Could PTSD involve immune cell response to stress? Study in mice raises question

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Chronic stress that produces inflammation and anxiety in mice appears to prime their immune systems for a prolonged fight, causing the animals to have an excessive reaction to a single acute stressor weeks later, new research suggests.After the mice recovered from the effects of chronic stress, a single stressful event 24 days later quickly returned them to a chronically stressed state in biological and behavioral terms. Mice that had not experienced the chronic stress were unaffected by the single acute stressor.The study further showed that immune cells called to action as a result of chronic stress ended up on standby in the animals’ spleens and were launched from that organ to respond to the later stressor.Mice without spleens did not experience the same reactivation with the second stressor, signifying the spleen’s role as a reservoir for primed immune cells to remain until they’re activated in response to another stressor.The excessive immune response and anxiety initiated by a brief stressor mimic symptoms of post-traumatic stress disorder.The Ohio State University scientists are cautious about extending their findings to humans. But they say their decade of work with this model of stress suggests that the immune system has a significant role in affecting behavior. And they are the first to study this re-establishment of anxiety in animals with a later acute stressor.“No one else has done a study of this length to see what happens to recovered animals if we subject them again to stress,” said Jonathan Godbout, a lead author of the study and associate professor of neuroscience at Ohio State. “That retriggering is a component of post-traumatic stress. The previously stressed mice are living a normal rodent life, and then this acute stress brings everything back. Animals that have never been exposed to stress before were unaffected by that one event – it didn’t change behavioral or physiological properties.”The research is published online in the journal Biological Psychiatry.These scientists previously determined that in mice with chronic stress, cells from the immune system were recruited to the brain and promoted symptoms of anxiety. The findings identified a subset of immune cells, called monocytes, that could be targeted by drugs for treatment of mood disorders – including, potentially, the recurrent anxiety initiated by stress that is a characteristic of PTSD.The research reveals new ways of thinking about the cellular mechanisms behind the effects of stress, identifying two-way communication from the central nervous system to the periphery – the rest of the body – and back to the central nervous system that ultimately influences behavior.“We haven’t proffered that there is a cellular component to PTSD, but there very well might be. And it’s very possible that it sits in the periphery as we’ve been describing in the mouse,” said John Sheridan, senior author of the study, professor of oral biology and associate director of Ohio State’s Institute for Behavioral Medicine Research.In this model of stress, male mice living together are given time to establish a hierarchy, and then an aggressive male is added to the group for two hours at a time. The resident mice are repeatedly defeated, and this social defeat over six days leads to an inflammatory immune response and anxiety-like behavior.This kind of stress triggers the sympathetic nervous system and a commonly known fight-or-flight response. …


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It’s alive! Bacteria-filled liquid crystals could improve biosensing

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Plop living, swimming bacteria into a novel water-based, nontoxic liquid crystal and a new physics takes over. The dynamic interaction of the bacteria with the liquid crystal creates a novel form of soft matter: living liquid crystal.The new type of active material, which holds promise for improving the early detection of diseases, was developed by a research collaboration based at Ohio’s Kent State University and Illinois’ Argonne National Laboratory. The team will present their work at the 58th annual Biophysical Society Meeting, held in San Francisco, Feb.15-19.As a biomechanical hybrid, living liquid crystal moves and reshapes itself in response to external stimuli. It also stores energy just as living organisms do to drive its internal motion. And it possesses highly desirable optical properties. In a living liquid crystal system, with the aid of a simple polarizing microscope, you can see with unusual clarity the wake-like trail stimulated by the rotation of bacterial flagella just 24-nanometers thick, about 1/4000th the thickness of an average human hair.You can also control and guide active movements of the bacteria by manipulating variables such as oxygen availability, temperature or surface alignment, thus introducing a new design concept for creating microfluidic biological sensors. Living liquid crystal provides a medium to amplify tiny reactions that occur at the micro- and nano-scales — where molecules and viruses interact — and to also easily optically detect and analyze these reactions. That suits living liquid crystal to making sensing devices that monitor biological processes such as cancer growth, or infection. Such microfluidic technology is of increasing importance to biomedical sensing as a means of detecting disease in its earliest stages when it is most treatable, and most cost-effectively managed.”As far as we know, these things have never been done systematically as we did before in experimental physics,” explained Shuang Zhou, a Ph.D. candidate at Ohio’s Kent State University. …


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Elevated brain aluminium, early onset Alzheimer"s disease in an individual occupationally exposed to aluminium

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Research at Keele University in Staffordshire, UK, has shown for the first time that an individual who was exposed to aluminum at work and died of Alzheimer’s disease had high levels of aluminum in the brain.While aluminum is a known neurotoxin and occupational exposure to aluminum has been implicated in neurological disease, including Alzheimer’s disease, this finding is believed to be the first record of a direct link between Alzheimer’s disease and elevated brain aluminum following occupational exposure to the metal.In 2003 a 58-year-old Caucasian male with no previous medical history of note was diagnosed with Alzheimer’s disease. Ten years previous to this the man, from the north-east of England, began to work with the preparation of a novel material (DARMATT KM1) used as insulation in the nuclear fuel and space industries. This work exposed him to aluminum sulphate ‘dust’ on a daily basis over 8 years. An ‘ordinary’ dust mask was supplied to protect against inhalation of the materials. Within a short time of starting this work the man complained of headaches, tiredness and mouth ulcers. By 1999 he started to show problems in relation to memory and suffered depression.Following his death, aged 66, in 2011, a neuropathological examination confirmed advance stage Alzheimer’s disease. There then followed the most comprehensive investigation ever of the aluminum content of the frontal lobe of a single individual with 49 different tissue samples being measured for aluminum.Professor Chris Exley, of The Birchall Centre, at Keele University, said: “The results showed unequivocally that the frontal lobe contained an average aluminum content which was at least four times higher than might be expected for an age-matched control brain.”The observation that air-borne aluminum dust was most likely responsible for the elevated levels of aluminum in the brain must then heavily implicate the nose and possibly the lungs as the main routes of entry of aluminum into the body and the brain.”Overall, these results suggest very strongly that occupational exposure to aluminum contributed significantly to the untimely death of this individual with Alzheimer’s disease.”Story Source:The above story is based on materials provided by Keele University. Note: Materials may be edited for content and length.


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Psychologist shows why talking to kids really matters

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Fifty years of research has revealed the sad truth that the children of lower-income, less-educated parents typically enter school with poorer language skills than their more privileged counterparts. By some measures, 5-year-old children of lower socioeconomic status (SES) score two years behind on standardized language development tests by the time they enter school.In recent years, Anne Fernald, a psychology professor at Stanford University, has conducted experiments revealing that the language gap between rich and poor children emerges during infancy. Her work has shown that significant differences in both vocabulary and real-time language processing efficiency were already evident at age 18 months in English-learning infants from higher- and lower-SES families. By age 24 months, there was a six-month gap between SES groups in processing skills critical to language development.Fernald’s work has also identified one likely cause for this gap. Using special technology to make all-day recordings of low-SES Spanish-learning children in their home environments, Fernald and her colleagues found striking variability in how much parents talked to their children. Infants who heard more child-directed speech developed greater efficiency in language processing and learned new words more quickly. The results indicate that exposure to child-directed speech — as opposed to overheard speech — sharpens infants’ language processing skills, with cascading benefits for vocabulary learning.Fernald and colleagues are now running a parent-education intervention study with low-income Spanish-speaking mothers in East San Jose, California, funded by the W. K. Kellogg Foundation. This new program, called Habla conmigo! …


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The physics of curly hair

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The heroes and villains in animated films tend to be on opposite ends of the moral spectrum. But they’re often similar in their hair, which is usually extremely rigid or — if it moves at all — is straight and swings to and fro. It’s rare to see an animated character with bouncy, curly hair, since computer animators don’t have a simple mathematical means for describing it.However, change may be coming soon to a theater near you: In a paper appearing in the Feb. 13 issue of Physical Review Letters, researchers at MIT and the Universit Pierre et Marie Curie in Paris provide the first detailed model for the 3-D shape of a strand of curly hair.This work could have applications in the computer animation film industry, but it also could be used by engineers to predict the curve that long steel pipes, tubing, and cable develop after being coiled around a spool for transport. In the field, these materials often act like a stubborn garden hose whose intrinsic curves make it behave in unpredictable ways. In engineering terminology, these items — and hair — are all examples of a slender, flexible rod.Co-authors on the paper are Pedro Reis, an assistant professor in MIT’s Department of Civil and Environmental Engineering and Department of Mechanical Engineering; Basile Audoly and Arnaud Lazarus, of the Universit Pierre et Marie Curie; and former MIT graduate student James Miller, who is now a research associate at Schlumberger-Doll Research. Miller worked on this project as part of his doctoral thesis research and is lead author of the paper.”Our work doesn’t deal with the collisions of all the hairs on a head, which is a very important effect for animators to control a hairstyle,” Reis says. “But it characterizes all the different degrees of curliness of a hair and describes mathematically how the properties of the curl change along the arc length of a hair.”When Reis set out to investigate the natural curvature in flexible rods, he wasn’t thinking of hair. But as he studied several small flexible, curved segments of tubing suspended from a structure in his lab, he realized they weren’t so different from strands of curly hair hanging on a head. That’s when he contacted Audoly, who had previously developed a theory to explain the 2-D shape of human hair.Using lab experimentation, computer simulation, and theory — “the perfect triangle of science,” Reis says — the team identified the main parameters for curly hair and simplified them into two dimensionless parameters for curvature (relating to the ratio of curvature and length) and weight (relating to the ratio of weight and stiffness). …


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Abolition of fixed retirement age called for by new UK report

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A report led by a professor at the University of Southampton recommends the worldwide removal of the fixed or default retirement age (DRA). Professor Yehuda Baruch from the Southampton Management School, in collaboration with Dr Susan Sayce from the University of East Anglia and Professor Andros Gregoriou from the University of Hull, has found that, on a global scale, current pension systems are unsustainable.Professor Baruch comments: “We have a global problem with funding pensions, which assume people will retire around their mid-60s. Young people are tending to start work later and in-turn start paying tax and pension contributions later. Older people are living longer, often in to their 90s, creating, in some cases, up to 30 years of retirement to provide for with their cover. This creates a funding gap.”Our study advocates the abolition of the default retirement age worldwide by governments and private companies — allowing people to consider a range of options on how and when to stop work, as well as greater flexibility over their pension plans. This would help ease funding problems.”The UK abolished the default retirement age in 2011, although a small number of organizations can fix their own DRA if they can justify reasons for doing so. However, other countries still have fixed retirement ages. The report authors have used the UK as a case study to examine the benefits and pitfalls of a more flexible approach to retirement.The researchers conducted financial analysis based on Monte Carlo simulation methodology to interrogate pension and other financial data. Their results suggest that where DRA is in place the pensions system is not sustainable in the long-run and recommend ending its use in other countries, in line with the UK approach.Professor Baruch says: “We would like to see a situation where people globally can be much more in control of when they retire. For example, they may want to work into their 70s or even 80s, but perhaps want to change the type or volume of work they take on.”Our study suggests that old age can be seen as holding the prospect of long-term stable contributions to society, rather than a decline or preparation for giving up work altogether — which can lead to pressure on the public purse.”The researchers conclude that if the default retirement age is to be successfully abolished worldwide, there needs to be a shift in cultural attitudes towards older workers and the perception of their value and productivity — as well as a change in the labour market to help older workers step into jobs, as well as out of jobs. …


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