Researchers use magnetic pulses to brain to reduce overly optimistic tendencies
Scientists have known for many years that human beings, as a general rule, are an overly optimistic bunch. We close our eyes to statistics suggesting our eating habits may be killing us, ignore warnings about texting while driving and almost always believe things will come out all right in the end if we’ll just hang in there, despite sometimes obvious indications to the contrary. Research has suggested that two specific symmetrically opposite parts of the brain influence our optimism or pessimism, but until now haven’t been able to offer direct proof. Now however, new research by a group of neuroscientists has found, as they describe in their paper published in the Proceedings of the National Academy of Sciences, that turning off one of these areas via magnetic pulses dramatically reduces overly optimistic tendencies.
Filed under brain optimism pessimism TMS inferior frontal gyrus neuroscience psychology science
Researchers in the Taub Institute at Columbia University Medical Center (CUMC) have identified a mechanism that appears to underlie the common sporadic (non-familial) form of Parkinson’s disease, the progressive movement disorder. The discovery highlights potential new therapeutic targets for Parkinson’s and could lead to a blood test for the disease. The study, based mainly on analysis of human brain tissue, was published in the online edition of Nature Communications.
Studies of rare, familial (heritable) forms of Parkinson’s show that a protein called alpha-synuclein plays a role in the development of the disease. People who have extra copies of the alpha-synuclein gene produce excess alpha-synuclein protein, which can damage neurons. The effect is most pronounced in dopamine neurons, a population of brain cells in the substantia nigra that plays a key role in controlling normal movement and is lost in Parkinson’s. Another key feature of Parkinson’s is the presence of excess alpha-synuclein aggregates in the brain.
As the vast majority of patients with Parkinson’s do not carry rare familial mutations, a key question has been why these individuals with common sporadic Parkinson’s nonetheless acquire excess alpha-synuclein protein and lose critical dopamine neurons, leading to the disease.
Using a variety of techniques, including gene-expression analysis and gene-network mapping, the CUMC researchers discovered how common forms of alpha-synuclein contribute to sporadic Parkinson’s. “It turns out multiple different alpha-synuclein transcript forms are generated during the initial step in making the disease protein; our study implicates the longer transcript forms as the major culprits,” said study leader Asa Abeliovich, MD, PhD, associate professor of pathology and cell biology and neurology at CUMC. “Some very common genetic variants in the alpha-synuclein gene, present in many people, are known to impact the likelihood that an individual will suffer from sporadic Parkinson’s. In our study, we show that people with ‘bad’ variants of the gene make more of the elongated alpha-synuclein transcript forms. This ultimately means that more of the disease protein is made and may accumulate in the brain.”
“An unusual aspect of our study is that it is based largely on detailed analysis of actual patient tissue, rather than solely on animal models,” said Dr. Abeliovich. “In fact, the longer forms of alpha-synuclein are human-specific, as are the disease-associated genetic variants. Animal models don’t really get Parkinson’s, which underscores the importance of including the analysis of human brain tissue.”
“Furthermore, we found that exposure to toxins associated with Parkinson’s can increase the abundance of this longer transcript form of alpha-synuclein. Thus, this mechanism may represent a common pathway by which environmental and genetic factors impact the disease,” said Dr. Abeliovich.
The findings suggest that drugs that reduce the accumulation of elongated alpha-synuclein transcripts in the brain might have therapeutic value in the treatment of Parkinson’s. The CUMC team is currently searching for drug candidates and has identified several possibilities.
The study also found elevated levels of the alpha-synuclein elongated transcripts in the blood of a group of patients with sporadic Parkinson’s, compared with unaffected controls. This would suggest that a test for alpha-synuclein may serve as a biomarker for the disease. “There is a tremendous need for a biomarker for Parkinson’s, which now can be diagnosed only on the basis of clinical symptoms. The finding is particularly intriguing, but needs to be validated in additional patient groups,” said Dr. Abeliovich. A biomarker could also speed clinical trials by giving researchers a more timely measure of a drug’s effectiveness.
(Source: cumc.columbia.edu)
Filed under brain parkinson’s disease α-synuclein neuron neuroscience psychology science
Fly neurons could reveal the root of Alzheimer’s disease, says a TAU researcher
Ya’ara Saad, a PhD candidate in the lab of Prof. Amir Ayali at TAU’s Department of Zoology and the Sagol School of Neurosciences. is exploring how neural networks develop one neuron at a time. In the lab, the researchers break the fly’s nervous system down into single cells, separate these cells, then place them at a distance from each other in a Petri dish. After a few days, the neurons begin to grow towards one another and establish connections, and then migrate to form clusters of cells. Finally, they re-organize themselves to form a sophisticated network, says Saad. Because these experiments uniquely allow researchers to concentrate on individual neurons, they can perform specific measurements of proteins, note electrical activity, watch synapses develop, and see how physical changes take shape.
Saad and her fellow researchers are using this technique to observe how neurodegenerative diseases take over the neurons and to potentially test various medicinal interventions. In their experiments, one group of flies is genetically modified so that it expresses a peptide called Amyloid Beta, found in protein-based plaques of human Alzheimer’s disease patients. The results of these studies are then compared to those of a non-modified control group. Both strains of flies are provided by Prof. Daniel Segal of TAU’s Department of Molecular Microbiology and Biotechnology.
Previous studies performed on flies expressing Amyloid Beta showed that they demonstrate Alzheimer’s-like symptoms such as motor problems, impaired learning capabilities, and shorter lifespans. While this peptide has been researched for quite some time, scientists still do not know how it functions. Saad says her work may help unlock the mystery of this function. “Now I can really get into the molecular operation of Amyloid Beta inside the cell. I can watch the dysfunction in the synapses, monitor the proteins involved, and record electrical activity in a much more accessible way,” she says.
Filed under fruit flies brain neurodegenerative diseases alzheimer alzheimer's disease neuron neuroscience science
Humans aren’t the only animals who possess special skills with mugs
Paper wasps aren’t mammals, or even vertebrates. Before this study, the notion that a creature so distant from humankind in the tree of life could possess face expertise was weirder than an upside-down Darwin. Now the wasp development has added some sizzle to the endeavor of establishing what face-perception abilities other creatures may actually have. Emerging patterns in the animal world may reveal what drives the evolution of remarkable face prowess.
“The search is on,” says neuroscientist Winrich Freiwald of Rockefeller University in New York City.
While some researchers continue to invent tests (and debate how to interpret test results) for probing facial aptitudes among humankind’s primate cousins, other efforts have pushed beyond primates. Sheep, as well as those paper wasps, appear to have some special face skills. And faces may be important among rodents in ways that demand a more ticklish view of what face perception means. When it comes to face smarts, researchers are finding that the size of an animal’s brain may not matter as much as the company it keeps.
Filed under face perception face recognition golden paper wasp neuroscience paper wasp psychology brain science
Cochlear implants — electronic devices surgically implanted in the ear to help provide a sense of sound — have been successfully used since the late 1980’s. But questions remain as to whether bilateral cochlear implants, placed in each ear rather than the traditional single-ear implant, are truly able to facilitate binaural hearing. Now, Tel Aviv University researchers have proof that under certain conditions, this practice has the ability to salvage binaural sound processing for the deaf and hard-of-hearing.
According to Dr. Yael Henkin of TAU’s Department of Communication Disorders at the Stanley Steyer School of Health Professions and Head of The Hearing, Speech, and Language Center at Sheba Medical Center, and her colleagues Prof. Minka Hildesheimer, Yifat Yaar-Soffer, and Lihi Givon, the brain unites incoming sound from each ear at the brainstem through what is called “binaural processing.” “When we hear with both ears, we have an efficient auditory system,” she explains. Binaural processing provides improved ease of listening, sound localization, and the ability to understand speech in noisy surroundings.
In their study, the researchers looked at children who had lost their hearing at a young age and were not born deaf. Those who were provided with bilateral cochlear implants exhibited true binaural processing, similar to that of their normal hearing peers. In contrast, deaf-at-birth children who received their first cochlear implant at young age and their second after long delay, did not exhibit binaural processing.
The research was recently reported in the journal Cochlear Implants International.
Filed under brain cochlear implants hearing implants binaural processing neuroscience science
Surgeons at UC Davis Medical Center have successfully implanted a new telescope implant in the eye of a patient with end-stage age-related macular degeneration (AMD), the most advanced form of the disease and a leading cause of blindness in older Americans.
The device, approved by the Food and Drug Administration in 2010, is the only medical/surgical option available that restores a portion of vision lost to the disease. UC Davis Health System’s Eye Center, in collaboration with the Society for the Blind, is one of the few in California and the nation to offer the innovative procedure.
Filed under brain vision macular degeneration retina vision loss blindness ageing neuroscience science
A team of neuroscientists and chemists from the U.S. and China September 24 publish research suggesting that a class of currently used anti-cancer drugs as well as several previously untested synthetic compounds show effectiveness in reversing memory loss in two animal models of Alzheimer’s disease.
CSHL Professor Yi Zhong, Ph.D., who led the research conducted in fruit flies and mice, says he and his colleagues were surprised with their results, which, he stressed, used two independent experimental approaches “the results of which clearly converged.”
Specifically, the research converged on what Zhong’s team suggests is a “preferred target” for treating memory loss associated with the amyloid-beta (Aβ) plaques seen in advanced Alzheimer’s patients. That target is the epidermal growth factor receptor, often called by its acronym, EGFR.
Overexpression of the EGFR is a characteristic feature of certain cancers, notably a subset of lung cancers. Two targeted treatments, erlotinib (Tarceva) and gefitinib (Iressa), can dramatically, albeit transiently, reverse EGFR-positive cancers, by blocking the EGF receptor and thus preventing its activation.
The newly published research by Zhong’s team suggests that the signaling within cells that is induced by EGFR activation also plays a role in the pathology – still poorly understood – involved in Aβ-associated memory loss seen in Alzheimer’s patients.
Filed under brain alzheimer alzheimer disease memory amyloid-beta EGFR neuroscience science
With an incredible diversity of cell types, the central nervous system (CNS), comprising the brain, spinal cord and retina, can be considered to be the most complex organ in the body.
Professor Bill Harris, an experimental biologist and Head of the Department of Physiology, Development and Neuroscience, is fascinated by how this complex and sophisticated system is built out of a collection of undifferentiated cells.
By putting an advanced technology to novel use, he has been able to observe for the first time the entire process of retinal development at the cellular level in zebrafish embryos. This has achieved a long-sought goal in developmental neurobiology: a complete analysis of the building of a vertebrate CNS structure in vivo.
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Filed under brain neuroscience retina retinal development visual system zebrafish CNS science
Most people equate “gray matter” with the brain and its higher functions, such as sensation and perception, but this is only one part of the anatomical puzzle inside our heads. Another cerebral component is the white matter, which makes up about half the brain by volume and serves as the communications network.
The gray matter, with its densely packed nerve cell bodies, does the thinking, the computing, the decision-making. But projecting from these cell bodies are the axons—the network cables. They constitute the white matter. Its color derives from myelin—a fat that wraps around the axons, acting like insulation.
Alex Schelgel, first author on a paper in the August 2012 Journal of Cognitive Neuroscience, has been using the white matter as a landscape on which to study brain function. An important result of the research is showing that you can indeed “teach old dogs new tricks.” The brain you have as an adult is not necessarily the brain you are always going to have. It can still change, even for the better.
"This work is contributing to a new understanding that the brain stays this plastic organ throughout your life, capable of change," Schlegel says. "Knowing what actually happens in the organization of the brain when you are learning has implications for the development of new models of learning as well as potential interventions in cases of stroke and brain damage."
Schlegel is a graduate student working under Peter Tse, an associate professor of psychological and brain sciences and a coauthor on the paper. “This study was Peter’s idea,” Schlegel says. “He wanted to know if we could see white matter change as a result of a long-term learning process. Chinese seemed to him like the most intensive learning experience he could think of.”
Twenty-seven Dartmouth students were enrolled in a nine-month Chinese language course between 2007 and 2009, enabling Schlegel to study their white matter in action. While many neuroscientists use magnetic resonance imaging (MRI) in brain studies, Schlegel turned to a new MRI technology, called diffusion tensor imaging (DTI). He used DTI to measure the diffusion of water in axons, tracking the communication pathways in the brain. Restrictions in this diffusion can indicate that more myelin has wrapped around an axon.
"An increase in myelination tells us that axons are being used more, transmitting messages between processing areas," Schlegel says. "It means there is an active process under way."
Their data suggest that white matter myelination is precisely what was seen among the language students. There is a structural change that goes along with this learning process. While some studies have shown that changes in white matter occurred with learning, these observations were made in simple skill learning and strictly on a “before and after” basis.
"This was the first study looking at a really complex, long-term learning process over time, actually looking at changes in individuals as they learn a task," says Schlegel. "You have a much stronger causal argument when you can do that."
The work demonstrates that significant changes are occurring in adults who are learning. The structure of their brains undergoes change.
"This flies in the face of all these traditional views that all structural development happens in infancy, early in childhood," Schlegel says. "Now that we actually do have tools to watch a brain change, we are discovering that in many cases the brain can be just as malleable as an adult as it is when you are a child or an adolescent."
(Source: eurekalert.org)
Filed under brain learning plasticity white matter neuroscience psychology science
Using precisely-targeted lasers, researchers manipulate neurons in worms’ brains and take control of their behavior
In the quest to understand how the brain turns sensory input into behavior, Harvard scientists have crossed a major threshold. Using precisely-targeted lasers, researchers have been able to take over an animal’s brain, instruct it to turn in any direction they choose, and even to implant false sensory information, fooling the animal into thinking food was nearby.
As described in a September 23 paper published in Nature, a team made up of Sharad Ramanathan, an Assistant Professor of Molecular and Cellular Biology, and of Applied Physics, Askin Kocabas, a Post-Doctoral Fellow in Molecular and Cellular Biology, Ching-Han Shen, a Research Assistant in Molecular and Cellular Biology, and Zengcai V. Guo, from the Howard Hughes Medical Institute were able to take control of Caenorhabditis elegans – tiny, transparent worms – by manipulating neurons in the worms’ “brain.”
(Image credit: Ian D. Chin-Sang)
Filed under behavior brain caenorhabditis elegans neuron neuroscience science
