Researchers have long known that individual diseases are associated with genes in specific locations of the genome

Genetics researchers at the University of North Carolina at Chapel Hill now have shown definitively that a small number of places in the human genome are associated with a large number and variety of diseases. In particular, several diseases of aging are associated with a locus which is more famous for its role in preventing cancer.

For this analysis, researchers at UNC Lineberger Comprehensive Cancer Center catalogued results from several hundred human Genome-Wide Association Studies (GWAS) from the National Human Genome Research Institute. These results provided an unbiased means to determine if varied different diseases mapped to common ‘hotspot’ regions of the human genome. This analysis showed that two different genomic locations are associated with two major subcategories of human disease.

“Our team is interested in understanding genetic susceptibility to diseases associated with aging, including cancer,” said PhD student William Jeck, who was first author on the study, published in the journal Aging Cell.

Dyslexia Impairs Speech Recognition but Can Spare Phonological Competence

Dyslexia is associated with numerous deficits to speech processing. Accordingly, a large literature asserts that dyslexics manifest a phonological deficit. Few studies, however, have assessed the phonological grammar of dyslexics, and none has distinguished a phonological deficit from a phonetic impairment. Here, we show that these two sources can be dissociated. Three experiments demonstrate that a group of adult dyslexics studied here is impaired in phonetic discrimination (e.g., ba vs. pa), and their deficit compromises even the basic ability to identify acoustic stimuli as human speech. Remarkably, the ability of these individuals to generalize grammatical phonological rules is intact. Like typical readers, these Hebrew-speaking dyslexics identified ill-formed AAB stems (e.g., titug) as less wordlike than well-formed ABB controls (e.g., gitut), and both groups automatically extended this rule to nonspeech stimuli, irrespective of reading ability. The contrast between the phonetic and phonological capacities of these individuals demonstrates that the algebraic engine that generates phonological patterns is distinct from the phonetic interface that implements them. While dyslexia compromises the phonetic system, certain core aspects of the phonological grammar can be spared.

A new guideline released by the American Academy of Neurology may help doctors in making the diagnosis of Creutzfeldt-Jakob disease. The guideline is published in the September 19, 2012, online issue of Neurology®, the medical journal of the American Academy of Neurology.

Creutzfeldt-Jakob disease is a rare, always fatal brain disorder that involves quickly progressing dementia. New cases appear in about one person per million each year worldwide and confirming the diagnosis is challenging. People with the disease can have a wide range of symptoms. Many other conditions can cause similar symptoms, and with some of these conditions the dementia can be treated.

The guideline focused only on the diagnosis of sporadic Creutzfeldt-Jakob disease.

Neuroscientists Investigate Lotteries to Study How the Brain Evaluates Risk

People are faced with thousands of choices every day, some inane and some risky. Scientists know that the areas of the brain that evaluate risk are the same for each person, but what makes the value assigned to risk different for individuals?

To answer this question, a new video article in Journal of Visualized Experiments (JoVE) uses functional magnetic resonance imaging (fMRI) to characterize subjective risk assessment while subjects choose between different lotteries to play.

The article, a joint effort from laboratories at Yale School of Medicine and New York University, is led by Yale’s Dr. Ifat Levy. Dr. Levy explains, “This procedure allows us to examine all kinds of normal and pathological behaviors focusing on risk assessment. It could explain things like substance abuse and over-eating from a different perspective than how it is usually characterized.”

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.

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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.”

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.