Depiction of Electrical signals that pass through the nerves

                 Depiction of Electrical signals that pass through the nerves

  • Musicians, athletes and quiz bowl champions all have one thing in common: training. Learning to play an instrument or a sport requires time and patience. It is all about steadily mastering new skills. The same is true when it comes to learning information — preparing for that quiz bowl, say, or studying for a big test.
    As teachers, coaches and parents everywhere like to say: Practice makes perfect.
    Doing something over and over again doesn’t just make it easier. It actually changes the brain. That may not come as a surprise. But exactly how that process happens has long been a mystery. Scientists have known that the brain continues to develop through our teenage years. But these experts used to think that those changes stopped once the brain matured.
    Recent data have been showing that the brain continues to change over the course of our lives. Cells grow. They form connections with new cells. Some stop talking to others. And it’s not just nerve cells that shift and change as we learn. Other brain cells also get into the act.
    Scientists have begun unlocking these secrets of how we learn, not only in huge blocks of tissue, but even within individual cells.


  • The brain is not one big blob of tissue. Just six to seven weeks into the development of a human embryo, the brain starts to form into different parts. Later, these areas will each take on different roles. Consider the prefrontal cortex. It’s the region right behind your forehead. That’s where you solve problems. Other parts of the cortex (the outer layer of the brain) help process sights and sounds. Deep in the brain, the hippocampus helps store memories. It also helps you figure out where things are located around you.
    Scientists can see what part of the brain is active by using functional magnetic resonance imaging, or fMRI. At the heart of every fMRI device is a strong magnet. It allows the device to detect changes in blood flow. Now, when a scientist asks a volunteer to perform a particular task — such as playing a game or learning something new — the machine reveals where blood flow within the brain is highest. That boost in blood flow highlights which cells are busy working.
  • Many brain scientists use fMRI to map brain activity. Others use another type of brain scan, known as positron emission tomography, or PET. Experts have performed dozens of such studies. Each looked at how specific areas of the brain responded to specific tasks.
    Nathan Spreng did something a little different: He decided to study the studies. Spreng is a neuroscientist at Cornell University in Ithaca, N.Y. A neuroscientist studies the brain and nervous system. Spreng wanted to know how the brain changes — how it morphs a little bit — as we learn.
    He teamed up with two other researchers. Together, they analyzed 38 of those earlier studies. Each study had used an fMRI or PET scan to probe which regions of the brain turn on when people learn new tasks.
    Areas that allow people to pay attention became most active as someone began a new task. But those attention areas became less active over time. Meanwhile, areas of the brain linked with daydreaming and mind-wandering became more active as people became more familiar with a task.
    “At the beginning, you require a lot of focused attention,” Spreng says. Learning to swing a bat requires a great deal of focus when you first try to hit a ball. But the more you practice, Spreng says, the less you have to think about what you’re doing.
    Extensive practice can even allow a person to perform a task while thinking about other things — or about nothing at all. A professional pianist, for example, can play a complex piece of music without thinking about which notes to play next. In fact, stopping to think about the task can actually interfere with a flawless performance. This is what musicians, athletes and others often refer to as being “in the zone.”                              Cells that fire together, wire together
  • Spreng’s findings involve the whole brain. However, those changes actually reflect what’s happening at the level of individual cells.
    The brain is made up of billions of nerve cells, called neurons. These cells are chatty. They “talk” to each other, mostly using chemical messengers. Incoming signals cause a listening neuron to fire or send signals of its own. A cell fires when an electrical signal travels through it. The signal moves away from what is called the cell body, down through a long structure called an axon. When the signal reaches the end of the axon, it triggers the release of those chemical messengers. The chemicals then leap across a tiny gap. This triggers the next cell to fire. And on it goes.
    As we learn something new, cells that send and receive information about the task become more and more efficient. It takes less effort for them to signal the next cell about what’s going on. In a sense, the neurons become wired together.
    Spreng detected that wiring. As cells in a brain area related to some task became more efficient, they used less energy to chat. This allowed more neurons in the “daydreaming” region of the brain to rev up their activity.
    Neurons can signal to several neighbors at once. For example, one neuron might transmit information about the location of a baseball pitch that’s flying toward you. Meanwhile, other neurons alert your muscles to get ready to swing the bat. When those neurons fire at the same time, connections between them strengthen. That improves your ability to connect with the ball.                                         Learning while you slumber
  • The brain doesn’t shut down overnight. In fact, catching some zzz’s can dramatically improve learning. That’s because as we sleep, our brains store memories and new information from the previous day. So a poor night’s sleep can hurt our ability to remember new things. Until recently, however, researchers didn’t know why.

A group of scientists at the University of Heidelberg in Germany provided the first clues. Specific cells in the hippocampus — that region involved in storing memories — fired when mice slept, the scientists found. But the cells didn’t fire normally. Instead, electrical signals spontaneously fired near the middle of an axon, then traveled back in the direction of the cell body. In other words, the cells fired in reverse.

  • This boosted learning. It did so by making connections between cells stronger. Again, the action sort of wired together the cells. Research by Olena Bukalo and Doug Fields showed how it happens. They are neuroscientists at the National Institutes of Child Health and Human Development in Bethesda, Md.
    Working with tissue from rat brains, the scientists electrically stimulated nerve axons. Carefully, they stimulated them just in the middle. The electrical signals then traveled in reverse. That is just what the German scientists had seen.
    This reverse signaling made the neuron less sensitive to signals from its neighbors, the experts found. This made it harder for the cell to fire, which gave the neuron a chance to recharge, Bukalo explains. When she then applied electric stimulation near the cell body, the neuron fired. And it did so even more strongly than it had before.
    Cells involved in learning new information are most likely to fire in reverse during sleep, Bukalo says. The next day, they will be wired more tightly to each other. Although scientists don’t know for certain, it is likely that repeated cycles of reverse firing create a strong network of neurons. The neurons relay information faster and more efficiently, just as Spreng found in his study. As a result, those networks reflect an improvement in understanding or physical skill.

                                                  Firing faster

  • Neurons are the best-known cells in the brain. But they are far from the only ones. Another type, called glia, actually makes up a whopping 85 percent of brain cells. For a long time, scientists thought that glia simply held neurons together. (Indeed, “glia” take their name from the Greek word for glue.) But recent research by Fields, Bukalo’s colleague at the National Institutes of Child Health and Human Development, reveals that glial cells also become active during learning.
    One type of glial cell wraps around nerve axons. (Note: Not all axons have this wrapping.) These wrapping cells create what’s known as a myelin sheath. Myelin is made of protein and fatty substances. It insulates the axons. Myelin is a bit like the plastic coating that jackets the copper wires in your home. That insulation prevents electrical signals from inappropriately leaking out of one wire (or axon) and into another.
    In axons, the myelin sheath has a second role: It actually speeds the electrical signals along. That’s because glial cells force a signal to jump from one spot on the axon to the next. As it hops between glial cells, the signal moves faster. It’s kind of like flying from one spot to the next, instead of taking the train.

Fields has found that when new skills are learned, the amount of myelin insulating an axon increases. This happens as the size of individual glial cells increases. New glial cells also may be added to bare axons. These changes improve the ability of a neuron to signal. And that leads to better learning.
A thicker myelin sheath helps improve all types of brainy tasks. These include reading, creating memories, playing a musical instrument and more. A thicker sheath is also linked with better decision-making.
Nerve cells continue to add myelin well into adulthood, as our brains continue to grow and develop. The prefrontal cortex, for example — that area where decisions are made — gains myelin well into a person’s 20s. This may explain why teens don’t always make the best decisions. They’re not finished sheathing their nerve cells. But there is hope. And getting enough sleep certainly can help. Glial cells, like neurons, seem to change most during certain stages of sleep.
Exactly what causes the glial cells to change remains a mystery. Fields and his colleagues are hard at work to figure that out. It’s exciting, he says, to launch into a whole new field of research.

Slow and steady

  • These changes in the brain allow for faster, stronger signaling between neurons as the brain gains new skills. But the best way to speed up those signals is to introduce new information to our noggins — slowly.
    Many students instead try to memorize lots of information the night before a test. Cramming may get them through the test. But the students won’t remember the information for very long, says Hadley Bergstrom. He is a neuroscientist at the National Institutes of Alcohol Abuse and Alcoholism in Rockville, Md.

It’s important to spread out learning over many days, his work shows. That means learning a little bit at a time. Doing so allows links between neurons to steadily strengthen. It also allows glial cells time to better insulate axons.

          Even an “aha!” moment — when something suddenly becomes clear — doesn’t come out of nowhere. Instead, it is the result of a steady accumulation of information. That’s because adding new information opens up memories associated with the task. Once those memory neurons are active, they can form new connections, explains Bergstrom. They also can form stronger connections within an existing network. Over time, your level of understanding increases until you suddenly “get” it.
Like Fields and Bukalo, Bergstrom stresses the importance of sleep in forming the new memories needed to gain knowledge. So the next time you study for a test, start learning new information a few days ahead of time. The night before, give your brain a break and go to bed early. It will allow your brain a chance to cement that new information into its cells. And that should boost your chances of doing well.

                                                            Power Words

  • axon The long, tail-like extension of a neuron that conducts electrical signals away from the cell.
    Cell body The compact section of a neuron (nerve cell) where its nucleus is located.
    cortex The outermost layer of neural tissue of the brain.
    FMRI (short for functional magnetic resonance imaging) A special type of machine used to study brain activity. It uses a strong magnetic field to monitor blood flow in the brain. Tracking the movement of blood can tell researchers which brain regions are active.
    glia Non-nerve cells, these make up 85 percent of the cells in the brain. Some glial cells wrap around axons. This speeds the rate of neural signaling and helps to prevent confusing “cross-talk” between neighboring nerve cells.
    Hippocampus A seahorse-shaped region of the brain. It is thought to be the center of emotion, memory and the involuntary nervous system.
    Myelin (as inmyelin sheath) A layer of fatty cells, called glia, that wraps around nerve-cell axons. The myelin sheath insulates axons, speeding the rate at which signals speed down them. The addition of this sheath is a process known as myelination ormyelinating.
    Neuron (or nerve cell) Any of the impulse-conducting cells that make up the brain, spinal column and nervous system. These specialized cells transmit information to other neurons in the form of electrical signals.
    Neuroscience Science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.
    PET (short for positron emission tomography) A technology that uses radiation to create three-dimensional images of the inside of the body. The individual receives a radioactive “tracer” chemical in the blood that shows up during the scan. As the tracer moves through the body, it will accumulate in certain organs. This allows researchers and doctors to see create X-ray-like details of those organs.
    Prefrontal cortex A region containing some of the brain’s gray matter. Located behind the forehead, it plays a role in making decisions and other complex mental activities, in emotions and in behaviors.
    Like us on facebookFor more such info like our page : unknown science  Like us on facebook

The Microscopic Structures of Dried Human Tears

Do you know this

The Microscopic Structures of Dried Human Tears

In 2010, photographer Rose-Lynn Fisher published a book of remarkable images that captured the honeybee in an entirely new light. By using powerful scanning electron microscopes, She magnified a Bee’s microscopic structure by hundreds or even thousands of times in size, revealing startling, abstract forms that are far too small to see with the naked eye.

Now, as part of a new project called “Topography of tears,” she’s using microscopes to give us an unexpected view of another familiar subject: dried human tears.

Tears of onion

“I started the project about five years ago, during a period of copious tears, amid lots of change and loss—so I had a surplus of raw material,” Fisher says. After the bee project  and one in which she’d looked at a fragment of her own hip bone removed during surgery, she’d come to the realization that “everything we see in our lives is just the tip of the iceberg, visually,” she explains. “So I had this moment where I suddenly thought, ‘I wonder what a tear looks like up close?’”

When she caught one of her own tears on a slide, dried it, and then peered at it through a standard light microscope, “It was really interesting. It looked like an aerial view, almost as if I was looking down at a landscape from a plane,” she says. “Eventually, I started wondering—would a tear of grief look any different than a tear of joy? And how would they compare to, say, an onion tear?”

Tears of ending beginning

This idle musing ended up launching a multi-year photography project in which Fisher collected, examined and photographed more than 100 tears from both herself an a handful of other volunteers, including a newborn baby.


Scientifically, tears are divided into three different types, based on their origin. Both tears of grief and joy are psychic tears, triggered by extreme emotions, whether positive or negative. Basal tears are released continuously in tiny quantities (on average, 0.75 to 1.1 grams over a 24-hour period) to keep the cornea lubricated. Reflex tears are secreted in response to an irritant, like dust, onion vapors or tear gas.

Tears of laughter

Tears of grief

All tears contain a variety of biological substances (including oils, antibodies and enzymes) suspended in salt water, but as Fisher saw, tears from each of the different categories include distinct molecules as well. Emotional tears, for instance, have been found to contain protein-based hormones including the neurotransmitter leucine enkephalin, a natural painkiller that is released when the body is under stress.


Additionally, because the structures seen under the microscope are largely crystallized salt, the circumstances under which the tear dries can lead to radically dissimilar shapes and formations, so two psychic tears with the exact same chemical makeup can look very different up close. “There are so many variables—there’s the chemistry, the viscosity, the setting, the evaporation rate and the settings of the microscope,” Fisher says.

As Fisher pored over the hundreds of dried tears, she began to see even more ways in which they resembled large-scale landscapes, or as she calls them, “aerial views of emotion terrain.”


“It’s amazing to me how the patterns of nature seem so similar, regardless of scale,” she says. “You can look at patterns of erosion that are etched into earth over thousands of years, and somehow they look very similar to the branched crystalline patterns of a dried tear that took less than a moment to form.”

Closely studying tears for so long has made Fisher think of them as far more than a salty liquid we discharge during difficult moments. “Tears are the medium of our most primal language in moments as unrelenting as death, as basic as hunger and as complex as a rite of passage,” she says. “It’s as though each one of our tears carries a microcosm of the collective human experience, like one drop of an ocean.”

Like us on facebookFor more such interesting posts like our page: Unknown scienceUnknown science

Bringing new life to Laser Guide Star

The Lick Observatory’s Laser Guide Star forms a beam of glowing atmospheric sodium ions. This helps astronomers account for distortions caused by the Earth’s atmosphere so they can see further and more clearly into space.

Earlier this year, Lawrence Livermore engineering technical associate Pam Danforth applied 30 years of laser experience to an out-of-this-world problem — bringing new life to the University of California’s
The Lick Observatory’s Laser Guide Star is vital to astronomers because a natural guide star isn’t always near an object they want to observe. By training the guide star beam into the sky near such an object, an artificial guide star of glowing atmospheric sodium ions is created, allowing the laser guide star to function like a natural guide star and provide correct focus for the object they want to observe.

The Laser Guide Star was a spin-off technology from LLNL’s Atomic Vapor Laser Isotope Separation (AVLIS) program, a project Danforth worked on for nearly 20 years. Her specialty was the program’s dye master oscillator. The dye master oscillator provides precise laser frequency and pulse length for the dye amplifiers.

In addition, Danforth was part of the design team for the two Laser Guide Star systems that are used at both the Lick Observatory and Hawaii’s Keck Observatory. She also was part of the team that installed the system at Keck and prepared the system for use by Lick Observatory staff.

“I have always been enthusiastic about helping astronomers see further and more clearly into space. I enjoyed being part of this developmental effort for many years,” Danforth said. “To be able to make a dramatic impact on the world of astronomy was very exciting.”

It was this combined expertise that made Danforth the right person to help bring the Laser Guide Star back to peak operating condition. According to Lick Observatory Superintendent Kostas Chloros, this work was needed as the system’s performance and efficiency had degraded, impacting the research programs that require the use of a laser guide star.

“Pam and the rest of the team are experts on this laser system,” Chloros said. “Their work from over a decade ago produced a very reliable, robust and stable system, which made operations go smoothly over the years. But a good, precise tune-up was due.”

The low power problem was found to originate at the master oscillator and a burned dye cell. When Danforth evaluated the grazing incidence dye master oscillator (GIDMO) she found it had two significant burns. She was able to locate another viable upstream position. This new dye cell position required a major disassembly and realignment of the GIDMO.

Danforth was able to reposition the grating and realign the GIDMO to the peak of the sodium signal. She also identified several external factors contributing to the low power out of the GIDMO and lower conversion efficiency in the amplifiers.

According to Chloros, this work increased the single frequency power out of the master oscillator dramatically, enabling a higher power and a broader pulse to be delivered to the amplifiers. The overall output power of the laser system was 2-3 times higher.

“As a result, the brighter sodium guide star produces a good reference signal for the newly-developed Shane Adaptive Optics system, and it has benefited other research groups and their projects, as well as new instrument development that takes place at Lick,” he said.

The Lick Observatory, situated on the summit of Mount Hamilton, is an astronomical observatory owned and operated by the University of California. It is the world's first permanently occupied mountain-top observatory.

The Lick Observatory, situated on the summit of Mount Hamilton, is an astronomical observatory owned and operated by the University of California. It is the world’s first permanently occupied mountain-top observatory.

Source:Lawrence Livemore National Laboratory

Like us on Facebook     Like us on facebook

Unknown History of Brain Science

         Brain Science is older than you might expect. Of course, many of the first brain theories were wrong, but you might be surprised by the fact that the first known writings about the brain date fback to 4000 BC. Let’s have a quick overview of some of the main historical milestones regarding the Unknown History of Brain Science:

  • Around 4000 BC, the Sumerians wrote a text describing the effects of the ingestion of the ‘poppy’ plant. This is often considered the first known writing on the brain.
  • Back in 2500 BC, the Egyptians believe that the heart is the most important organ of the body and the source of good and evil. During the embalming process, the heart is preserved for mummification while the brain is discarded, since it is considered a minor organ.
  • Around 400 BC, Hippocrates, the father of medicine, discusses epilepsy as a disturbance of the brain. He also considers the brain to be related with sensation and to be the seat of intelligence. Some few years later, Plato teaches that the brain is the seat of mental processes. His disciple Aristoteles on the other hand, believes that the heart is the seat of mental processes. I guess not all geniuses are always right, or might it be that Aristoteles was fascinated by the Egyptian culture?
  • Around 47 AD, the first neurostimulation therapies are undertaken by Scribonius Largus, the court Physician to Roman emperor Claudius. This fact struck me the most, since electricity was not even discovered yet! How the heck did Scribonius manage to apply electrical currents? Well, the solution he found is simple and elegant: using electrical torpedo fish (eels), which he applied on the body of patients to release pain. Cool!!
  • Until around 1500 AD, not much more happens in brain science, since human dissection and anatomy is banned by the Church. In any case, primitive brain surgery is performed by barbers who offer they services to extract the ‘stone of madness’ from the skull of mentally ill patients. I would not go for that surgery…Aren’t barbers meant to shave?
  • During the Renaissance (1400-1600), human dissection starts againand many advances in neuroscience (mostly from an anatomical point of view) are made. A hidden fact from this time is that vivisections are also carried out on death-penalty criminals. Ouch! That must have hurt…
  • In 1791, Luis Galvany publishes a work describing his experiments on electrical stimulation of frog’s nerves. A few years later (1819) Mary Shelley publishes her famous novel ‘Frankenstein‘, which can also be considered a milestone in brain science…fiction.
  • In 1808, Franz Joseph Gall publishes work on phrenology, a pseudoscience stating that different brain functions are located in different places or modules, such as friendship, courage, ambition, etcetera …. He also states that measuring the skull of a subject provides a lot of information about his/her personality. This theory, which was soon abandoned because of lack of scientific rigour, happened to be very influential in neuropsychology. Actually, in modern times it has been discovered that the brain actually does have specialised areas such as the visual cortex and the motor cortex…we can conclude that Mr. Gall had a lucky fluke.
    • In 1848, Phineas Gage, a railroad worker, survives and actually recoveres from an accident in which an iron rod (3.2 diameter and 110 cm long) was driven completely through his head, destroying much of his left frontal lobe. Although little is known about Gage’s life, it seems that his personality changed radically after the accident. Being hard-working, responsible, and “a great favourite” with the men in his charge, after the accident he was fitful, irreverent, indulging at times in the grossest profanity, at times pertinaciously obstinate, yet capricious and vacillating, … This incident showed that behaviour and personality traits are indeed localised in certain areas of the brain.
    • In 1929, Hans Berger records the first human electroencephalogram (EEG). Nowadays EEG is a widely used technique in psychiatric diagnosis and in brain research. What it is less known is that Hans Berger had a great interest in the scientific study of telepathy. It seems that he had a near-death-experience and that his sister, many kilometres away, had a feeling that Hans was in danger. This fact struck Mr. Berger so much that he decided to switch his mathematical/astronomy studies for medicine, with the goal of discovering the physiological basis of “psychic energy”.

    Much more interesting things happened in the 20th century and for sure many important discoveries will be made in the 21st century. Soon I will write about modern discoveries in Brain Science, which are also quite fascinating. As a preview, the discovery of Quantum Physics allowed many important discoveries in Neuroscience…how can this be? I am sure many readers know the answer. For those who don’t, please stay tuned!

  • For more such posts like us on facebook: Like us on facebook