Posts tagged neuroscience
Articles and news from the latest research reports.
Controlling Vascular Disease May Be Key to Reducing Prevalence of Alzheimer’s Disease
Over the last 15 years, researchers have found a significant association between vascular diseases such as hypertension, atherosclerosis, diabetes type 2, hyperlipidemia, and heart disease and an increased risk of Alzheimer’s disease. In a special issue of the Journal of Alzheimer’s Disease, leading experts provide a comprehensive overview of the pathological, biochemical, and physiological processes that contribute to Alzheimer’s disease risk and ways that may delay or reverse these age-related abnormalities.
“Vascular risk factors to Alzheimer’s disease offer the possibility of markedly reducing incident dementia by early identification and appropriate medical management of these likely precursors of cognitive deterioration and dementia,” says Guest Editor Jack C. de la Torre, MD, PhD, of the University of Texas, Austin. “Improved understanding coupled with preventive strategies could be a monumental step forward in reducing worldwide prevalence of Alzheimer’s disease, which is doubling every 20 years.”
The issue explores how vascular disease can affect cerebral blood flow and impair signaling, contributing to Alzheimer’s disease (AD). The diagnostics of cardiovascular risk factors in AD are addressed, as are potential therapeutic approaches.
Paradoxically, the presence of vascular risk factors in middle age is associated with the development of AD more strongly than late-life vascular disease. In fact, some research suggests that vascular symptoms later in life may have a protective effect against the development of the disease. The physiopathological mechanisms that may underlie this phenomenon are discussed.
To date, trials that target major cardiovascular risk factors in the prevention of AD remain inconclusive but have become an important focus of international research as described by contributors of this special volume in their overviews. The multifactorial nature of AD and the need to identify the proper time window for intervention when designing possible interventions, and methodological issues that will have to be addressed to achieve an optimal design of new randomized controlled trials, are discussed. Promising avenues for treatment, such as the potential of low-level light therapy to increase the rate of oxygen consumption in the brain and enhance cortical metabolic capacity, and the possibility that some antihypertensive drug classes reduce the risk and progression of AD more than others, are discussed.
Dr. de la Torre notes that the presence of vascular risk factors is not an absolute pathway to dementia, and it may be as important to study how or why individuals who are cognitively normal but have vascular risk are able to avoid dementia. “Reducing Alzheimer’s disease prevalence by focusing right now on vascular risk factors to Alzheimer’s disease, even with our limited technology, is not a simple or easy task. But the task must begin somewhere and without delay because time is running out for millions of people whose destiny with dementia may start sooner rather than later,” he concludes.
(Source: alphagalileo.org)
Amyloid-beta peptide behind Alzheimer - for the first time hydrogen bonds were analysed
Using solid-state nuclear magnetic resonance (NMR) spectroscopy, researchers at Luleå University of Technology in collaboration with Warwick University in the UK for the first time in the world managed to analyse hydrogen bonds in tiny fibrils of Amyloid-beta peptide, which probably causes Alzheimer’s disease. Thanks to these new results, there is a successful method avaliable – for analysis of structure of Amyloid-beta peptides in their most toxic form, that is, when they are most dangerous for the brain neurons.
- This is a very important step in research on Alzheimer’s disease at a molecular level, says Oleg N. Antzutkin, professor in chemistry of interfaces, at Luleå University of Technology.
Until a few years ago scientists believed that amyloid plaques in the brain directly cause Alzheimer’s disease. This is because very large amounts of plaques in the brain of Alzheimer´s patients are usually found. Since the activity of our brain is greatest in the regions responsible for short-term memory, there most of the amyloid plaques were found. Here is also usually where Alzheimer’s disease is first noticed, in the form of reduced short-term memory. However, it seems to be that Amyloid plaque are rather a residual of something worse.
Oliver Sacks has made a literary art of staring into the minds of others. So what does he make of his own?
Noam Chomsky on Where Artificial Intelligence Went Wrong
If one were to rank a list of civilization’s greatest and most elusive intellectual challenges, the problem of “decoding” ourselves — understanding the inner workings of our minds and our brains, and how the architecture of these elements is encoded in our genome — would surely be at the top. Yet the diverse fields that took on this challenge, from philosophy and psychology to computer science and neuroscience, have been fraught with disagreement about the right approach.
In 1956, the computer scientist John McCarthy coined the term “Artificial Intelligence” (AI) to describe the study of intelligence by implementing its essential features on a computer. Instantiating an intelligent system using man-made hardware, rather than our own “biological hardware” of cells and tissues, would show ultimate understanding, and have obvious practical applications in the creation of intelligent devices or even robots.
Some of McCarthy’s colleagues in neighboring departments, however, were more interested in how intelligence is implemented in humans (and other animals) first. Noam Chomsky and others worked on what became cognitive science, a field aimed at uncovering the mental representations and rules that underlie our perceptual and cognitive abilities. Chomsky and his colleagues had to overthrow the then-dominant paradigm of behaviorism, championed by Harvard psychologist B.F. Skinner, where animal behavior was reduced to a simple set of associations between an action and its subsequent reward or punishment. The undoing of Skinner’s grip on psychology is commonly marked by Chomsky’s 1967 critical review of Skinner’s bookVerbal Behavior, a book in which Skinner attempted to explain linguistic ability using behaviorist principles.
The idea of an untethered consciousness is something we can understand, even when we don’t suppose it is found in nature.
Why Children Think They Are Invisible when Covering Their Eyes
Dr. James Russell and a research team at the University of Cambridge recently published work on young children’s conception of personal visibility, which furthers the understanding of cognitive development and of our emerging sense of self.
The research involved children three to four years of age. Researchers placed an eye mask on each of the children and asked them if they could be seen when wearing it. They then asked each child if an adult who was wearing a similar mask could be seen. The majority of the children involved in the study believed they were not visible when wearing the mask. Most also believed that the adult wearing the eye mask was also hidden.
Additional tests revealed a unique layer of complexity, demonstrating that although the children thought they were invisible when there eyes were covered, they still believed that their head and body were able to be seen.
The research team concluded by process of elimination that the factor that makes children believe they are visible is eye contact with another person.
“… it would seem that children apply the principle of joint attention to the self and assume that for somebody to be perceived, experience must be shared and mutually known to be shared, as it is when two pairs of eyes meet,” the researchers reported. “Young children’s natural tendency to acquire knowledge intersubjectively, by joint attention, leads them to undergo a developmental period in which they believe the self is something that must be mutually experienced for it to be perceived.”
Evidently, children only believe they exist when making eye contact with another person. The implications point to a simple but necessary way to make children feel present and involved. Cultures worldwide seem to have some version of “peek-a-boo,” as a quick Google image search reveals. Lack of eye contact in children has been linked as an early sign of autism, while the presence of eye contact is associated with empathy. Dr. Russell’s team seems to have discovered a key facet of cognitive development.
The results of Dr. Russell’s study were published in the Journal of Cognition and Development.
(Source: united-academics.org)
OneZoom: A Fractal Explorer for the Tree of Life
Our knowledge of the tree of life—a phylogenetic tree summarizing the evolutionary relationships among all life on Earth—is expanding rapidly. “Mega-trees” with millions of tips (species) are expected to appear imminently (for example, see http://www.opentree.wikispaces.com). Unfortunately, there has so far been no practical and intuitive way to explore even the much smaller trees with thousands of tips that are now being routinely produced. Without a way to view megatrees, these wondrous objects, representing the culmination of decades of scientific effort, cannot be fully appreciated. The field really needs a solution to this problem to enable scientists to communicate important evolutionary concepts and data effectively, both to each other and to the general public.
Just like Google Earth changed the way people look at geography, a sophisticated tree of life browser could really change the way we look at the life around us … Our advances in understanding evolution are moving really fast now, but the tools for looking at these big trees are lagging behind. (Westneat, February 2009)
Displaying large trees is a hard problem that has so far resisted solution. We are still waiting for the equivalent of a Google Maps. (Page, June 2012)
In this manuscript, we introduce a new approach that solves the problem. Trees with millions of tips, richly embellished with additional data, can now be easily explored within the web browser of any modern hardware with a zooming user interface similar to that used in Google Maps.
Multivitamin lifts brain activity
A daily multivitamin supplement may improve brain efficiency in older women, according to new research from Swinburne University of Technology.
Centre for Human Psychopharmacology researcher at Swinburne, Dr Helen Macpherson’s four month study of the commercial product Swisse Women’s Ultivite 50+ found some evidence that multivitamin supplements may influence cognitive function by altering electrical activity in the brain.
"The main finding of the study was that 16 weeks supplementation with the Swisse Women’s 50+ multivitamin modulated brain activity," Dr Macpherson said.
"This is an important result as it shows there are direct effects of multivitamins on the brain.
"Previous research has used measures of behaviour to determine whether multivitamins can affect brain function, but this is the first trial to directly measure brain activity."
The study was conducted over 16 weeks with 56 women aged between 64 and 79 who were concerned about their memory or experiencing memory difficulties. They were randomly assigned to take the multivitamin supplement or a placebo daily.
Volunteers underwent a recording of their brain electrical activity whilst performing a spatial working memory task.
The research was published in Physiology and Behavior.
A previous paper published in Psychopharmacology reported that multivitamin supplementation improved behavioural performance on a similar task, in the same group of participants.
The study concluded that 16 weeks of supplementation with a combined multivitamin, mineral and herbal formula may benefit memory, by enabling the brain to work in a more efficient way.
"When considered with our other findings of benefits to memory performance, there is increasing evidence that multivitamins may be useful to combat cognitive decline in the elderly," Dr Macpherson said.
(Source: swinburne.edu.au)
Brain imaging alone cannot diagnose autism
In a column appearing in the current issue of the journal Nature, McLean Hospital biostatistician Nicholas Lange, ScD, cautions against heralding the use of brain imaging scans to diagnose autism and urges greater focus on conducting large, long-term multicenter studies to identify the biological basis of the disorder.
"Several studies in the past two years have claimed that brain scans can diagnose autism, but this assertion is deeply flawed," said Lange, an associate professor of Psychiatry and Biostatistics at Harvard Medical School. "To diagnose autism reliably, we need to better understand what goes awry in people with the disorder. Until its solid biological basis is found, any attempt to use brain imaging to diagnose autism will be futile."
While cautioning against current use of brain imaging as a diagnostic tool, he is a strong proponent of using this technology to help scientists better understand autism. Through the use of various brain imaging techniques, including functional magnetic resonance imaging (MRI), positron emission tomography (PET), and volumetric MRI, Lange points out that researchers have made important discoveries related to early brain enlargement in the disorder, how those with autism focus during social interaction and the role of serotonin in someone with autism.
"Brain scans have led to these extremely valuable advances, and, with each discovery, we are getting closer to solving the autism pathology puzzle," said Lange. "What individuals with autism and their parents urgently need is for us to carry out large-scale studies that lead us to find reliable, sensitive and specific biological markers of autism with high predictive value that allow clinicians to identify interventions that will improve the lives of people with the disorder."
Autism and autism spectrum disorder (ASD) are terms regularly used to describe a group of complex disorders of brain development. This spectrum characterized, in varying degrees, by difficulties in social interaction, verbal and nonverbal communication, and repetitive behaviors, whose criteria have been revised in the newly proposed Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The prevalence of ASD in the United States has increased 78 percent in the last decade, with the Centers for Disease Control estimating that one in 88 children has ASD.
(Source: eurekalert.org)