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Neurons Can Be Changed From One Type To Another, Communication Paths Rewired (harvard.edu) 31

schwit1 writes: A newly published study from Harvard biologists [here's a link to the paywalled paper's summary] shows how neurons can be dramatically changed from one type into another from within the brain and how neighboring neurons recognize the reprogrammed cells as different and adapt by changing how they communicate with them. Building on earlier work in which they disproved neurobiology dogma by "reprogramming" neurons — turning one form of neuron into another — in the brains of living animals, Harvard Stem Cell Institute researchers have now shown that the networks of communication among reprogrammed neurons and their neighbors can also be changed, or "rewired."

Symbolic vs. Mnemonic Relational Operators: Is "GT" Greater Than ">"? 304

theodp writes: "Mnemonic operators," writes SAS's Rick Wicklin as he weighs the pros-and-cons of Symbolic Versus Mnemonic Logical Operators, "tend to appear in older languages like FORTRAN, whereas symbolic operators are common in more recent languages like C/C++, although some relatively recent scripting languages like Perl, PHP, and Windows PowerShell also support mnemonic operators. SAS software has supported both operators in the DATA step since the very earliest days, but the SAS/IML language, which is more mathematically oriented, supports only the symbolic operators. Functionally, the operators are equivalent, so which ones you use is largely a matter of personal preference. Since consistency and standards are essential when writing computer programming, which operators should you choose?"

The Neuroscientist Who Tested a Brain Implant On Himself (technologyreview.com) 58

An anonymous reader writes: Our understanding of the brain has come a long way in the past thirty years, but most brain-related medical procedures remain incredibly complicated and dangerous. Neurologist Phil Kennedy has been working on brain-computer interfaces since the 1980s. He was most notably involved in letting a patient with "locked in" syndrome interact with the outside world through a brain-controlled computer cursor. But the FDA has gradually ramped up its safety demands, and in the past decade they've shut down Kennedy's research. So he did what any determined inventor would do: he went to a hospital in Belize and had surgeons there implant electrodes on his own brain so he could continue his research.

"After returning home to Duluth, Georgia, Kennedy began to toil largely alone in his speech lab, recording his neurons as he repeated 29 phonemes (such as e, eh, a, o, u, and consonants like ch and j) out loud, and then silently imagined saying them. ... Kennedy says his early findings are 'extremely encouraging.' He says he determined that different combinations of the 65 neurons he was recording from consistently fired every time he spoke certain sounds aloud, and also fired when he imagined speaking them—a relationship that is potentially key to developing a thought decoder for speech." Eventually, Kennedy had to have the implants removed, but he hopes the data he gathered will help push the FDA toward supporting this research once more.


You Can't Get Smarter, But You Can Slow How Fast You Get Dumber (nytimes.com) 82

An anonymous reader writes: An article at the NY Times summarizes the state of research on cognitive improvement. There are multiple industries — from big pharma to the makers of "brain-training" games — trying to convince you there are ways to become more intelligent. Unfortunately, scientific research doesn't really bear that out. There is, however, evidence you can provide short-term boosts, slow aging-related cognitive decline, and trick yourself into achieving better outcomes. Experiments show that simply telling a group of low-performing students that intelligence is malleable led to higher test scores. Researchers also found a use for mental exercises, but only in adults over the age of 60, a time at which some level of cognitive decline is common. Physical exercise seems to help fight that cognitive shrinkage as well. Oddly, different exercises fight it in different ways. As for drugs, there is some evidence that stimulants help with long-term memory, but that's about it. That's not to say they have no effect, just that their effect is more to make you feel smarter instead of actually being smarter. The article does point out one of the best ways to combat cognitive decline: maintain social engagement as you get older. "[P]eople with the highest level of social integration had less than half the decline in their cognitive function of the least socially active subjects."

Researchers Switch Neurons Off and On Using Noninvasive Ultrasound 37

Jason Koebler writes: Optogenetics, the ability to control neurons using bursts of light, has been one of the most promising breakthroughs in neurology of this decade. It's been a boon for researchers, but its invasive nature (the brain must usually be exposed) has held the technology back. Sreekanth Chalasani of the Salk Institute for Biological Studies described a new, noninvasive method of controlling neurons using ultrasound pulses in Nature Communications. For the first time ever, he was able to manipulate a genetically modified organism using a new technique called sonogenetics.

Finding Hope In Cryonics, Despite Glacial Progress 87

biobricks writes: The NY Times covers cryonics and destructive mind uploading, with some news on progress in brain preservation research. Quoting: "Dr. Fahy, a cryobiologist whose research focuses on organ banking, had provided the most encouraging signs that cryonics did preserve brain structure. In a 2009 experiment, his team showed that neurons in slices of rabbit brains immersed in the solution, chilled to cryogenic temperatures and then rewarmed, had responded to electrical stimulation. His method, he contended, preserved the connectome in those slices. But a complication prevented him from entering the prize competition: Brain tissue perfused with the cryoprotectant invariably becomes dehydrated, making it nearly impossible to see the details of the shrunken neurons and their connections under an electron microscope. ... He could fix the brain’s structure in place with chemicals first, just as Dr. Mikula was doing, buying time to perfuse the cryoprotectant more slowly to avoid dehydration. But he lacked the funds, he said, for a project that would have no practical business application for organ banking."

Brain-Eating Amoeba Scoffs At Chlorine In Water Pipes 151

An anonymous reader writes: The Naegleria fowleri amoeba typically feeds on bacteria in water and soil. Human digestive systems have no problem killing it, but inhaling water that carries the amoeba gives it the opportunity to work its way into the brain after it sneaks through the nasal mucus. It happens rarely, but 97% of people whose brains start swelling because of this amoeba end up dying. Like most microorganisms, N. fowleri can be neutralized with concentrated chlorine. However, the systems we use to deliver tap water aren't so clean. Researchers found that N. fowleri can easily survive for 24 hours when it's mixed with the types of biofilm that tend to reside in water pipes. Increasing chlorine levels isn't a good option, since its reaction with these biofilms can generate carcinogens.

Researchers Grow Tiny Human Brain In Lab 244

schwit1 writes: A team of researchers from Ohio State University claim to have grown a human brain in their lab that approximates the brain of a five-week-old fetus. They say the tiny brain is not conscious, but it could be used to test drugs and study diseases, but scientific peers urge caution. "The brain, which is about the size of a pencil eraser, is engineered from adult human skin cells and is the most complete human brain model yet developed, [the researchers say]. ... Anand and his colleagues claim to have reproduced 99% of the brain’s diverse cell types and genes. They say their brain also contains a spinal cord, signalling circuitry and even a retina." The team's data has not yet been peer reviewed.

Common Medications Sway Moral Judgment 132

sciencehabit sends news that two commonly-prescribed drugs have been shown to influence how the human brain makes moral decisions. Citalopram is an SSRI used to treat depression, and levodopa is often used to combat Parkinson's disease. A new study (abstract) asked subjects to set a monetary value on receiving painful electric shocks — for themselves and for others (e.g. "Would you rather endure seven shocks to earn $10 or 10 shocks to earn $15?"). The study found that subjects on citalopram (which affects serotonin levels) were willing to give up more money to reduce shocks, both for themselves and others. Those on levodopa (which affects dopamine levels) made people just as willing to shock others as they were to shock themselves, when those on a placebo tended to be more reluctant to shock others. [Neuroscientist Molly] Crockett says those effects could suggests multiple underlying mechanisms. For example, excess dopamine might make our brain's reward system more responsive to the prospect of avoiding personal harm. Or it could tamp down our sense of uncertainty about what another person is experiencing, making us less hesitant to dole out pain. Serotonin, meanwhile, appeared to have a more general effect on aversion to harm, not just a heightened concern for another person. Such knowledge could eventually develop drugs that address disorders of social behavior, she says.

High-Fat, High-Sugar Diet Can Lead To Cognitive Decline 244

An anonymous reader writes: Researchers from Oregon State University have completed a study into how the sugar and fat content of a diet relates to cognitive flexibility. They found that diets with high amounts of either led to a decline in cognitive function. "This effect was most serious on the high-sugar diet, which also showed an impairment of early learning for both long-term and short-term memory." After four weeks on a high-fat or high-sugar diet, the performance of mice on various mental and physical tests started dropping. One of the scientists, Kathy Magnusson, said, "We've known for a while that too much fat and sugar are not good for you. This work suggests that fat and sugar are altering your healthy bacterial systems, and that's one of the reasons those foods aren't good for you. It's not just the food that could be influencing your brain, but an interaction between the food and microbial changes."

Monitoring Brain Activity With Mesh Electronics 31

An anonymous reader writes: Medical researchers have long known that bioelectronics could substantially improve patient diagnosis and treatment, but the difficulty in putting that circuitry into place kept more traditional options at the forefront. Now, a team of scientists has found a clever way to deliver flexible electronic meshes via syringe, which could make it easier to monitor complex brain activity without dangerous surgery. "The scientists demonstrated they could inject a 2mm wide sample of the mesh through a glass needle with an inner diameter of only 95m. During injection, the mesh structure continuously unfolds as it exits the needle. Injection of the mesh through a needle with a 600m inner diameter produced similar results." The team has already tested the technique on rodents, and found minimal response from astrocytes, cells involved in repairing damaged brain tissue. They were able to record the rodents's brain activity as well.

Studying the Roots of Individuality 42

An anonymous reader sends an article from Quanta Magazine about research into individuality — how behavior varies (or doesn't) when genetics and environment are as similar as possible. Scientists are taking various strains of fruit fly that are genetically almost identical (the result of extreme inbreeding) and raising them alone in environments that are exact copies of each other. Then they run the fruit flies through a series of decision-making tests to see how varied their responses are. Some fruit fly strains show a high degree of variance for tasks like navigating a maze. Other strains show almost no variance, suggesting there's a genetic component to individuality. The scientists also found that manipulating a certain set of neurons in the fruit flies's brains could increase the variation in choices they make. One theory suggests that evolution tends to select for genes that increase individuality by making it more difficult for predators to predict what the prey will do next.

Space Radiation May Alter Astronauts' Neurons 73

sciencehabit writes: NASA hopes to send the first round-trip, manned spaceflight to Mars by the 2030s. If the mission succeeds, astronauts could spend several years potentially being bombarded with cosmic rays—high-energy particles launched across space by supernovae and other galactic explosions. Now, a study in mice suggests these particles could alter the shape of neurons, impairing astronauts' memories and other cognitive abilities. In the prefrontal cortex, a brain region associated with executive function, a range of high-level cognitive tasks such as reasoning, short-term memory, and problem-solving, neurons had 30% to 40% fewer branches, called dendrites, which receive electrical input from other cells.

Using Adderall In the Office To Get Ahead 407

HughPickens.com writes: The NY Times reports on the changing usage of psychostimulants like Adderall. They were once only prescribed to help children with attention deficit disorders focus on their school work, but then college students found those drugs could increase their ability to study. Now a growing number of workers use them to help compete. What will happen as these drugs are more widely used in the workplace? According to Anjan Chatterjee, the use of neurotechnologies to enhance healthy people's brain function could easily become widespread. "If anything, we worship workplace productivity by any means. Americans work longer hours and take fewer vacations than most others in the developed world. Why not add drugs to energize, focus and limit that annoying waste of time — sleep?" Julian Savulescu says that what defines human beings is their extraordinary cognitive power and their ability to enhance that power through reading, writing, computing and now smart drugs. "Eighty-five percent of Americans use caffeine. Nicotine and sugar are also cognitive enhancers," says Savulescu.

But cognitive neurologist Martha Farah says regular use on the job is an invitation to dependence. "I also worry about the effect of drug-fueled productivity on people other than the users," says Farah. "It is not hard to imagine a supervisor telling employees that this is the standard they should aspire to in their work, however they manage to do it (hint, hint). The eventual result will be a ratcheting up of "normal" productivity, where everyone uses (and the early adopters' advantage is only fleeting)."

Being Overweight Reduces Dementia Risk 97

jones_supa writes Being overweight cuts the risk of dementia, according to the largest and most precise investigation into the relationship (abstract). The researchers were surprised by the findings, which run contrary to current health advice. The team at Oxon Epidemiology and the London School of Hygiene and Tropical Medicine analyzed medical records from 2 million people aged 55 on average, for up to two decades. Their most conservative analysis showed underweight people had a 39% greater risk of dementia compared with being a normal healthy weight. But those who were overweight had an 18% reduction in dementia, and the figure was 24% reduction for the obese. Any explanation for the protective effect is distinctly lacking. There are some ideas that vitamin D and E deficiencies contribute to dementia and they may be less common in those eating more. Be it any way, let's still not forget that heart disease, stroke, diabetes, some cancers and other diseases are all linked to a bigger waistline. Maybe being slightly overweight is the optimum to strike, if the recent study is to be followed.

"If I do not want others to quote me, I do not speak." -- Phil Wayne