Posts tagged science
Articles and news from the latest research reports.
Social bee-haviour: The secret life of the hive
The extraordinary mental feats of bees are forcing us to rethink what we thought we knew about intelligence. Prepare to be surprised at what a tiny brain can do as we take a look at some of what these industrious honey-makers get up to.
Origin of intelligence and mental illness linked to ancient genetic accident
Scientists have discovered for the first time how humans – and other mammals – have evolved to have intelligence. Researchers have identified the moment in history when the genes that enabled us to think and reason evolved.
This point 500 million years ago provided our ability to learn complex skills, analyse situations and have flexibility in the way in which we think. Professor Seth Grant, of the University of Edinburgh, who led the research, said: “One of the greatest scientific problems is to explain how intelligence and complex behaviours arose during evolution.”
The research, which is detailed in two papers in Nature Neuroscience, also shows a direct link between the evolution of behaviour and the origins of brain diseases. Scientists believe that the same genes that improved our mental capacity are also responsible for a number of brain disorders.
"This ground breaking work has implications for how we understand the emergence of psychiatric disorders and will offer new avenues for the development of new treatments," said John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, one of the study funders.
The study shows that intelligence in humans developed as the result of an increase in the number of brain genes in our evolutionary ancestors. The researchers suggest that a simple invertebrate animal living in the sea 500 million years ago experienced a ‘genetic accident’, which resulted in extra copies of these genes being made.
This animal’s descendants benefited from these extra genes, leading to behaviourally sophisticated vertebrates – including humans. The research team studied the mental abilities of mice and humans, using comparative tasks that involved identifying objects on touch-screen computers.
Researchers then combined results of these behavioural tests with information from the genetic codes of various species to work out when different behaviours evolved. They found that higher mental functions in humans and mice were controlled by the same genes.
Childhood trauma leaves mark on DNA of some victims
Abused children are at high risk of anxiety and mood disorders, as traumatic experience induces lasting changes to their gene regulation. Scientists from the Max Planck Institute of Psychiatry in Munich have now documented for the first time that genetic variants of the FKBP5 gene can influence epigenetic alterations in this gene induced by early trauma. In individuals with a genetic predisposition, trauma causes long-term changes in DNA methylation leading to a lasting dysregulation of the stress hormone system. As a result, those affected find themselves less able to cope with stressful situations throughout their lives, frequently leading to depression, post-traumatic stress disorder or anxiety disorders in adulthood. Doctors and scientists hope these discoveries will yield new treatment strategies tailored to individual patients, as well as increased public awareness of the importance of protecting children from trauma and its consequences.
The Brain: The Charlie Brown Effect
I am sitting in a darkened, closet-size lab at Tufts University, my scalp covered by a blue cloth cap studded with electrodes that detect electric signals from my brain. Data flow from the electrodes down rainbow-colored wires to an electroencephalography (eeg) machine, which records the activity so a scientist can study it later on.
Wearing this elaborate setup, I gaze at a television in front of me, focusing on a tiny cross at the center of the screen. The cross disappears, and a still image appears of Snoopy chasing a leaf. Then Charlie Brown takes Snoopy’s place, pitching a baseball. Lucy, Linus, and Woodstock visit as well. For the next half hour I stare at Peanuts comic strips, one frame at a time. The panels are without words, and while sometimes the action makes sense from frame to frame, at other times the Peanuts gang seems to be engaging in a series of unconnected shenanigans.
At the same time, a freshly minted Ph.D. named Neil Cohn is watching the readout from my brain, an exercise he has repeated with some 100 subjects to date. Many people would consider tracking Peanuts or Calvin and Hobbes comic strips unworthy of scientific inquiry, but Cohn begs to differ. His evidence suggests that we use the same cognitive process to make sense of comics as we do to read a sentence. They seem to tap the deepest recesses of our minds, where we bring meaning to the world.
Why Is it Impossible to Stop Thinking, to Render the Mind a Complete Blank?
Forgive your mind this minor annoyance because it has worked to save your life—or more accurately, the lives of your ancestors. Most likely you have not needed to worry whether the rustling in the underbrush is a rabbit or a leopard, or had to identify the best escape route on a walk by the lake, or to wonder whether the funny pattern in the grass is a snake or dead branch. Yet these were life-or-death decisions to our ancestors. Optimal moment-to-moment readiness requires a brain that is working constantly, an effort that takes a great deal of energy. (To put this in context, the modern human brain is only 2 percent of our body weight, but it uses 20 percent of our resting energy.) Such an energy-hungry brain, one that is constantly seeking clues, connections and mechanisms, is only possible with a mammalian metabolism tuned to a constant high rate.
Constant thinking is what propelled us from being a favorite food on the savanna—and a species that nearly went extinct—to becoming the most accomplished life-form on this planet. Even in the modern world, our mind always churns to find hazards and opportunities in the data we derive from our surroundings, somewhat like a search engine server. Our brain goes one step further, however, by also thinking proactively, a task that takes even more mental processing.
So even though most of us no longer worry about leopards in the grass, we do encounter new dangers and opportunities: employment, interest rates, “70 percent off” sales and swindlers offering $20 million for just a small investment on our part. Our primate heritage brought us another benefit: the ability to navigate a social system. As social animals, we must keep track of who’s on top and who’s not and who might help us and who might hurt us. To learn and understand this information, our mind is constantly calculating “what if?” scenarios. What do I have to do to advance in the workplace or social or financial hierarchy? What is the danger here? The opportunity?
For these reasons, we benefit from having a brain that works around the clock, even if it means dealing with intrusive thoughts from time to time.
(Source: scientificamerican.com)
Gladstone Scientists Identify Key Biological Mechanism in Multiple Sclerosis
Scientists at the Gladstone Institutes have defined for the first time a key underlying process implicated in multiple sclerosis (MS)—a disease that causes progressive and irreversible damage to nerve cells in the brain and spinal cord. This discovery offers new hope for the millions who suffer from this debilitating disease for which there is no cure.
Researchers in the laboratory of Gladstone Investigator Katerina Akassoglou, PhD, have identified in animal models precisely how a protein that seeps from the blood into the brain sets off a response that, over time, causes the nerve cell damage that is a key indicator of MS. These findings, which are reported in the latest issue of Nature Communications, lay the groundwork for much-needed therapies to treat this disease.
(Source: gladstoneinstitutes.org)
Preschoolers at play show science skills
When kids incessantly ask “Why?,” mess around in the dirt and run their hands over everything within reach, they’re not just being kids. It turns out they’re also being scientists.
Until recently, preschoolers were widely believed to be irrational thinkers. For most of the 20th century, the prevailing theory pioneered by cognitive development expert Jean Piaget held that children roughly ages 2 through 7 cannot understand concrete logic or other people’s perspectives.
Although young children are the only ones who truly know what they ponder, research conducted over the past decade has led many psychologists to see infants and toddlers as, in fact, capable of thinking logically and abstractly.
"The main thing is that they’re drawing conclusions from data and evidence and experiences the same way scientists are - by making hypotheses, testing them, analyzing statistics and even doing experiments, even though when they do experiments, it’s called ‘getting into everything,’ " said Alison Gopnik, a UC Berkeley psychology professor and one of the field’s leading experts.
Better understanding of how children learn about the world could have important implications for their formal schooling, Gopnik argued in a recent paper published in the journal Science, which summarized studies by her and other researchers.
New biomaterials promote neuroregeneration after a brain injury
Professor José Miguel Soria, a member of the Institute of Biomedical Sciences, Universidad CEU Cardenal Herrera, has co-directed with Professor Manuel Monleón of the Universitat Politècnica de València a study on the compatibility of polymeric biomaterials in the brain and its effectiveness to favour neuroregeneration in areas with some kind of damage or brain injury.
The research carried out has shown that these types of implants, made of a biocompatible synthetic material, are colonized within two months by neural progenitor cells and irrigated by new blood vessels. This allows the generation, within these structures, of new neurons and glia, capable of repairing injured brain tissue caused by trauma, stroke or neurodegenerative disease, among other causes.
The synthetic structures used in this study are made with a porous and biocompatible polymeric material called acrylate copolymer. In the first phase of the project, the structures have been studied in vitro by implanting them into neural tissue, and subsequently also in vivo, when implanted in two areas of the adult rat brain: the cerebral cortex and the subventricular zone, the most important source of generation of adult neural stem cells.
The study has confirmed the high biocompatibility of polymeric materials, such as acrylate copolymer, with brain tissue and opens new possibilities of the effectiveness of the implementation of these structures in the brain, seeking optimum location for developing regenerative strategies of the central nervous system.
Furthermore, the results are particularly relevant when one considers that in the adult brain neuroregeneration capacity is more limited than in younger individuals and that the main impediment for this is the lack of revascularization of damaged tissue, something that the biomaterial studied has shown to favour.
(Source: alphagalileo.org)
Brain Cooling to Treat Epilepsy Moves Closer to Human Application
Neuroscientists from Japan’s Yamaguchi University today reported during the 66th annual scientific meeting of the American Epilepsy Society (AES) that chronic focal brain cooling suppresses seizures during wakefulness and achieves the effect without significantly affecting brain function. Their research, and that of others in the field, provides critical evidence that this approach to seizure control has reached a stage where testing in humans will soon be possible.
Focal brain cooling is well established as an effective method for suppressing seizures. But the technology for creating a practical device with potential clinical application has only recently become available and tested in rodents. More evidence from large animals and humans is needed prior to testing in clinical trials for drug-resistant epilepsy.
The Yamaguchi researchers implanted two feline and two non-human primates with a titanium cooling plate, or heat exchanger. The brain cooling device was placed in contact with the brain surface over cortex areas responsible for movement and sensation. Seizures were then induced in the motor cortex. Brain wave recordings to assess seizure activity and temperature recordings were performed under wakefulness.
According to Masami Fujii, M.D.,Ph.D., and Takao Inoue, Ph.D., and Michiyasu Suzuki, M.D., Ph.D., who presented the report, seizure discharges were significantly suppressed at 15˚C (59˚F).
“The results of our study suggest that focal brain cooling has a strong effect to suppress the epileptiform seizures under the awake condition,” Dr. Fujii said. “Moreover, implantation of the device for at least five months did not result in detrimental changes in brain tissue subjected to cooling compared to tissue from a similar site in the opposing hemisphere.”
Extended sleep reduces pain sensitivity
A new study suggests that extending nightly sleep in mildly sleepy, healthy adults increases daytime alertness and reduces pain sensitivity.
"Our results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures," said Timothy Roehrs, PhD, the study’s principal investigator and lead author. "We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine."
The study, appearing in the December issue of the journal SLEEP, involved 18 healthy, pain-free, sleepy volunteers. They were randomly assigned to four nights of either maintaining their habitual sleep time or extending their sleep time by spending 10 hours in bed per night. Objective daytime sleepiness was measured using the multiple sleep latency test (MSLT), and pain sensitivity was assessed using a radiant heat stimulus.
Results show that the extended sleep group slept 1.8 hours more per night than the habitual sleep group. This nightly increase in sleep time during the four experimental nights was correlated with increased daytime alertness, which was associated with less pain sensitivity.
In the extended sleep group, the length of time before participants removed their finger from a radiant heat source increased by 25 percent, reflecting a reduction in pain sensitivity. The authors report that the magnitude of this increase in finger withdrawal latency is greater than the effect found in a previous study of 60 mg of codeine.
According to the authors, this is the first study to show that extended sleep in mildly, chronically sleep deprived volunteers reduces their pain sensitivity. The results, combined with data from previous research, suggest that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.