to slow the progression of the disease and disability. The newly approved Aubagio also reduces relapses by about 30 percent, and it has the advantage of being an oral drug.
Two drugs that are substantially more effective, and Gilenya, come with serious risks including, in rare cases, death. They are used as second-line treatments when an initial approach fails, and patients require some monitoring.
In the new studies, called Define and Confirm, patients were randomized into two groups, taking 240 milligrams of BG-12 either twice or three times a day. Patients in a third group took a placebo. The combined results showed that the drug reduced the relapse rate by about 50 percent. There was minimal difference between the twice-daily and thrice-daily regimens.
Taking BG-12 twice a day reduced the number of new or newly enlarging brain lesions by 71 percent to 99 percent, depending on the type of lesion and the study. The Define study found a statistically significant 38 percent reduction in the progression to disability.
The most frequent side effects were a temporary flushing and warm feeling and gastrointestinal symptoms including nausea, , cramping and . Though both types of side effects were common, they tended to diminish after the first few weeks of use and were tolerated by most patients.
BG-12 is an anti-inflammatory that works by protecting nerves against injury. It is a fumaric acid, very similar to one widely used in Germany for the treatment of . “The safety track record is well known and appears to be very strong,” said Dr. Robert Fox, lead author of one of the two new studies and medical director of the Mellen Center for Multiple Sclerosis Treatment and Research at the Cleveland Clinic.
“It’s a bright day for M.S. patients, but there is a gray cloud in that we still don’t have anything for those with progressive M.S.,” he added.
Neuroscientists at New York University have devised a method that has reduced several afflictions associated with Fragile X syndrome (FXS) in laboratory mice. Their findings, which are reported in the journal Neuron, offer new possibilities for addressing FXS, the leading inherited cause of autism and intellectual disability.
Those afflicted with FXS do not possess the protein FMRP, which is a suppressor of protein synthesis. Absent this suppressor, protein synthesis is exaggerated, producing a range of mental and physical disorders.
Previous research has indirectly targeted protein synthesis by seeking to temper, but not block, this process. The NYU researchers, by contrast, sought a more fundamental intervention—removing the enzyme, p70 ribosomal S6 kinase 1, or S6K1, which has previously been shown to regulate protein synthesis in FXS mice. By addressing this phenomenon at the molecular level, they hoped to diminish many of the conditions associated with FXS.
Findings Offer New Opportunity To Understand Connection Between Primary Brain Functions and Behavioral Patterns in Autism
New research led by Carnegie Mellon University neuroscientists takes the first step toward deciphering the connection between general brain function and the emergent behavioral patterns in autism. Published in the journal Neuron, the study shows that autistic adults have unreliable neural sensory responses to visual, auditory and somatosensory, or touch, stimuli. This poor response reliability appears to be a fundamental neural characteristic of autism.
"Within the autism research community, most researchers are looking for the location in the brain where autism happens," said Ilan Dinstein, a postdoctoral researcher in Carnegie Mellon’s Department of Psychology and lead author of the study. "We’re taking a different approach and thinking about how a general characteristic of the brain could be different in autism - and how that might lead to behavioral changes."
First extensive analysis of Allen Human Brain Atlas published in Nature has implications for basic understanding of the human brain and for medicine
Scientists at the Allen Institute for Brain Science reported in the latest issue of the journal Nature that human brains share a consistent genetic blueprint and possess enormous biochemical complexity. The findings stem from the first deep and large-scale analysis of the vast data set publicly available in the Allen Human Brain Atlas.
The results of this study are based on extensive analysis of the Allen Human Brain Atlas, specifically the detailed all-genes, all-structures survey of genes at work throughout the human brain. This dataset profiles 400 to 500 distinct brain areas per hemisphere using microarray technology and comprises more than 100 million gene expression measurements covering three individual human brains to date. Among other findings, these data show that 84% of all genes are expressed somewhere in the human brain and in patterns that are substantially similar from one brain to the next.
"This study demonstrates the value of a global analysis of gene expression throughout the entire brain and has implications for understanding brain function, development, evolution and disease," said Ed Lein, Ph.D., Associate Investigator at the Allen Institute for Brain Science and co-lead author on the paper. "These results only scratch the surface of what can be learned from this immense data set. We look forward to seeing what others will discover."
The party drug mephedrone can cause lasting damage to the brain, according to new research led by the University of Sydney.
"Mephedrone is highly addictive in the worst possible way. Users tend to binge on massive doses of the drug over short time spans," said Craig Motbey, a PhD candidate in the University’s School of Psychology and lead author of the research published in PLOS ONE, the Public Library of Science journal, today.
"Combined with the fact mephedrone is skyrocketing in popularity worldwide, with Australia following that trend, our finding that high doses can cause ongoing cognitive impairment spells a significant risk for users."
Also known as ‘meow meow’ and ‘MCAT’, mephedrone’s immediate effect on the brain is similar to a combination of ecstasy and methamphetamine.
"You get the euphoria and touchy-feeliness of ecstasy together with the intense addictiveness of methamphetamine or cocaine," said Motbey.
The current results, based upon experiments with laboratory rats, provide evidence of mephedrone’s ability to damage memory.
Scientists have discovered the first direct evidence that a biological mechanism long suspected in epilepsy is capable of triggering the brain seizures – opening the door for studies to seek improved treatments or even preventative therapies.
Researchers at Cincinnati Children’s Hospital Medical Center report Sept. 19 in Neuron that molecular disruptions in small neurons called granule cells – located in the dentate gyrus region of the brain – caused brain seizures in mice similar to those seen in human temporal lobe epilepsy. The dentate gyrus is in the hippocampus of the temporal lobe, and temporal lobe epilepsy is one of the most common forms of the disorder.
“Epilepsy is one of those rare disorders where we have no real preventative therapies, and current treatments after diagnosis can have significant side effects,” said Steven Danzer, PhD, principal investigator on the study and a neuroscientist in the Department of Anesthesia at Cincinnati Children’s. “Establishing which cells and mechanisms are responsible for the seizures allows us to begin working on ways to control or eliminate the problem therapeutically, and in a more precise manner.”