We all need to clear our heads, sometimes literally — and now scientists have learned how our neurological plumbing system works.
Every organ produces waste, and the brain is no exception. But unlike the rest of our body, it doesn’t have a lymphatic system, a network of vessels that filter out junk. Now, a new study of mouse brains suggests how ours handle waste: by rapidly pumping fluid along the outside of blood vessels, literally flushing waste away. The finding, reported Aug. 15 in Science Translational Medicine, could hint at how diseases like Alzheimer’s develop and might be treated.
“If you look at a body-wide map of the lymphatic system, you see a great big void in the brain,” said neuroscientist Jeffrey Iliff of the University of Rochester Medical Center. He and his colleagues found that puzzling, given how active the brain is and how sensitive it is to waste buildup.
Scientists long suspected that the brain’s refuse ended up in the cerebrospinal fluid, which cushions the brain inside the skull. In the 1980s, some researchers proposed that the fluid might be pumped into the brain to wash it, then pumped out again. Other researchers weren’t convinced.
Thanks to new imaging techniques that made it possible to peer inside the brain of a living mouse, Iliff’s team saw the process in action. Cerebrospinal fluid flowed along the outside of blood vessels, carried through a network of pipe-like protein structures. The fluid picked up waste that accumulated between cells, then drained out through major veins.
“These experiments validate a powerful ‘prevailing current’ of cerebrospinal fluid in brain extracellular space that effectively clears metabolic garbage,” said neurologist Bruce Ransom of the University of Washington, who was not affiliated with the study.
Iliff’s group went on to show that mice brains without these channels did poorly at clearing waste, including amyloid protein, buildup of which is linked to Alzheimer’s disease. They cleared waste 70 percent more slowly than mice possessing the channels.
Healthy brains produce amyloid normally, but this system clears it out frequently, the researchers suspect. In an Alzheimer’s brain, ”it builds up and builds up and builds up, until eventually it forms the plaques that can clog up the brain,” said Iliff.
In theory, you could prevent or slow that buildup by improving the brain’s flushing system. “The key is, we have to find a way to ‘turn up’ the system,” Iliff said. This could also apply to other brain conditions, such as Parkinson’s disease or stroke.
Iliff and colleagues used a combination of old and new imaging methods to visualize fluid circulation. The standard method involves injecting a radioactive tracer chemical into a slice of brain tissue, shining light on it, and watching how it fluoresces (above right). But this method only provides snapshots of dead brains. With a new technique called two-photon imaging, which can detect radioactive tracers hit with just two low-energy photons, the researchers could see deep into the brain of a living mouse.
More research is needed to fully understand how the waste system works in human brains, which can’t be studied as easily as mice. Still, the findings are important, said Ransom. “After decades of uncertainty about cerebrospinal fluid movement in brain, we finally know which way the wind is blowing,” he said.
Citation: “A Paravascular Pathway Facilitates CSF Flow Through the Brain Parenchyma and the Clearance of Interstitial Solutes, Including Amyloid β.” By Jeffrey J. Iliff, Minghuan Wang, Yonghong Liao, Benjamin A. Plogg, Weiguo Peng, Georg A. Gundersen, Helene Benveniste, G. Edward Vates, Rashid Deane, Steven A. Goldman, Erlend A. Nagelhus, Maiken Nedergaard. Science Translational Medicine, Vol. 4 Issue 147, August 15, 2012.
Scientists: Climate change forced Egyptians to stop building pyramids
Ancient pollen and charcoal preserved in deeply buried sediments in Egypt’s Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt’s Old Kingdom, the era known as the pyramid-building time.
A newly released study finds that drought brought on by climate change may have ended the era of pyramid building in Egypt.
The study, conducted by USGS and University of Pennsylvania, finds that a series of extreme droughts and Scientists examined 7,000-year-old ancient pollen and charcoal samples from the Nile to piece together the time – and found evidence of a ‘mega drought’ in the the area. The study notes that wetland pollen decreased during droughts, while charcoal use increased. Researchers says that the presence of charcoal was considered to be highest some 5,000 to 5,500 years ago.
“Humans have a long history of having to deal with climate change,” said Christopher Bernhardt, a researcher with the U.S. Geological Survey. “Along with other research, this study geologically reveals that the evolution of societies is sometimes tied to climate variability at all scales – whether decadal or millennial.”
The team of researchers noted that the study reveals that humans have struggled to cope with the effects of drought. The team of geologists said fossilized material from the region provided data that shows Egyptians struggling to adjust to the growing challenge of climate change. The researchers studied pollen and charcoal preserved in a Nile Delta sediment core that dates back 7,000 years, some of the oldest samples recovered.
“Even the mighty builders of the ancient pyramids more than 4,000 years ago fell victim when they were unable to respond to a changing climate,” said USGS Director Marcia McNutt. “This study illustrates that water availability was the climate-change Achilles Heel then for Egypt, as it may well be now, for a planet topping seven billion thirsty people.”
The study comes as climate change remains a major issue for several governments around the world. International policy makers have struggled to address the issue in recent years, however, various international summits have failed to build a consensus over the best possible path towards lowering emissions of greenhouse gases.
These events are also recorded in human history – the first one started some 5,000 years ago when the unification of Upper and Lower Egypt occurred and the Uruk Kingdom in modern Iraq collapsed. The second event, some 3,000 years ago, took place in the eastern Mediterranean and is associated with the fall of the Ugarit Kingdom and famines in the Babylonian and Syrian Kingdoms, according to scientists.
Mr. Bernhardt along with Benjamin Horton, an associate professor in Penn’s Department of Earth and Environmental Science, conducted the study. Jean-Daniel Stanley at the Smithsonian Institution also participated in the study, published in July’s edition of Geology.
Support for the work came from the University of Pennsylvania, the U.S. Geological Survey, and the Smithsonian Institution.
A dramatic gash in the surface of the Earth that could rival the majesty of the Grand Canyon has been discovered secreted beneath Antarctica's vast, featureless ice sheet.
Dubbed the Ferrigno Rift for the glacier that fills it, the chasm's steep walls plunge nearly a mile down (1.5 kilometers) at its deepest. It is roughly 6 miles (10 km) across and at least 62 miles (100 km) long, possibly far longer if it extends into the sea.
The rift was discovered during a grueling 1,500-mile (2,400 km) trek that, save for a few modern conveniences, hearkens back to the days of early Antarctic exploration. And it came as a total surprise, according to the man who first sensed that something incredible was literally underfoot, hidden by more than a half-mile (1 km) of ice.
Robert Bingham, a glaciologist at the University of Aberdeen, along with field assistant Chris Griffiths, had embarked on a nine-week trip during the 2009-2010 field season to survey the Ferrigno Glacier, a region humans had visited only once before, 50 years earlier. Over the last decade, satellites have revealed the glacier is the site of the most dramatic ice loss in its West Antarctica neighborhood, a fringe of coastline just west of the Antarctic Peninsula — the narrow finger of land that points toward South America.
The two-man team set out aboard snowmobiles, dragging radar equipment behind them to measure the topography of the rock beneath the windswept ice, in a region notorious for atrocious weather. Braced for arduous, yet uneventful fieldwork, the surprise came right away. [Images: Antarctica's Icy Wilderness]
"It was literally one of the first days that we were driving across the ice stream, doing what we thought was a pretty standard survey, that I saw the bed of the ice just dropping away," Bingham said.
The drop was so sudden and so deep that Bingham drove back and forth across the area two or three more times to check the data, and saw the same pattern. "We got the sense that there was something really exciting under there," he told OurAmazingPlanet. "It was one of the most exciting science missions I've ever had."
Bingham compared the hidden chasm to the Grand Canyon in scale, but said that tectonic forces of continental rifting — in contrast to erosion — created the Ferrigno Rift, wrenching the fissure's walls apart probably tens of millions of years ago, when Antarctica was ice-free.
Excitement surrounding the discovery has deeper implications than the mere gee-whiz factor of finding such a massive feature. The Ferrigno Rift's "existence profoundly affects ice loss," Bingham and co-authors from the British Antarctic Survey wrote in a paper published in Nature today (July 25).
"The geology and topography under the ice controls how the ice flows," said Robin Bell, a geophysicist and professor at Columbia University's Lamont-Doherty Earth Observatory, who was not associated with the research. "Ice will flow faster over sediments, like those found in rifts," said Bell, a veteran Antarctic researcher, who has long studied yet another dramatic, yet invisible geological feature, the hidden Gamburtsev Mountains in East Antarctica.
In addition, the study authors write, the rift is providing a channel for warm ocean water to creep toward the interior of the West Antarctic Ice Sheet, gnawing away at the Ferrigno Glacier from below.
Together, these two factors could be speeding the glacier's march to the sea, and the overall effects could have implications for the stability of the West Antarctic Ice Sheet, which is responsible for 10 percent of global sea level rise that is currently happening.
Scientists are still only just beginning to understand the myriad mechanisms that control the seemingly dramatic melting observed in regions of West Antarctica, and how climate change is affecting all the moving parts.
"With something like the Antarctic ice sheet, some of these processes take centuries, and the amount of time we've been able to observe changes is at the maximum 20 years," Bingham said. "It's a very small amount of time."
New Medical Discovery A team of scientists at the Boston Children’s Hospital have invented what is being considered one the greatest medical breakthroughs.
A team of scientists at the Boston Children’s Hospital have invented what is being considered one the greatest medical breakthroughs in recent years. They have designed a microparticle that can be injected into a person’s bloodstream that can quickly oxygenate their blood. This will even work if the ability to breathe has been restricted, or even cut off entirely.
This finding has the potential to save millions of lives every year. The microparticles can keep an object alive for up to 30 min after respiratory failure. This is accomplished through an injection into the patients’ veins. Once injected, the microparticles can oxygenate the blood to near normal levels. This has countless potential uses as it allows life to continue when oxygen is needed but unavailable. For medical personnel, this is just enough time to avoid risking a heart attack or permanent brain injury when oxygen is restricted or cut off to patients.
Dr. John Kheir, who first began the study, works in the Boston Children’s Hospital Department of Cardiology. He found inspiration for the drug in 2006, when he was treating a girl in the ICU who had a sever case of pneumonia. At the time, the girl didn’t have a breathing tube, when at the time she suffered from a pulmonary hemorrhage. This means her lungs had begin to fill up with blood, and she finally went into cardiac arrest. It took doctors about 25 minutes to remove enough blood from her lungs to allow her to breath. Though, the girl’s brain was severely injured due to being deprived of oxygen for that long and she eventually died.
The microparticles used are composed of oxygen gas pocketed in a layer of lipids. A Lipid is a natural molecule that can store energy and act as a part of a cell membrane, they can be made of many things such as wax, vitamins, phospholipids, and in this case fat is the lipid that stores the oxygen.
These microparticles are around two to four micrometers in length and carry about three to four times the oxygen content of our own red blood cells. In the past, researchers had a difficult time succeeding as prior tests caused gas embolism. This meant that the gas molecules would become stuck trying to squeeze through the capillaries. They corrected this issue by packaging them into small deformable particles rather ones where the structure was rigid.
Potential Future Uses
Medical: There is the obvious medical uses where the microparticles can be used to save off death from a restriction in breathing due to inflammation of the lungs, collapsed lungs, and the like. It would be good to have these injections ready in hospitals and ambulances for when the time is needed.
Military: Can you imagine a navy seals capability when they wouldn’t need to surface for air and could stay underwater for over 20 minutes? If a boat was to begin to sink, you could shoot yourself as the boat is going down to ensure you aren’t drowned in the under current of the sinking vessel. How about for toxic gases when a facemask is unavailable. The military could have a number of uses for such a medical advancement.
Private Sector: Really this can be used as a precaution for anything nautical where the potential to drown is a real danger. Deep sea rescue crews could inject themselves prior to making a rescue, underwater welders can use it in case they become stuck or air is lost to their suits. The potential use for anything water related seems extremely worthwhile.
In the end, this is an amazing medical advancement and I cant help but recall the movie the Abyss when they took the pill, their helmets filled with air, and they were told they can breathe the water. Well what if they really couldn’t “breathe” water” but since the urge to breathe is natural, that must take place… even if you’re not breathing air per se. But your body was provided with enough oxygen for a time period by taking a pill. It’s just goes to show that anything, absolutely anything that can be thought up, can potentially one day become reality. Thank you scientists, for reminding me that people and their ingenuity are nothing short of awesome.
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Nature is a wondrous beauty as the ice age flower blooms after 32000 years of being non-existent.
According to Discover Magazine, Russian scientists announced that they had unearthed the fruit and brought tissue from it back to life. after the seeds were buried over 32000 years ago. The discovery was made in northwestern Siberia, where the winter team of Russian scientists found the seeds of the flower and regrew it. The plant breaks the previously held record of the oldest tissue to give life to healthy plants, which was previously held by the Israeli date palm seed.
In 1995, researchers studying and working with ancient soil composition in an exposed Siberian riverbank found 70 fossilized Ice Age squirrel burrows, some of which stored up to 800,000 seeds and fruits. With the help of the permafrost, the narrow-leafed campion plant tissue was preserved well enough for the team at the Russian Academy of Sciences to culture the cells to see if they would grow. The team, led by team leader Svetlana Yashina, were successful and re-created Siberian conditions in the lab and watched as the refrigerated tissue sprouted buds that developed into 36 flowering plants within weeks.
Tardigrades (commonly known as waterbears or moss piglets) are small, water-dwelling, segmented animals with eight legs. They form the phylum Tardigrada, part of the superphylum Ecdysozoa.
Tardigrades were first described in 1773 by Johann August Ephraim Goeze, who called them kleiner Wasserbär, meaning 'little water bear' in German. The name Tardigrada means "slow walker" and was given by Lazzaro Spallanzani in 1777. The name water bear comes from the way they walk, reminiscent of a bear's gait. The biggest adults may reach a body length of 1.5 millimetres (0.059 in), the smallest below 0.1 mm. Freshly hatched tardigrades may be smaller than 0.05 mm.
Some 1,150 species of tardigrades have been described. Tardigrades occur throughout the world, from the Himalayas (above 6,000 metres (20,000 ft)), to the deep sea (below 4,000 metres (13,000 ft)) and from the polar regions to the equator.
The most convenient place to find tardigrades is on lichens and mosses. Other environments are dunes, beaches, soil, and marine or freshwater sediments, where they may occur quite frequently (up to 25,000 animals per litre). Tardigrades often can be found by soaking a piece of moss in spring water.
Tardigrades are able to survive in extreme environments that would kill almost any other animal. Some can survive temperatures of close to absolute zero, or 0 Kelvins (−273 °C (−459 °F)), temperatures as high as 151 °C (304 °F), 1,000 times more radiation than other animals, and almost a decade without water. Since 2007, tardigrades have also returned alive from studies in which they have been exposed to the vacuum of outer space for a few days in low Earth orbit.