What’s the News: When prions or amyloids make the news, it’s usually because they cause mad cow disease or Alzheimer’s—prions, after all, cause any proteins they touch to become as misfolded as they are, and amyloids, which are large clumps of wadded-together proteins, can jam the workings of cells.
The many-times-magnified photos of the Nikon Small World photomicrography contest entrance us year after year, with mesmerizing close-ups of nature’s microscopic marvels. Now, in the first Small World in Motion movie competition, we get to see the world’s wee wonders in action. The three winning films and eleven honorable mentions chronicle circulating blood, budding yeast, gestating eggs, and more.
First Place: This time-lapse video, at 10x magnification, traces the path of ink injected into an artery of a three-day-old chick embryo. As the ink spreads through the chick’s vascular system, the branching blood vessels and beating heart become clearly visible.
A protein tangle in an Alzheimer’s-afflicted neuron
Exactly how Alzheimer’s disease proliferates through the brain, overtaking one region after another, has eluded scientists. As the disease progresses, tau—a malformed protein that forms snarls and tangles inside neurons—shows up in more and more brain areas. Researchers have wondered whether tau, and the disease, are working their way out from a single area of origin or mounting numerous, distinct attacks on vulnerable parts of the brain. Two new studies in mice provide strong support for the first idea: Tau seems to pass from affected cells to their neighbors, spreading much the same way a virus or bacteria infection would.
Party hats out, everyone! Stephen Hawking turned 70 years old yesterday, 49 years after being told he had fewer than four left to live.
The Cambridge professor suffers from a motor neuron disease related to Lou Gehrig’s disease that has gradually taken from him his ability to move, feed himself, and speak, except through a synthesizer that he operates using a cheek muscle (unfortunately, his control of that muscle is also fading). But despite these handicaps, he has survived to an incredible ripe old age—the average for an Englishman is currently 77.2—and has continued his work as a cosmologist and physicist throughout. How has he managed to live so much longer than expected? (more…)
The colors that letters and numbers appear to a synesthete
What’s the News: For most of us, our senses stay relatively separate: that is, we hear what we hear and see what we see. People with synesthesia, however, actually see words as colors, taste a particular flavor when they hear a familiar song, or experience other strong, automatic linkages between senses. The neurological underpinnings of the condition—how the brain connects two usually distinct senses—have remained a mystery. But researchers have now found a possible cause, they reported yesterday: neurons in the area responsible for the second sensation, such as the color that goes with the word, may be unusually excitable.
What’s the News: Scientists have reversed Parkinson’s disease-like brain damage and motor problems in mice and rats using neurons grown from human embryonic stem cells. The new technique, described online in Nature earlier this week, brings scientists closer to similar treatments for people with Parkinson’s.
What’s the News: Trouble sticking to your diet? It may not be entirely your fault. Scientists, reporting in the journal Cell Metabolism, have now learned that when you starve yourself of calories, your brain cells also starve, causing your neurons to begin eating parts of themselves for energy. The self-cannibalism, in turn, cranks up hunger signals. This mouse study may lead to better treatments for human obesity and diabetes.
What’s the News: Scientists have built a brain implant that can restore lost memories and reinforce new ones. The implant, tested in a recent study in rats, brings back a memory by recording and replaying the electrical activity of neurons in a part of the hippocampus, the brain’s long-term memory center. While the device is far from ready for use in humans, it’s an important step toward memory-boosting implants that could one day help patients who have developed dementia or suffered a stroke.
What’s the News: Researchers have considerably weakened—and perhaps even erased—long-term memories in Aplysia, a type of marine slug, and in neurons in a lab dish, by blocking the activity of a particular enzyme. Understanding how to weaken and erase such memories could one day lead to new treatments for people suffering from post-traumatic stress disorder, who are haunted by memories of traumatic events.
What’s the Context: What’s the News: Researchers have grown neurons from the cells of people with schizophrenia, in a study published online yesterday in Nature, the first time a complex mental illness has been modeled with living cells in a lab. This approach provides a new way to probe the little-understood biological processes underlying the disease and to test potential drug treatments. In preliminary experiments, the researchers found that the neurons weren’t as interconnected as healthy neurons are, and that individual patients’ neurons differ in their reaction to various drugs used to treat schizophrenia.
When you engage in a long cell phone conversation, a new study says, the phone radiation may increase the brain activity in regions nearest to the antenna. It’s the newest entry into the long-running debate about whether cell phones carry health risks, but the scientists behind the research in the Journal of the American Medical Association caution that they don’t know what this localized change in brain activity means—or even how it’s happening.
Many previous studies of cell phone safety have looked into the question of whether the phones’ radiation could cause cancer (there’s no solid evidence that it could) or looked at the effects of the heat that phones create. But Nora Volkow and colleagues investigated something else: The metabolism of the brain regions nearest to the phone—that is, how quickly they are burning energy. To do it, Volkow’s team recruited 50 people and subjected them to PET scans while an active cellphone sat next to their heads.
To blind the participants, the authors strapped two cell phones on their heads, one to each ear (the cellphone used in this work is a standard Samsung CDMA flip phone). Both were kept muted, and only one was activated by a call—the side that was activated was flipped in two different recording sessions. The calls started 20 minutes before a dose of radioactive glucose, and kept going for a half an hour afterwards to provide a long-term picture of metabolic activity. The data from one of the subjects ended up not being used because the cell company dropped the call. [Ars Technica]
The burgeoning field of optogenetics—using shot of light on neurons to control behavior—has already produced some intruiging and peculiar results. Now add one more: Scientists can use it to make mice angry and aggressive.
With a pulse of light, Dayu Lin from New York University can turn docile mice into violent fighters – it’s Dr Jekyll’s potion, delivered via fibre optic cable. The light activates a group of neurons in the mouse’s brain that are involved in aggressive behaviour. As a result, the mouse attacks other males, females, and even inanimate objects.
Lin focused on a primitive part of the brain called the hypothalamus that keeps our basic bodily functions ticking over. It lords over body temperature, hunger, thirst, sleep and more. In particular, Lin found that a small part of this area – the ventrolateral ventromedial hypothalamus (VMHvl) – acts as a hub for both sex and violence.
Scientists are devising cleverer and cleverer means to see inside the brain—and creating some amazing pictures along the way.
These psychedelic images come from one of two studies in the journal Nature Methods, which present similar but slightly different ways to color the connections between neurons in a fruit fly. The projects build upon similar research from 2007 that achieved this “brainbow” effect in mice, and they could allow for new ways to track the formation and purpose of brain cells.
The researchers gave the insects genes for a red, a green, and a blue fluorescent protein. The genetic control system they devised spurs each cell to make a different amount of each of the three proteins. Like the red, blue, and green pixels on a TV screen, the combination of the three proteins causes each cell to glow a unique color. [ScienceNOW]
The inserted genes come from naturally glowing jellyfish. They allow not just individual cells to be seen, but also connections:
The long wait is over: Scientists have achieved laser-driven mind control over moving, squirming worms.
Taking advantage of the emerging technique of optogenetics, Harvard researchers report in the journal Nature Methods that they can target any individual neuron of the tiny transparent worm C. elegans, whether the creature is moving or at rest, and zap it with a laser to see what the particular cell does—move the worm to the left or right, or even cause it to lay eggs.
The whole process, from finding the cell to light hitting its target, takes about 20 milliseconds. As the worm’s position changes, that information is fed back into the computer program, and the laser is adjusted. If the worm crawls too far, a motorized microscope stage brings the animal back. One of the biggest benefits of the new method, [biologist William] Ryu says, is that it works in a roving animal. “The worms are not held down in any way — they’re freely moving. There aren’t many systems where you can look at such truly free organisms.” [Science News]
In recent weeks we’ve covered new experimental treatments that involve injecting stem cells into patients to treat conditions like stroke and spinal injury. But in a new study, British researchers have pinpointed the possibility—in rats at least—of stimulating the body’s own stem cells to repair the chronic damage brought on by multiple sclerosis.
In MS patients, the immune system mistakenly attacks what’s called the myelin sheath, the protective layer around the axons of nerve cells.
The loss of myelin in MS sufferers leads to damage to the nerve fibres in the brain that send messages to other parts of the body, leading to symptoms ranging from mild numbness to crippling paralysis. [AFP]
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
What’s the News: Scientists have built a brain implant that can restore lost memories and reinforce new ones. The implant, tested in a recent 
Aplysia californica
What’s the Context:
In recent weeks 
