Posts tagged science
Articles and news from the latest research reports.
Can you feel my pain? Middle-aged women sure can
Looking for someone to feel your pain? Talk to a woman in her 50s.
According to a new study of more than 75,000 adults, women in that age group are more empathic than men of the same age and than younger or older people.
"Overall, late middle-aged adults were higher in both of the aspects of empathy that we measured," said Sara Konrath, assistant research professor at the University of Michigan Institute for Social Research and co-author of an article on age and empathy forthcoming in the Journals of Gerontology: Psychological and Social Sciences.
"They reported that they were more likely to react emotionally to the experiences of others, and they were also more likely to try to understand how things looked from the perspective of others."
Konrath and colleagues Ed O’Brien and Linda Hagen of U-M and Daniel Grühn of North Carolina State University analyzed data on empathy from three separate large samples of American adults, two of which were taken from the nationally representative General Social Survey.
They found consistent evidence of an inverted U-shaped pattern of empathy across the adult life span, with younger and older adults reporting less empathy and middle-aged adults reporting more.
According to O’Brien, U-M doctoral student in social psychology, this pattern may result because increasing levels of cognitive abilities and experience improve emotional functioning during the first part of the adult life span, while cognitive declines diminish emotional functioning in the second half.
But more research is needed in order to understand whether this pattern is really the result of an individual’s age, or whether it is a generational effect reflecting the socialization of adults who are now in late middle age.
Parasites and poor antenatal care are the main causes of epilepsy in sub-Saharan Africa
Epilepsy is one of the most common neurological conditions worldwide, and it is well known that it is significantly more prevalent in poorer countries and rural areas. The study of more than half a million people in five countries of sub-Saharan Africa is the first to reveal the true extent of the problem and the impact of different risk factors.
The study - conducted at International Network for the Demographic Evaluation of Populations and Their Health (INDEPTH) demographic surveillance sites in Kenya, South Africa, Uganda, Tanzania and Ghana - screened 586 607 residents and identified 1711 who were diagnosed as having active convulsive epilepsy.
These individuals, along with 2033 who did not have epilepsy, were given a questionnaire to complete about their lifestyle habits. The team also took blood samples to test for exposure to malaria, HIV and four other parasitic diseases that are common in low-income countries.
The team found that adults who had been exposed to parasitic diseases were 1.5 to 3 times more likely to have epilepsy than those who had not. Epilepsy has previously been linked with various parasite infections, but this is the first study to reveal the extent of the problem.
Professor Charles Newton from the Wellcome Trust programme at the Kenyan Medical Research Institute (KEMRI) and the Department of Psychiatry at Oxford University, who led the study, said: “This study demonstrates that many cases of epilepsy could be entirely preventable with elimination of parasites in Africa, some of which - for example, onchocerciasis - have been controlled in some areas. In some areas the incidence of epilepsy could be reduced by 30-60 per cent with appropriate control measures.”
In children, the greatest risk factors for developing epilepsy were complications associated with delivery and head injury. Interventions to improve antenatal and perinatal care could substantially reduce the prevalence of epilepsy in this region, say the authors.
The study focused on people with convulsive epilepsies as they are the most reliably detected and reported and there remains a substantial stigma attached to patients with the disease.
“Facilities for diagnosis, treatment and ongoing management of epilepsy are virtually non-existent in many of the world’s poorest regions, so it’s vital that we take these simple steps to try and prevent as many cases of this debilitating disease as possible,” Professor Newton added.
The findings were published today in the journal ‘Lancet Neurology’. The study was funded by the Wellcome Trust, with support from the University of the Witwatersrand and the South African Medical Research Council.
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Scientists Uncover a Previously Unknown Mechanism of Memory Formation
It takes a lot to make a memory. New proteins have to be synthesized, neuron structures altered. While some of these memory-building mechanisms are known, many are not. Some recent studies have indicated that a unique group of molecules called microRNAs, known to control production of proteins in cells, may play a far more important role in memory formation than previously thought.
Now, a new study by scientists on the Florida campus of The Scripps Research Institute has for the first time confirmed a critical role for microRNAs in the development of memory in the part of the brain called the amygdala, which is involved in emotional memory. The new study found that a specific microRNA—miR-182—was deeply involved in memory formation within this brain structure.
“No one had looked at the role of microRNAs in amygdala memory,” said Courtney Miller, a TSRI assistant professor who led the study. “And it looks as though miR-182 may be promoting local protein synthesis, helping to support the synapse-specificity of memories.”
In the new study, published in the Journal of Neuroscience, the scientists measured the levels of all known microRNAs following an animal model of learning. A microarray analysis, which enables rapid genetic testing on a large scale, showed that more than half of all known microRNAs are expressed in the amygdala. Seven of those microRNAs increased and 32 decreased when learning occurred.
The study found that, of the microRNAs expressed in the brain, miR-182 had one of the lowest levels and these decreased further with learning. Despite these very low levels, its overexpression prevented the formation of memory and led to a decrease in proteins that regulate neuronal plasticity (neurons’ ability to adapt) through changes in structure.
These findings suggest that learning-induced suppression of miR-182 is a main supporting factor in the formation of long-term memory in the amagdala, as well as an underappreciated mechanism for regulating protein synthesis during memory consolidation, Miller said.
Further analysis identified miR-182 as a repressor of proteins that control actin—a major component of the cytoskeleton, the scaffolding that holds cells together.
“We know that memory formation requires changes in dendritic spines on the neurons through regulation of the actin cytoskeleton,” Miller said. “When miR-182 is suppressed through learning it halts, at least in part, repression of actin-regulating proteins, so there’s a good chance that miR-182 exerts important control over the actin cytoskeleton.”
Miller is now interested in whether or not high levels of miR-182 accumulate in the aging brain, something that would help to explain a tendency toward memory loss in the elderly. She also notes that other research has shown that animal models lacking miR-182 had no significant physical or cellular abnormalities, suggesting that miR-182 could be a viable target for drug discovery.
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New drug target identified for multiple sclerosis and Alzheimer’s disease
Researchers at Boston University School of Medicine (BUSM) led by Carmela Abraham, PhD, professor of biochemistry, along with Cidi Chen, PhD, and other collaborators, report that the protein Klotho plays an important role in the health of myelin, the insulating material allowing for the rapid communication between nerve cells. These findings, which appear online in Journal of Neuroscience, may lead to new therapies for multiple sclerosis (MS) and Alzheimer’s disease (AD), in which white matter abnormalities are also common but have been largely ignored.
MS is an inflammatory disease which damages the fatty myelin sheaths around the axons of the brain and spinal cord. This destruction, loss or scarring of the sheaths results in a broad spectrum of symptoms. Disease onset usually occurs in young adults, most commonly women.
In MS the myelin is attacked by the immune system and may not be completely restored by myelin-producing cells (mature oligodendrocytes). The researchers discovered that the addition of Klotho protein to immature oligodendrocytes causes them to mature and manufacture proteins needed for the production of healthy myelin.
"These results taken together indicate that Klotho could become a drug target for multiple sclerosis and other white matter diseases, including AD," explained Abraham.
Abraham and her colleagues have identified, and are working on optimizing, a number of small molecules that could form the basis for the development of therapeutic drugs, which would increase the amount of Klotho protein in the brain.
Since Klotho is not only an age suppressor but also a tumor suppressor, as shown by other research groups, interventions with Klotho-enhancing drugs may solve some of the most treatment-resistant human ailments according to Abraham.
Klotho was named after the Greek Goddess and daughter of Zeus, who spins the thread of life. Abraham’s lab was the first to publish (in 2008) that Klotho levels in the brain decrease with age.
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Androgenic hormones could help treat multiple sclerosis
Testosterone and its derivatives could constitute an efficient treatment against myelin diseases such as multiple sclerosis, reveals a study by researchers from the Laboratoire d’Imagerie et de Neurosciences Cognitives (CNRS/Université de Strasbourg), in collaboration in particular with the “Neuroprotection et Neurorégénération: Molécules Neuroactives de Petite Taille” unit (Inserm/Université Paris-Sud). Myelin composes the sheaths that protect the nerve fibers and allow the speed of nerve impulses to be increased. A deficit in the production of myelin or its destruction cause serious illnesses for which there is no curative treatment. The researchers have shown that in mice brains whose nerve fibers have been demyelinated, testosterone and a synthetic analog induce the regeneration of oligodendrocytes, the cells responsible for myelination, and that they stimulate remyelination. This work is published on January in the journal Brain.
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Brain activity study lends insight into schizophrenia
Magnetic fields produced by the naturally occurring electrical currents in the brain could potentially be used as an objective test for schizophrenia and help to better understand the disease, according to new research published today.
A team of researchers from Plymouth and Spain have used the non-invasive magnetoencephalogram (MEG) technique to find two spectral features that are significantly different in schizophrenia patients compared to healthy control subjects.
Furthermore, they found that there were four spectral features in the brain signals of schizophrenia patients that changed with age compared to healthy control subjects, suggesting that schizophrenia affects the way in which brain activity evolves with age.
The study has been published today, Thursday 31 January, in the journal Physiological Measurement.
Schizophrenia is a serious psychiatric disorder, usually starting in late adolescence, which is characterised by a range of positive and negative symptoms, including hallucinations, delusions, paranoia, cognitive impairment, social withdrawal, self-neglect and loss of motivation and initiative.
It has no objective test and is currently diagnosed by clinicians who assess patients using a defined set of criteria.
Lead author of the study Dr Javier Escudero said: “At present, there is no blood, cerebrospinal fluid, brain imaging or neurophysiological test for schizophrenia in routine clinical practice. The diagnosis relies on the interpretation of symptoms and clinical history according to consensus criteria.
"The advent of an objective marker for schizophrenia would significantly facilitate the diagnosis and offer a better understanding of the neurobiological basis of the disease."
In this study, the frequency spectrum of the MEG background activity was analysed in 15 schizophrenia patients with positive symptoms and 17 age-matched healthy control subjects.
A range of spectral features from the MEGs were analysed to provide a holistic view of the brain activity of each subject. The MEG produced 148 values for each subject, which were subsequently divided into five different groups representing different parts of the brain, and were statistically analysed.
The researchers also investigated whether the spectral features could be used to distinguish between schizophrenia patients and the healthy controls. They showed that they were able to classify patients with 71 per cent accuracy.
"The long-term vision is to develop a low-cost, non-invasive and objective test to aid the diagnosis of this and other brain diseases. The magnetoencephalogram is able to provide very detailed information about the brain activity; however, it is expensive. Therefore, we aim to transfer these developments to electroencephalogram recordings in the future, as this technique meets those requirements of reduced cost, high availability and non-invasiveness," continued Dr Escudero.
(Image: Shutterstock)
Scientists learn more about how inhibitory brain cells get excited
Scientists have found an early step in how the brain’s inhibitory cells get excited. A natural balance of excitement and inhibition keeps the brain from firing electrical impulses randomly and excessively, resulting in problems such as schizophrenia and seizures. However excitement is required to put on the brakes.
“When the inhibitory neuron is excited, its job is to suppress whatever activity it touches,” said Dr. Lin Mei, Director of the Institute of Molecular Medicine and Genetics at the Medical College of Georgia at Georgia Regents University and corresponding author of the study in Nature Neuroscience.
Mei and his colleagues found that the protein erbin, crucial to brain development, is critical to the excitement.
The skin is a human being’s largest sensory organ, helping to distinguish between a pleasant contact, like a caress, and a negative sensation, like a pinch or a burn. Previous studies have shown that these sensations are carried to the brain by different types of sensory neurons that have nerve endings in the skin. Only a few of those neuron types have been identified, however, and most of those detect painful stimuli. Now biologists at the California Institute of Technology (Caltech) have identified in mice a specific class of skin sensory neurons that reacts to an apparently pleasurable stimulus.
More specifically, the team, led by David J. Anderson, Seymour Benzer Professor of Biology at Caltech, was able to pinpoint individual neurons that were activated by massage-like stroking of the skin. The team’s results are outlined in the January 31 issue of the journal Nature.
RIKEN, OIST Dive into Human Brain Project
One of the major frontiers of modern science is a comprehensive understanding of the human brain and its functions to guide the development of new technologies in information and communication. In a major announcement for the globalization of science, two Japanese research organizations, the Okinawa Institute of Science and Technology Graduate University (OIST) and RIKEN, will join forces with a large European consortium on the Human Brain Project (HBP), which the European Commission has officially announced as one of two Future and Emerging Technology (FET) Flagship projects. The new project will federate international efforts to understand and simulate the human brain for the creation of new technological advances for society.
The goal of the Human Brain Project is to combine all existing knowledge about the human brain and to reconstruct the brain, piece by piece, in supercomputer-based models and simulations. The models will offer the prospect of a new understanding of the human brain and its diseases and of completely new computing and robotics technologies. On January 28, the European Commission supported this vision, announcing that it has selected the HBP as one of two projects to be funded through the new FET Flagship Program. With more than 80 European and international research institutions, the Human Brain Project will last for ten years (2013-2023). At a cost estimated at 1.19 billion euros the HBP will become one of the most ambitious efforts in the history of science that will focus international efforts on research objectives expected to stimulate the global economy.
With three teams involved in the project, the RIKEN Brain Science Institute will contribute to the identification of the brain structures underlying mental capabilities. By listening to the brain’s activity during behavior, RIKEN investigators hope to reveal new principles of the mind and cognition. This information will guide the construction of the HBP brain model and stimulate the development of a new generation of brain-based computer and information technologies. Participating RIKEN faculty include Keiji Tanaka, Naotaka Fujii and Justin Gardner.
Dr. Naotaka Fujii’s team will contribute to the Language group by studying the neural network mechanisms of primate learning of proto-language via nested sequential stimuli. Drs Keiji Tanaka and Justin Gardner will participate in the group studying the mechanisms of information integration in the brain. The process by which semantic knowledge of the world is developed based on visual object representations and how prior knowledge of the world influences visual perception.
Charles Yokoyama, Coordinator of the RIKEN Brain Science Institute-Human Brain Project collaboration, said: “The participation of RIKEN in the Human Brain Project marks a new era in international collaboration to study the brain; such a large-scale, coordinated effort is needed to produce consistent benefits for society.”
OIST’s contribution is led by Prof. Erik De Schutter, whose team participates in the development of the Brain Simulation Platform, a major software infrastructure effort. Specifically, the team at OIST will contribute its experience in programming software for the spatial simulation of the interaction between electrophysiological events and biochemical reactions in neurons.
"We are delighted that OIST will participate in this major international initiative," said De Schutter. "Our major challenge is how to integrate fine scale of modeling at the molecular level with large-scale modeling of whole brain regions."
The project will begin work in the closing months of 2013 and will be coordinated at the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, by neuroscientist Henry Markram with co-directors Karlheinz Meier of Heidelberg University, Germany, and Richard Frackowiak of Clinique Hospitalière Universitaire Vaudoise (CHUV) and the University of Lausanne (UNIL).
Cornell Engineers Solve a Biological Mystery and Boost Artificial Intelligence
By simulating 25,000 generations of evolution within computers, Cornell University engineering and robotics researchers have discovered why biological networks tend to be organized as modules – a finding that will lead to a deeper understanding of the evolution of complexity.
The new insight also will help evolve artificial intelligence, so robot brains can acquire the grace and cunning of animals.
From brains to gene regulatory networks, many biological entities are organized into modules – dense clusters of interconnected parts within a complex network. For decades biologists have wanted to know why humans, bacteria and other organisms evolved in a modular fashion. Like engineers, nature builds things modularly by building and combining distinct parts, but that does not explain how such modularity evolved in the first place. Renowned biologists Richard Dawkins, Günter P. Wagner, and the late Stephen Jay Gould identified the question of modularity as central to the debate over “the evolution of complexity.”
For years, the prevailing assumption was simply that modules evolved because entities that were modular could respond to change more quickly, and therefore had an adaptive advantage over their non-modular competitors. But that may not be enough to explain the origin of the phenomena.
The team discovered that evolution produces modules not because they produce more adaptable designs, but because modular designs have fewer and shorter network connections, which are costly to build and maintain. As it turned out, it was enough to include a “cost of wiring” to make evolution favor modular architectures.
This theory is detailed in “The Evolutionary Origins of Modularity,” published today in the Proceedings of the Royal Society by Hod Lipson, Cornell associate professor of mechanical and aerospace engineering; Jean-Baptiste Mouret, a robotics and computer science professor at Université Pierre et Marie Curie in Paris; and by Jeff Clune, a former visiting scientist at Cornell and currently an assistant professor of computer science at the University of Wyoming.