Posts tagged neuroscience
Articles and news from the latest research reports.
Hand-held 3D scanner could simplify medical imaging
Although there are various efforts under way to create a working Star Trek-like medical tricorder, such a device isn’t available for general use just yet. In the meantime, however, doctor’s offices may soon be equipped a piece of equipment that wouldn’t look at all out of place in the sick bay of the Enterprise. Developed by engineers from the University of Illinois at Urbana-Champaign, it’s a hand-held scanning device that provides real-time three-dimensional images of the insides of patients’ bodies.
The scanner utilizes optical coherence tomography (OCT), which has been described as “optical ultrasound,” in that it uses reflected light – as opposed to reflected sound – to image internal structures. Along with an OCT system, the device also incorporates a near-infrared light source, a video camera for obtaining images of surface features at the scan location, and a microelectromechanical systems (MEMS)-based scanner for directing the light.
A novel function for p27 protein in the control of interneuron migration in the developing cerebral cortex
These results by GIGA-Neurosciences researchers (University of Liège, Belgium) increase our understanding of the mechanisms that drive neuronal migration in the cerebral cortex. Disruption of neuronal migration is associated with various neurological disorders characterized by mental retardation, epilepsy, learning disabilities, or autism.
In a study published in Developmental Cell, the group of Laurent Nguyen, Research Associate of the FRS-FNRS and WELBIO investigator at GIGA-Neurosciences (University of Liège) has discovered a novel function for p27 in the control of interneuron migration in the developing cerebral cortex.
The Connectome Debate: Is Mapping the Mind of a Worm Worth It?
In the 1970s biologist Sydney Brenner and his colleagues began preserving tiny hermaphroditic roundworms known as Caenorhabditis elegans in agar and osmium fixative, slicing up their bodies like pepperoni and photographing their cells through a powerful electron microscope. The goal was to create a wiring diagram—a map of all 302 neurons in the C. elegans nervous system as well as all the 7,000 connections, or synapses, between those neurons. In 1986 the scientists published a near complete draft of the diagram. More than 20 years later, Dmitri Chklovskii of Janelia Farm Research Campus and his collaborators published an even more comprehensive version. Today, scientists call such diagrams “connectomes.”
So far, C. elegans is the only organism that boasts a complete connectome. Researchers are also working on connectomes for the fruit fly nervous system and the mouse brain. In recent years some neuroscientists have proposed creating a connectome for the entire human brain—or at least big chunks of it. Perhaps the most famous proponent of connectomics is Sebastian Seung of the Massachusetts Institute of Technology, whose impressive credentials, TED talk, popular book, charisma and distinctive fashion sense (he is known to wear gold sneakers) have made him a veritable neuroscience rock star.
New research model to aid search for degenerative disease cures
Efforts to treat disorders like Lou Gehrig’s disease, Paget’s disease, inclusion body myopathy and dementiawill receive a considerable boost from a new research model created by UC Irvine scientists.
The team, led by pediatrician Dr. Virginia Kimonis, has developed a genetically modified mouse that exhibits many of the clinical features of human diseases largely triggered by mutations in the valosin-containing protein.
The mouse model will let researchers study how these now-incurable, degenerative disorders progress in vivo and will provide a platform for translational studies that could lead to lifesaving treatments.
“Currently, there are no effective therapies for VCP-associated diseases and related neurodegenerative disorders,” said Kimonis, a professor of pediatrics who specializes in genetics and metabolism. “This model will significantly spark new approaches to research directed toward the creation of novel treatment strategies.”
She and her team reported their discovery Sept. 28 online in PLOS ONE, a peer-reviewed, open-access journal.
The UCI researchers – from pediatrics, neurology, pathology and radiological sciences – specifically bred the first-ever “knock-in” mouse in which the normal VCP gene was substituted with one containing the common R155H mutation seen in humans with VCP-linked diseases. Subsequently, these mice exhibited the same muscle, brain and spinal cord pathology and bone abnormalities as these patients.
VCP is part of a system that maintains cell health by breaking down and clearing away old and damaged proteins that are no longer necessary. Mutations in the VCP gene disrupt the demolition process, and, as a result, excess and abnormal proteins may build up in muscle, bone and brain cells. These proteins form clumps that interfere with the cells’ normal functions and can lead to a range of disorders.
Another study carried out by members of this group – and published in August in the journal Cell Death & Disease – made use of these genetically altered mice to examine the development of Lou Gehrig’s disease, or ALS. The researchers, led by Dr. Hong Yin and Dr. John Weiss in UCI’s Department of Neurology, documented slow, extensive pathological changes in the spinal cord remarkably similar to changes observed in other animal models of ALS as well as in human patients. ALS research is currently limited by a paucity of animal models in which disease processes can be studied.
Genetically modified mice have become important research models in the effort to cure human ailments. Mice bred to exhibit the brain pathology of Alzheimer’s disease, for example, have dramatically sped up the race to advance new treatments – one such model was developed at UCI. And many cancer therapies were created and tested using genetically altered mice.
(Source: today.uci.edu)
Study Suggests Immune System Can Boost Nerve Regrowth
Modulating immune response to injury could accelerate the regeneration of severed peripheral nerves, a new study in an animal model has found. By altering activity of the macrophage cells that respond to injuries, researchers dramatically increased the rate at which nerve processes regrew.
Influencing the macrophages immediately after injury may affect the whole cascade of biochemical events that occurs after nerve damage, potentially eliminating the need to directly stimulate the growth of axons using nerve growth factors. If the results of this first-ever study can be applied to humans, they could one day lead to a new strategy for treating peripheral nerve injuries that typically result from trauma, surgical resection of tumors or radical prostectomy.
“Both scar formation and healing are the end results of two different cascades of biological processes that result from injuries,” said Ravi Bellamkonda, Carol Ann and David D. Flanagan professor in the Wallace H. Coulter Department of Biomedical Engineering and member of the Regenerative Engineering and Medicine Center at Georgia Tech and Emory University. “In this study, we show that by manipulating the immune system soon after injury, we can bias the system toward healing, and stimulate the natural repair mechanisms of the body.”
Beyond nerves, researchers believe their technique could also be applied to help regenerate other tissue – such as bone. The research was supported by the National Institutes of Health (NIH), and reported online Sept. 26, 2012, by the journal Biomaterials.
Using a high-tech imaging process to measure the thickness of the eye’s retina may one day predict the progression of multiple sclerosis, a new study suggests.
The finding might lead to better ways to judge the effectiveness of treatments because different parts of the retina seem to indicate different aspects of the disease and the toll it takes on different parts of the brain, the researchers said.
The report was published online Oct. 1 in the Archives of Neurology.
Intelligence Is in the Genes, but Where?
You can thank your parents for your smarts—or at least some of them. Psychologists have long known that intelligence, like most other traits, is partly genetic. But a new study led by psychological scientist Christopher Chabris of Union College reveals the surprising fact that most of the specific genes long thought to be linked to intelligence probably have no bearing on one’s IQ. And it may be some time before researchers can identify intelligence’s specific genetic roots.
Chabris and David Laibson, a Harvard economist, led an international team of researchers that analyzed a dozen genes using large data sets that included both intelligence testing and genetic data.
In nearly every case, the researchers found that intelligence could not be linked to the specific genes that were tested. The results are published online in Psychological Science, a journal of the Association for Psychological Science.
“In all of our tests we only found one gene that appeared to be associated with intelligence, and it was a very small effect. This does not mean intelligence does not have a genetic component. It means it’s a lot harder to find the particular genes, or the particular genetic variants, that influence the differences in intelligence,” said Chabris.
New Definition of Autism in Updated Psychiatric Clinical Manual Will Not Exclude Most Children with Autism
Parents should not worry that proposed changes to the medical criteria redefining a diagnosis of autism will leave their children excluded and deemed ineligible for psychiatric and medical care, says a team of researchers led by psychologists at Weill Cornell Medical College.
Their new study, published in the October 1 issue of the American Journal of Psychiatry, is the largest to date that has tried to unpack the differences between the diagnostic criteria for autism spectrum disorders in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the proposed revision in the fifth edition (DSM-5), which is expected to be published in May 2013. These manuals provide diagnostic criteria for people seeking mental-health-related medical services.
"I know that parents worry, but I don’t believe there is any substantial reason to fear that children who need to be diagnosed with autism spectrum disorders, and provided with vital services, will not be included in the new criteria in this updated manual," says the study’s senior investigator, Dr. Catherine Lord, director of the Center for Autism and the Developing Brain at NewYork-Presbyterian Hospital’s Westchester campus, along with its affiliated medical schools Weill Cornell Medical College and Columbia University College of Physicians and Surgeons.
At issue is whether DSM-5 will “capture” the same individuals diagnosed with different forms of autism by the DSM-IV. The DSM-5 proposal redefines autism as a single category — autism spectrum disorder (ASD) — whereas DSM-IV had multiple categories and included Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS).
Critics have particularly worried that among the excluded will be children now diagnosed with PPD-NOS and Asperger’s disorder. That isn’t the case, says Dr. Lord, who is also a DeWitt Wallace Senior Scholar at Weill Cornell and an attending psychologist at NewYork-Presbyterian Hospital. The study, the largest to date and arguably, the most rigorous, finds that when relying on parent report, 91 percent of the 4,453 children in the sample currently diagnosed with a DSM-IV autism spectrum disorder would be diagnosed with ASD using DSM-V.
Many of the remaining nine percent would likely be reincluded once a clinician can offer input, says Dr. Lord, who is also a member of the American Psychiatric Association’s DSM-5 Neurodevelopmental Disorders Work Group.
The study researchers also concluded that DSM-5 has higher specificity than DSM-IV—in their study, DSM-5 criteria resulted in fewer misclassifications.
(Source: weill.cornell.edu)
University of Miami researchers find that babies’ non-verbal communication skills can help predict outcomes in children at high risk of developing Autism
Approximately 19 percent of children with a sibling diagnosed with Autism Spectrum Disorder (ASD) will develop Autism due to shared genetic and environmental vulnerabilities, according to previous studies. For that reason, University of Miami (UM) psychologists are developing ways to predict the occurrence of ASD in high-risk children, early in life, in hopes that early intervention will lead to better outcomes in the future. Their findings are published in the journal Infancy.
The study is one of the first to show that measures of non-verbal communication in children, as young as eight months of age, predict autism symptoms that become evident by the third year of life. The results suggest that identifying children, who are having difficulties early enough, can enhance the effects of interventions.
The Obese Brain May Thwart Weight Loss
New research by Terry Davidson, director of American University’s Center for Behavioral Neuroscience, indicates that diets that lead to obesity—diets high in saturated fat and refined sugar—may cause changes to the brains of obese people that in turn may fuel overconsumption of those same foods and make weight loss more challenging.
“It is a vicious cycle that may explain why obesity is so difficult to overcome,” said Davidson, also a professor of psychology at AU.
Davidson recently published his research, “The Effects of a High-Energy Diet on Hippocampal-Dependent Discrimination Performance and Blood-Brain Barrier Integrity Differ for Diet-Induced Obese and Diet-Resistant Rats,” in the journal Physiology & Behavior.