Posts tagged science
Articles and news from the latest research reports.
Double Duty: Immune System Regulator Found to Protect Brain from Effects of Stroke
A small molecule known to regulate white blood cells has a surprising second role in protecting brain cells from the deleterious effects of stroke, Johns Hopkins researchers report. The molecule, microRNA-223, affects how cells respond to the temporary loss of blood supply brought on by stroke — and thus the cells’ likelihood of suffering permanent damage.
“We set out to find a small molecule with very specific effects in the brain, one that could be the target of a future stroke treatment,” says Valina Dawson, Ph.D., a professor in the Johns Hopkins University School of Medicine’s Institute for Cell Engineering. “What we found is this molecule involved in immune response, which also acts in complex ways on the brain. This opens up a suite of interesting questions about what microRNA-223 is doing and how, but it also presents a challenge to any therapeutic application.” A report on the discovery is published in the Nov. 13 issue of the Proceedings of the National Academy of Sciences.
RNA is best known as a go-between that shuttles genetic information from DNA and then helps produce proteins based on that information. But, Dawson explains, a decade ago researchers unearthed a completely different class of RNA: small, nimble fragments that regulate protein production. In the case of microRNA, one member of this class, that control comes from the ability to bind to RNA messenger molecules carrying genetic information, and thus prevent them from delivering their messages. “Compared with most ways of shutting genes off, this one is very quick,” Dawson notes.
Reasoning that this quick action, along with other properties, could make microRNAs a good target for therapy development, Dawson and her team searched for microRNAs that regulate brain cells’ response to oxygen deprivation.
To do that, they looked for proteins that increased in number in cells subjected to stress, and then examined how production of these proteins was regulated. For many of them, microRNA-223 played a role, Dawson says.
In most cases, the proteins regulated by microRNA-223 turned out to be involved in detecting and responding to glutamate, a common chemical signal brain cells use to communicate with each other. A stroke or other injury can lead to a dangerous excess of glutamate in the brain, as can a range of diseases, including autism and Alzheimer’s.
Because microRNA-223 is involved in regulating so many different proteins, and because it affects glutamate receptors, which themselves are involved in many different processes, the molecule’s reach turned out to be much broader than expected, says Maged M. Harraz, Ph.D., a research associate at Hopkins who led the study. “Before this experiment, we didn’t appreciate that a single microRNA could regulate so many proteins,” he explains.
This finding suggests that microRNA-223 is unlikely to become a therapeutic target in the near future unless researchers figure out how to avoid unwanted side effects, Dawson says.
(Source: hopkinsmedicine.org)
Brain cell transplants in early 2013
As part of the European study TRANSEURO, five patients with Parkinson’s disease will undergo brain cell transplants at Skåne University Hospital in Lund, Sweden, in early 2013. These are the first operations of their kind in Europe for over 10 years.
The TRANSEURO study, which in Sweden is led by Lund University, is now taking a critical approach to the viability of cell therapy as a future treatment for Parkinson’s disease. Can we replace cells that die as a result of our most common neurological diseases? What are the therapies of the future for neurodegenerative diseases like Parkinson’s and Alzheimer’s?
Under the leadership of Professor of Neurology Olle Lindvall, brain researchers in Lund had already developed a method of transplanting nerve cells in the 1980s. In 1987, brain surgeon Stig Rehncrona operated on the very first patient. That study was historic and marked the first repair of the human nervous system. The news was cabled out to all the world’s media and the Swedish researchers soon graced the front page of the New York Times.
"Since the advances made in the 1980s and 1990s, the research field has encountered many obstacles. In the early 2000s, two American studies produced negative results, which meant that cell transplants for Parkinson’s disease came to a dead end," says Professor Anders Björklund, who in the 1980s was responsible for the ground-breaking discoveries in the laboratory.
Despite the unsatisfactory results presented in the American trials, cell therapy has still been seen to have effects that are entirely unique in the history of research on Parkinson’s. A third of the transplant patients have seen significant benefits of cell therapy over a very long period without medication, in some cases up to 20 years.
"For a disease with a very demanding medication regime, and for which the effects of the standard medication begin to diminish after 5 years, cell therapy represents a hope of a different life for many Parkinson’s sufferers", says Professor Håkan Widner, who is in charge of patient recruitment in Lund.
"The results of TRANSEURO will play an important role in the immediate future of cell therapy as a viable treatment. We have scrutinized the failed American studies in an attempt to optimise the technique, improve patient selection and conduct more personalised follow-up. We are hopeful that the results will be different this time", says Professor Widner.
(Source: machineslikeus.com)
Mediation Combined with Art Therapy Can Change Your Brain and Lower Anxiety
Cancer and stress go hand-in-hand, and high stress levels can lead to poorer health outcomes in cancer patients. The Jefferson-Myrna Brind Center of Integrative Medicine combined creative art therapy with a Mindfulness-based Stress Reduction (MBSR) program for women with breast cancer and showed changes in brain activity associated with lower stress and anxiety after the eight-week program. Their new study appears in the December issue of the journal Stress and Health.
Daniel Monti, MD, director of the Jefferson-Myrna Brind Center of Integrative Medicine and lead author on the study, and colleagues have previously published on the success of Mindfulness-based Art Therapy (MBAT) at helping cancer patients lower stress levels and improve quality of life.
“Our goal was to observe possible mechanisms for the observed psychosocial effects of MBAT by evaluating the cerebral blood flow (CBF) changes associated with an MBAT intervention in comparison with a control of equal time and attention,” says Monti. “This type of expressive art and meditation program has never before been studied for physiological impact and the correlation of that impact to improvements in stress and anxiety.”
Drug May Offer New Approach to Treating Insomnia
A new drug may bring help for people with insomnia, according to a study published in the November 28, 2012, online issue of Neurology®, the medical journal of the American Academy of Neurology.
The drug, suvorexant, blocks the chemical messengers in the brain called orexins, which regulate wakefulness. Other drugs for insomnia affect different brain receptors.
Taking the drug suvorexant increased the amount of time people spent asleep during the night, according to the study. The study involved 254 people ages 18 to 64 who were in good physical and mental health but had insomnia that was not due to another medical condition.
The participants took either the drug or a placebo for four weeks, then switched to the other treatment for another four weeks. The participants spent the night in a sleep laboratory with their sleep monitored on the first night with each treatment and then again in the fourth week of each treatment.
While taking the drug, participants’ “sleep efficiency,” which reflects the total amount of time they slept during a fixed, eight hour time in bed, improved by 5 to 13 percent compared to those taking the placebo. They also experienced 21 to 37 fewer minutes awake during the night after they had fallen asleep than those who took the placebo. “This study provides evidence that suvorexant may offer a successful alternative strategy for treating insomnia,” said study author W. Joseph Herring, MD, PhD, of North Wales, Penn., Executive Director of Clinical Research with Merck, the maker of suvorexant, and a member of the American Academy of Neurology. “Suvorexant was generally well-tolerated, and there were no serious side effects.”
Herring said larger, longer studies have recently been conducted on suvorexant, along with studies to determine whether the drug could be safe and effective for elderly people, who make up a large percentage of those suffering from insomnia.
Thought-controlled prosthesis is changing the lives of amputees
The world’s first implantable robotic arm controlled by thoughts is being developed by Chalmers researcher Max Ortiz Catalan. The first operations on patients will take place this winter.
“Our technology helps amputees to control an artificial limb, in much the same way as their own biological hand or arm, via the person’s own nerves and remaining muscles. This is a huge benefit for both the individual and to society”, says Max Ortiz Catalan, industrial doctoral student at Chalmers University of Technology in Sweden.
Ever since the 1960s, amputees have been able to use prostheses controlled by electrical impulses in the muscles. Unfortunately, however, the technology for controlling these prostheses has not evolved to any great extent since then. For example, very advanced electric hand prostheses are available, but their functionality is limited because they are difficult to control.
“All movements must by pre-programmed”, says Max Ortiz Catalan. “It’s like having a Ferrari without a steering wheel. Therefore, we have developed a new bidirectional interface with the human body, together with a natural and intuitive control system.”
Today’s standard socket prostheses, which are attached to the body using a socket tightly fitted on the amputated stump, are so uncomfortable and limiting that only 50 percent of arm amputees are willing to use one at all.
This research project is using the world-famous Brånemark titanium implant instead (OPRA Implant System), which anchors the prosthesis directly to the skeleton through what is known as osseointegration.“Osseointegration is vital to our success. We are now using the technology to gain permanent access to the electrodes that we will attach directly to nerves and muscles”, says Max Ortiz Catalan.
The placebo effect goes beyond humans
Rats and humans have at least one thing in common: They both react the same way to a placebo, according to a new University of Florida study.
“That was the big finding — that the animals that expected pain relief actually got pain relief when you gave them an inert substance,” said co-author John Neubert, a pain specialist and an associate professor with the UF College of Dentistry department of orthodontics. “It helps validate our model that what we do in the rats, we believe, is a good representation of what’s being seen in humans.”
The investigation of placebo effects might lead to the identification of new therapeutic targets in the brain and of novel treatment strategies for a variety of health conditions.
A placebo response is a response seemingly to a treatment that has not actually been administered. For this study researchers looked at placebo responses in reference to pain and pain relief by evaluating how an animal responds when it “thinks” it’s getting a pain reliever.
UF researchers conditioned rats to expect morphine or salt water by giving injections of one or the other for two sessions. Then during the third session, researchers gave both groups the saline injection. About 30 to 40 percent of the group that had previously received morphine acted as if they had received morphine again and showed pain relief.
“What that means is we can then go ahead and do more mechanistic studies and do pharmacological studies targeting different receptors,” he said. “We could do different procedures and try to apply that knowledge into what we think is going on in humans.”
The two-year study published in the journal PAIN in October was the result of collaboration between Neubert and Niall Murphy, an addiction specialist and adjunct associate professor at the University of California Los Angeles. The two decided to look at placebo responses because that deals with pathways and mechanisms that relate to pain, reward and addiction.
According to psychological lore, when it comes to items of information the mind can cope with before confusion sets in, the “magic” number is seven. But a new analysis by a leading Australian psychiatrist challenges this long-held view, suggesting the number might actually be four.
In 1956, American psychologist George Miller published a paper in the influential journal Psychological Review arguing the mind could cope with a maximum of only seven chunks of information. The paper, “The Magical Number Seven, Plus or Minus Two. Some Limits on Our Capacity for Processing Information”, has since become one of the most highly cited psychology articles and has been judged by the Psychological Review as its most influential paper of all time.
But UNSW professor of psychiatry Gordon Parker says a re-analysis of the experiments used by Miller shows he missed the correct number by a wide mark. Writing in the journal Acta Psychiatrica Scandinavica, Scientia Professor Parker says a closer look at the evidence shows the human mind copes with a maximum of four ‘chunks’ of information, not seven.
“So to remember a seven numeral phone number, say 6458937, we need to break it into four chunks: 64. 58. 93. 7. Basically four is the limit to our perception.
“That’s a big difference for a paper that is one of the most highly referenced psychology articles ever – nearly a 100 percent discrepancy,” he suggests.
Professor Parker says the success of the original paper lies “more in its multilayered title and Miller’s evocative use of the word ‘magic’,” than in the science.
Professor Parker says 50 years after Miller there is still uncertainty about the nature of the brain’s storage capacity limits: “There may be no limit in storage capacity per se but only a limit to the duration in which items can remain active in short-term memory”. “Regardless, the consensus now is that humans can best store only four chunks in short-term memory tasks,” he says.
Moral evaluations of harm are instant and emotional
People are able to detect, within a split second, if a hurtful action they are witnessing is intentional or accidental, new research on the brain at the University of Chicago shows.
The study is the first to explain how the brain is hard-wired to recognize when another person is being intentionally harmed. It also provides new insights into how such recognition is connected with emotion and morality, said lead author Jean Decety, the Irving B. Harris Professor of Psychology and Psychiatry at UChicago.
“Our data strongly support the notion that determining intentionality is the first step in moral computations,” said Decety, who conducted research on the topic with Stephanie Cacioppo, a research associate (assistant professor) in psychology at UChicago. They published the results in a paper, “The Speed of Morality: A High-Density Electrical Neurological Study,” to be published Dec. 1 and now on early preview in the Journal of Neurophysiology.
The researchers studied adults who watched videos of people who suffered accidental harm (such as being hit with a golf club) and intentional harm (such as being struck with a baseball bat). While watching the videos, brain activity was collected with equipment that accurately maps responses in different regions of the brain and importantly, the timing between these regions. The technique is known as high-density, event-related potentials technology.
The intentional harm sequence produced a response in the brain almost instantly. The study showed that within 60 milliseconds, the right posterior superior temporal sulcus (also known as TPJ area), located in the back of the brain, was first activated, with different activity depending on whether the harm was intentional or accidental. It was followed in quick succession by the amygdala, often linked with emotion, and the ventromedial prefrontal cortex (180 milliseconds), the portion of the brain that plays a critical role in moral decision-making.
There was no such response in the amygdala and ventromedial prefrontal cortex when the harm was accidental.
New Studies Show Moral Judgments Quicker, More Extreme than Practical Ones—But Also Flexible
Judgments we make with a moral underpinning are made more quickly and are more extreme than those same judgments based on practical considerations, a new set of studies finds. However, the findings, which appear in the journal PLOS ONE, also show that judgments based on morality can be readily shifted and made with other considerations in mind.
“Little work has been done on how attaching morality to a particular judgment or decision may affect that outcome,” explains Jay Van Bavel, an assistant professor in New York University’s Department of Psychology and one of the study’s co-authors. “Our findings show that we make and see decisions quite differently if they are made with a morality frame. But, despite these differences, there is now evidence that we can shift judgments so they are based on practical, rather than moral, considerations—and vice versa.”
“Our findings suggest that deciding to frame any issue as moral or not may have important consequences,” said co-author Ingrid Haas, an assistant professor of political science at the University of Nebraska-Lincoln. “Once an issue is declared moral, people’s judgments about that issue become more extreme, and they are more likely to apply those judgments to others.”
“Ultimately, the way that people make decisions is likely to affect their behavior,” said co-author Dominic Packer, an assistant professor at Lehigh University. ”People may act in ways that violate their moral values when they make decisions in terms of pragmatic concerns - dollars and cents - rather than in a moral frame. In ongoing research, we are examining factors that can trigger moral forms of decision making, so that people are more likely to behave in line with their values.”