A New Way To Cross The Blood–Brain Barrier -  A Mental Unblock

A New Way To Cross The Blood–Brain Barrier -  A Mental Unblock

A New Way to Cross the Blood–Brain Barrier -  A Mental Unblock

The brain presents a unique challenge for medical treatment: it is locked away behind an impenetrable layer of tightly packed cells. Although the blood-brain barrier prevents harmful chemicals and bacteria from reaching our control center, it also blocks roughly 95 percent of medicine delivered orally or intravenously. As a result, doctors who treat patients with neurodegenerative diseases, such as Parkinson’s, often have to inject drugs directly into the brain, an invasive approach that requires drilling into the skull.

Some scientists have had minor successes getting intravenous drugs past the barrier with the help of ultrasound or in the form of nanoparticles, but those methods can target only small areas. Now neuroscientist Viviana Gradinaru and her colleagues at the California Institute of Technology show that a harmless virus can pass through the barricade and deliver treatment throughout the brain.

Gradinaru’s team turned to viruses because the infective agents are small and adept at entering cells and hijacking the DNA within. They also have protein shells that can hold beneficial deliveries, such as drugs or genetic therapies. To find a suitable virus to enter the brain, the researchers engineered a strain of an adeno-associated virus into millions of variants with slightly different shell structures. They then injected these variants into a mouse and, after a week, recovered the strains that made it into the brain. A virus named AAV-PHP.B most reliably crossed the barrier.

Next the team tested to see if AAV-PHP.B could work as a potential vector for gene therapy, a technique that treats diseases by introducing new genes into cells or by replacing or inactivating genes already there. The scientists injected the virus into the bloodstream of a mouse. In this case, the virus was carrying genes that encoded green fluorescent proteins. So if the virus made it to the brain and the new DNA was incorporated in neurons, the success rate could be tracked via a green glow on dissection. Indeed, the researchers observed that the virus infiltrated most brain cells and that the glowing effects lasted as long as one year. The results were recently published in Nature Biotechnology.

In the future, this approach could be used to treat a range of neurological diseases. “The ability to deliver genes to the brain without invasive methods will be extremely useful as a research tool. It has tremendous potential in the clinic as well,” says Anthony Zador, a neuroscientist who studies brain wiring at Cold Spring Harbor Laboratory. Gradinaru also thinks the method is a good candidate for targeting areas other than the brain, such as the peripheral nervous system. The sheer number of peripheral nerves has made pain treatment for neuropathy difficult, and a virus could infiltrate them all.

Image Credit: Thomas Fuchs

Source: Scientific American (By Monique Brouillette)

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This list is based off of the assumption that the infected individual does not receive medical treatment.

1. Prions (mad cow disease, Creutzfeld-Jakob disease, kuru, fatal familial insomnia): 100%

2. Rabies: ~100%

3. African trypanosomiasis (’African sleeping sickness’): ~100%

4. Primary amoebic encephalitis caused by Naegleri fowlerii (’the brain-eating amoeba’): ~100%

5. Yersinia pestis, specifically the pneumonic or septicemic subtype (’the black plague’): ~100%

6. Visceral leishmaniasis: ~100%

7. Smallpox, specifically the malignant (flat) or hemorragic subtype: 95%

8. Ebola virus, specifically the Zaire strain: 83-90%

9. HIV: 80-90%

10. Anthrax, specifically the pulmonary subtype: >85%


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8 years ago
(Image Caption: The Synapses Of Pyramid Cells In The Cerebral Cortex Form Functional Groups. Some Of

(Image caption: The synapses of pyramid cells in the cerebral cortex form functional groups. Some of the related synapses are shown in green in the reconstruction. Credit: © MPI of Neurobiology / Scheuss)

Neurons form synapse clusters

The cerebral cortex resembles a vast switchboard. Countless lines carrying information about the environment, for example from the sensory organs, converge in the cerebral cortex. In order to direct the flow of data into meaningful pathways, the individual pyramidal cells of the cerebral cortex act like miniature switchboard operators. Each cell receives information from several thousand lines. If the signals make sense, the line is opened, and the information is relayed onward. Scientists at the Max Planck Institute of Neurobiology in Martinsried have now shown for the first time that contact points between specific neuron types are clustered in groups on the target neuron. It is probable that signals are coordinated with each other in this way to make them more “convincing”.

The cells of the cerebral cortex have a lot to do. They process various types of information depending on the area in which they are located. For example, signals from the retina arrive in the visual cortex, where, among other things, the motion of objects is detected. The pyramidal cells of the cerebral cortex receive information from other cells through thousands of contact points called synapses. Depending on where, how many and how often synapses are activated, the cell relays the signal onward – or not.

Information is passed on in the form of electrical signals. The neurobiologists were able to measure these signals at various contact points of the neuron. “The exciting thing is that the signals that a cell receives from, say, ten simultaneously active synapses can be greater than the sum of the signals from the ten individual synapses,” says Volker Scheuss, summarizing the basis of his recently published study. “However, until now it was unclear whether this phenomenon can be explained by a specific arrangement of synapses on pyramidal cells.”

By combining modern methods, the neurobiologists in Tobias Bonhoeffer’s Department have analysed the arrangement of synapses. They were able to selectively activate a specific type of pyramid cell in brain slices from mice using optogenetics. Thanks to simultaneous “calcium imaging”, they were then able to observe and record the activity of individual synapses under a two-photon microscope. In this way, they succeeded in showing for the first time how synapses are arranged with respect to each other.

The result of such synapse mapping analysed with a newly developed algorithm was clear: The synapses of pyramidal cells form clusters consisting of 4 to 14 synapses arranged within an area of less than 30 micrometres along the dendrite. “The existence of these clusters suggests that the synapses interact with each other to control the strength of the combined signal,” explains Onur Gökçe, author of the study. This is the first anatomical explanation for the disproportionate strength of clustered synapse signals in comparison to the individual signals – a finding known from activity measurements. The observation in layer 5 pyramidal cells was of particular interest, as the activity of these cells oscillates synchronously. “This rhythmic activity, which probably influences the processing of visual information, could synchronously activate synapse clusters, thus boosting the overall signal received,” says Scheuss.


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8 years ago
After Centuries, Scientists Have Finally Figured Out How Water Conducts Electricity
One of life's most fundamental processes has been witnessed.

It’s a textbook moment centuries in the making: more than 200 years after scientists started investigating how water molecules conduct electricity, a team has finally witnessed it happening first-hand.

It’s no surprise that most naturally ocurring water conducts electricity incredibly well - that’s a fact most of us have been taught since primary school. But despite how fundamental the process is, no one had been able to figure out how it actually happens on the atomic level.

“This fundamental process in chemistry and biology has eluded a firm explanation,” said one of the team, Anne McCoy from the University of Washington. “And now we have the missing piece that gives us the bigger picture: how protons essentially ‘move’ through water.”

Continue Reading.


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8 years ago
The Blue Lava Of Kawah Ijen Volcano. The ‘blue Lavas’ Are A Rare Phenomenon, Only Visible On The
The Blue Lava Of Kawah Ijen Volcano. The ‘blue Lavas’ Are A Rare Phenomenon, Only Visible On The
The Blue Lava Of Kawah Ijen Volcano. The ‘blue Lavas’ Are A Rare Phenomenon, Only Visible On The
The Blue Lava Of Kawah Ijen Volcano. The ‘blue Lavas’ Are A Rare Phenomenon, Only Visible On The
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The Blue Lava of Kawah Ijen Volcano. The ‘blue lavas’ are a rare phenomenon, only visible on the Kawah Ijen Volcano, in Indonesia. It may look like the volcano is spewing blue lava, but in fact, the shocking blue fire occurs when the volcanic sulphuric gases combust. Emerging from cracks in the volcano’s side, these gases ignite when coming into contact with air. It’s not actual blue lava, but blue flames. (video)


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7 years ago
New Approach To Treating Alzheimer’s Disease

New Approach to Treating Alzheimer’s Disease

Alzheimer’s disease (AD) is one of the most common form of dementia. In search for new drugs for AD, the research team, led by Professor Mi Hee Lim of Natural Science at UNIST has developed a metal-based substance that works like a pair of genetic scissors to cut out amyloid-β (Aβ), the hallmark protein of AD.

The study has been featured on the cover of the January 2017 issue of the Journal of the American Chemical Society (JACS) and has been also selected as a JACS Spotlight article.

Alzheimer’s disease is the sixth leading cause of death among in older adults. The exact causes of Alzheimer’s disease are still unknown, but several factors are presumed to be causative agents. Among these, the aggregation of amyloid-β peptide (Aβ) has been implicated as a contributor to the formation of neuritic plaques, which are pathological hallmarks of Alzheimer’s disease (AD).

As therapeutics for AD, Professor Lim suggested a strategy that uses metal-based complexes for reducing the toxicity of the amyloid beta (Aβ). Althought various metal complexes have been suggested as therapeutics for AD, none of them work effectively in vivo.

The research team has found that they can hydrolyze amyloid-beta proteins using a crystal structure, called tetra-N methylated cyclam (TMC). Hydrolysis is the process that uses water molecules to split other molecules apart. The metal-mediated TMC structure uses the external water and cut off the binding of amyloid-beta protein effectively.

In this study, the following four metals (cobalt, nickel, copper and zinc) were placed at the center of the TMC structure. When the double-layered cobalt was added to the center, the hydrolysis activity was at the highest.

The research team reported that the cobalt-based metal complex (Co(II)(TMC)) had the potential to penetrate the blood brain barrier and the hydrolysis activity for nonamyloid protein was low. Moreover, the effects of this substance on the toxicity of amyloid-beta protein were also observed in living cell experiments.

“This material has a high therapeutic potential in the treatment of Alzheimer’s disease as it can penetrate the brain-vascular barrier and directly interact with the amyloid-beta protein in the brain,” says Professor Lim.

This study has also attracted attention by the editor of the Journal of the American Chemical Society. “Not only do they develop new materials, but they have been able to propose details of the working principles and experiments that support them,” according to the editor.

“As a scientist, this is such a great honor to know that our recent publication in JACS was highlighted in JACS Spotlights,” says Professor Lim. “This means that our research has not only been recognized as an important research, but also has caused a stir in academia.”


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8 years ago
Solidification Of Liquid Gallium 
Solidification Of Liquid Gallium 
Solidification Of Liquid Gallium 
Solidification Of Liquid Gallium 

Solidification of liquid Gallium 

Gallium is a chemical element with symbol Ga and atomic number 31. Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures, and melts at 29.76 °C (85.57 °F) (slightly above room temperature). Elemental gallium is not found in nature, but it is easily obtained by smelting.

Gallium metal expands by 3.1% when it solidifies, and therefore storage in either glass or metal containers are avoided, due to the possibility of container rupture with freezing. Gallium shares the higher-density liquid state with only a few materials, like water, silicon,germanium, bismuth, and plutonium.

Giffed by: rudescience  From: This video


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8 years ago
This Team Of Early Female Astronomers Created The Star Classification System We Use Today.
This Team Of Early Female Astronomers Created The Star Classification System We Use Today.
This Team Of Early Female Astronomers Created The Star Classification System We Use Today.
This Team Of Early Female Astronomers Created The Star Classification System We Use Today.

This team of early female astronomers created the star classification system we use today.

In the late 19th century, astronomy was a growing field. At the time, Edward Pickering, the director of the Harvard College Observatory, was working to create a classification system for stars by capturing the light from these distant celestial objects onto photographic glass plates. A team of female assistants and astronomers meticulously maintained and analyzed these delicate negatives. In her new book, The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars, Dava Sobel shares the stories of these female “human computers” and how their work helped to advance the field of astronomy and the role of women in science.

This team of astronomers included Williamina Fleming, who was once Pickering’s maid but eventually became a supervisor to the group and went on to identify hundreds of variable stars. And Henrietta Swan Leavitt’s observations about the luminosity of stars would shape later ideas about the expanding universe.

Listen to the interview here.

[Photos courtesy of The Glass Universe]


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8 years ago

Largest Batch of Earth-size, Habitable Zone Planets

Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.

image

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.

image

Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

image

This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.

All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

image

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.

image

In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.

image

For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.

The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.

image

 The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.

image

The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.

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Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer. 

How Did the Spitzer Space Telescope Detect this System?

Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system. 

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Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.

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The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.

At 40 light-years away, humans won’t be visiting this system in person anytime soon…that said…this poster can help us imagine what it would be like: 

image

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com


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8 years ago

It is imperfection - not perfection - that is the end result of the program written into that formidably complex engine that is the human brain, and of the influences exerted upon us by the environment and whoever takes care of us during the long years of physical, psychological and intellectual development.

Rita Levi-Montalcini

image

Image Credit: Hammersmith Hospital in London

(via neuromorphogenesis)


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contradictiontonature - sapere aude
sapere aude

A pharmacist and a little science sideblog. "Knowledge belongs to humanity, and is the torch which illuminates the world." - Louis Pasteur

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