Two recent studies are refuting the claims of omega-3 enthusiasts that the fatty acid, which is produced mainly by algae and is found in the animals that eat them (like fish), is the ultimate “brain food.”
Anecdotal reports had suggested that these fatty acids, called omega-3 because they have a kink in their structure three bonds from the end of the carbon chain, could improve brain function for everyone from the elderly to the unborn. Vitamin supplements of fish oil have therefore been flying off the shelves.
People who eat lots of fish are less likely to develop dementia or cognitive problems late in life. Observational studies have also found that taking omega-3s during pregnancy can reduce postpartum depression and improve neurodevelopment in children. What’s more, animals with an Alzheimer’s-like condition are helped by docosahexaenoic acid (DHA), one of several omega-3 fatty acids. And DHA disappears from the brains of people with Alzheimer’s. [ScienceNOW]
In an Alzheimer’s study published in The Journal of the American Medical Association, researcher Joseph Quinn gave about 400 patients suffering from mild to moderate Alzheimer’s 2 grams of either omega-3 DHA or a placebo each day. After 18 months, none of the patients showed improvement of their Alzheimer’s symptoms.
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From Ed Yong:
The best poker players are masters of deception. They’re good at manipulating the actions of other players, while masking their own so that their lies become undetectable. But even the best deceivers have tells, and Meghana Bhatt from Baylor University has found some fascinating ones. By scanning the brains and studying the behaviour of volunteers playing a simple bargaining game, she has found different patterns of brain activity that correspond to different playing styles. These “neural signatures” separate the players who are adept at strategic deception from those who play more straightforwardly.
For more about what Bhatt’s study revealed—and to figure out whether you’d be an “incrementalist,” a “conservative,” or a “strategist” kind of player—check out the rest of the post at DISCOVER blog Not Exactly Rocket Science.
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80beats: A Hide-and-Seek-Playing Robot Learns How to Lie
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Image: flickr / Morberg
For DARPA, the secretive military research agency, it’s not enough for a prosthetic limb to simply resemble a normal one, or for a patient to be able to move it through some remote control. DARPA-backed engineers are attempting to build a system in which peripheral nerves would be reattached to artificial limbs, which could send signals to a brain sensor that could reply. This would be a vast improvement over prosthetics that require conscious directives, and could turn a prosthetic into something that responds the way an ordinary limb would.
Darpa’s after a prosthetic that can record motor-sensory signals right from peripheral nerves (those that are severed when a limb is lost) and then transmit responding feedback signals from the brain. That means an incredibly sensitive platform, “capable of detecting sufficiently strong motor-control signals and distinguishing them from sensory signals and other confounding signals,” in a region packed tightly with nerves. Once signals are detected, they’ll be decoded by algorithms and transmitted to the brain, where a user’s intended movements would be recoded and transmitted back to the prosthetic. [Wired.com]
According to the team behind the system at Johns Hopkins University’s Applied Physics Laboratory, tests on monkeys have shown that the primates have remarkable success controlling a prosthesis through a cortical chip implanted in their brains, and researchers have undertaken some human tests. What remains to be seen, though, is how much dexterity people can get through this process.
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According to a new study out in Science Translational Medicine, treating depressed mice with gene therapy in the brain to bolster a protein connected to the neurotransmitter serotonin can make those depressive symptoms dissipate.
Here’s the gist: The gene in question creates a protein called p11 that help carry serotonin receptors up to the surface of a brain cell where they can receive signals from other brain cells. Poor serotonin signaling may be one of the major drivers behind depression, and a dearth of p11 could worsen the problem, according to study author Michael Kaplitt.
“In the absence of p11, a neuron can produce all the serotonin receptors it needs, but they will not be transported to the cell surface,” said Kaplitt. [AFP]
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Next time you’re at the pub with friends, take it easy on the lightweights—the ones who are getting a little silly after just a couple of drinks. That might be a blessing in disguise, according to a new study, because the 10 to 20 percent of people whose genetics make them especially sensitive to booze might also be at greatly reduced risk to develop alcoholism.
In the journal Alcoholism: Clinical and Experimental Research, Kirk Wilhelmsen and colleagues identified a particular gene associated with the easily intoxicated. The gene in question encodes an enzyme called CYP2E1, responsible for metabolizing not just alcohol in the brain, but also other substances like acetaminophen (Tylenol).
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A new drug seems to be able to reverse normal age-related memory decline in old mice–like a face-lift for neurons, bringing them back to their younger days. The results of the experimental treatment, which works by blocking certain stress hormones, were published in the Journal of Neuroscience.
“What’s most surprising is that even short-term inhibition was able to reverse memory loss in old mice,” says Jonathan Seckl, a professor of molecular medicine who was involved in the research. “I don’t think people had realized this was so reversible. It takes [the animals] back to being relatively young.” [Technology Review].
Research has shown that stress hormones called glucocorticoids play a role in memory loss, by damaging the brain over time. But targeting the glucocorticoids themselves is dangerous, because reducing their levels would leave the body without a stress response. The researchers therefore targeted an enzyme instead, which activates the hormone in neurons.
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When people suffer a concussion, is the evidence of that head trauma just hanging out in their bloodstream, waiting to be found? A U.S. Army project made news late last week by claiming to have found a biomarker for traumatic brain injury, which could allow for a simple diagnosis via blood test.
Make no mistake—a biomarker would be a tremendous medical advance in catching an elusive and hard-to-quantify condition. But don’t get too excited just yet: This was a preliminary study, and some other neuroscientists are not convinced the test will work on in a real, clinical trail.
Army Col. Dallas Hack, who has oversight of the research, says recent data show the blood test, which looks for unique proteins that spill into the blood stream from damaged brain cells, accurately diagnosing mild traumatic brain injury in 34 patients. Doctors can miss these injuries because the damage does not show up on imaging scans, and symptoms such as headaches or dizziness are ignored or downplayed by the victims. [USA Today]
Hack certainly wasn’t going to downplay the achievement by his team, which partners with the Florida-based company Banyan Biomarkers on this project.
Army Col. Dallas Hack says the new technique could rival the discovery of unique proteins in the 1970s that help doctors identify heart disease. “This will in fact do for brain injury what that test did for chest pain,” Hack said. “It’s going to change medicine entirely.” [UPI]
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A brain is a terrible thing to waste–and your brain knows that. A new study of congenitally deaf cats has shown that some parts of their brains which would typically work on hearing are repurposed, and instead help out with vision. As a result of that clever efficiency, these deaf cats have superior peripheral vision and motion-detection abilities than cats with normal hearing.
Researchers say the human brain may perform the same trick.
For years, researchers have known that deaf people often have superior peripheral vision and motion detection, but just how the brain creates these advantages was unclear. “Over the years, we’ve speculated about how these changes might be taking place,” says neuroscientist Helen Neville of the University of Oregon in Eugene, but a clear cause has been elusive. [Science News]
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The size of a small part of the brain, right behind the eyes, is connected with a person’s ability to gauge how likely they are to be right about factual questions, according to a study published in Science last week. This faculty is important in many real-world decisions; it can make the difference between relying on our mistaken judgment and asking for help if we realize we might be wrong.
The study’s lead author uses the game show Who Wants To Be a Millionaire? as an prime example of this kind of “metacognition,” or thinking about our own thinking:
“You might have the opportunity to ask the audience or phone a friend,” says Steve Fleming, a neuroscientist at University College London. But, he adds, “You need to know how sure you are about your own answer before you opt to use those lifelines.” [NPR]
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“Hongerwinter,” or “hunger winter”—that’s what they called the end of 1944 in the Netherlands. As World War II lurched toward its end, Nazi Germany put up a blockade to prevent food from entering the Netherlands. According to a study by Dutch researchers, that famine is still felt all these years later in the brains of people who were born during those years.
Susanne de Rooij and colleagues looked at more than 700 people born during those years, 300 of whom experienced famine in utero, to see if that experience changed their brains.
In the study, 64 seniors who were exposed to famine in the early stages of gestation did worse on cognitive-function tests that required them to do tasks like name the color of the word “blue” when it was printed in yellow ink, than seniors who were exposed later or not at all to hunger in utero. The researchers also found that exposure to famine at any stage of the mother’s pregnancy resulted in a smaller head circumference at ages 56-59.”Head size is related to brain size and reduced size has been associated with decreased cognitive abilities in the elderly,” they wrote. [AFP]
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Cockroaches take advantage of our messy hospitality, skulking around in the cracks and holes of our houses and devouring the scraps we leave behind. Soon, though, maybe we’ll be the ones taking advantage of their fondness for filth.
The brains of these insects carry some serious antibiotics—strong enough to slaughter bacteria that have evolved resistance to the hospital antibiotics we use. The researchers presented their work at the Society for General Microbiology meeting this week in England, and say that while the finding is terrific, it’s no surprise given the roaches’ living circumstances:
“Some of these insects live in the filthiest places ever known to man,” says Naveed Khan, coauthor of the new study. “These insects crawl on dead tissue, in sewage, in drainage areas. We thought, ‘How do they cope with all the bacteria and parasites?’” [Science News]
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Your pencil marks on the door frame mark your kids’ ascending height; your photo albums carry the visual record of their ascending ages. Scientists have figured out a new way to track growing up: studying the normal evolution of connections between parts of the brain as a person ages toward adulthood. If advanced far enough, such a method could even help to catch developmental disability.
In a study out this week in Science, the team led by Nico Dosenbach outline the technique based on functional connectivity MRI, or fcMRI. Where the MRI scans we cover more frequently typically reveal brain structure or activity in a particular region, fcMRI focuses on the connections across the brain.
The research team scanned the brains … of 238 normally developing subjects aged 7 to 30, for five minutes. By comparing 200 of 12,720 key functional brain connections and assessing them through multivariate pattern analysis, researchers then predicted volunteer subjects’ developmental status. [Scientific American]
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One headline reads “Doing Puzzles ‘Could Speed Up Dementia.’” Another, “Brain Exercise Helps Stave Off Dementia.” They’re both about the same new study out in Neurology this week. So which is it?
Both are shades of the truth, actually. Here’s what the scientists actually found:
Robert Wilson and his colleagues have been tracking more than a thousand people as part of their long-term study, begun in the early 1990s. The patients were 65 or older and the scientists interviewed them every three years.
Participants indicated on a 5-point scale how often they participated in seven activities: viewing television, listening to radio; reading newspapers; reading magazines; reading books; playing games like cards or doing puzzles; and going to museums. (A rating of 5 meant a person did some of these activities about every day; 3 meant several times a month; 1 meant once a year or less) [LiveScience].
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Ketamine for bipolar disorder. LSD for depression. It’s been a busy month for psychedelic drugs in the laboratory, as several studies showed that these drugs typically used recreationally—and illegally—affect the brain in ways that could make them useful for treating mental illness.
First came a small study in the Archives of General Psychiatry that we covered earlier this month, in which scientists tested 18 patients who on average had tried seven kinds of drugs to treat their bipolar disorder. When the researchers gave them small doses of ketamine—a powerful anesthetic that people use recreationally for the hallucinogenic side effects—the patients’ depressive symptoms lessened within a matter of minutes.
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How can some sleepers doze through anything from the rattle of a jackhammer to the blast of a jet engine? According to a new study, an extra helping of brain activity in the thalamus–a region tied to the senses–may give some people a better chance at blocking sleep-disturbing sounds.
“I hear complaints a lot as a sleep doctor that noises are interrupting people’s sleep all the time,’’ said Dr. Jeffrey M. Ellenbogen, chief of the division of sleep medicine at Harvard Medical School [and co-author of the study]. “What is it in the brain that makes it have less response to noise at night, and how can we enhance that natural occurring brain-based process to help people sleep?” he said. [The New York Times]
Researchers at the Harvard Medical School asked twelve healthy volunteers to spend three nights in a sleep lab. The first night the researchers let them sleep soundly, but monitored their brain activity. The following two nights, they used four speakers aimed at the sleepers’ heads to play sounds of air and car traffic, ringing telephones, and “hospital-based mechanical sounds,” among other things. They found that those people whose thalami produced more high-frequency signals called “sleep spindles” lasted the longest when barraged with noises: the more sleep spindles, apparently, the better the sleep. The study appears today in Current Biology.
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