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Matter Brain Throughout History the human brain has been very successful in concealing its role. Everything from ancient Egyptians before Aristotle, underestimated the significance of the mysterious substances between our ears. The famous anatomist Galen attributed the role of the brain in controlling the movement and speech, but even he dismissed side gray and white matter, deciding that filled with liquid the cameras inside the brain do most of its work.
Human brains are big …
The brain of an average adult weighs about 1.3-1.4 kilograms. Some neurosurgeons describe the texture of the living brain as something like toothpaste, but according to neurosurgeon Catherine Firlik, a more suitable analogy can be found in your local health food store.
“The brain doesn’t spread like toothpaste. And it doesn’t stick to your fingers like her, “writes Firlik in his memoirs,” Another Day in the Frontal Lobe: A Brain Surgeon Exposes Life on the Inside ” (Random House, 2006). “Tofu is a soft variety if you familiar with tofu – may be a more appropriate comparison. ”
If you are not fascinated by this description, think about it: About 80% the contents of your cranium make up the brain, while approximately equal amounts of blood and cerebrospinal fluid occupy the rest of the space. If you mix this whole brain, blood and fluid, they will be approximately 1.7 liters, then eat a little less than you need to fill a 2 liter bottle cola.
… but they are decreasing
But don’t be too proud of this whole brain-sized story a bottle of cola. People 5,000 years ago had brains even greater size.
“From archaeological evidence, almost anywhere we can measure – in Europe, China, South Africa, Australia – we know that the brain decreased by about 150 cubic centimeters from the average of 1350 cubic centimeters. it approximately 10%, “the paleoanthropologist told LiveScience University of Wisconsin John Hawks in 2009.
Researchers don’t know why brains are shrinking, but some theories believe that they evolve into more efficient ones. Other believe that our skulls are reduced due to a diet consisting of more easily chewed food, resulting in large, strong jaws are no longer required.
Whatever the reason, brain size does not directly correlate with intelligence, so that we have no evidence that the ancient man was smarter than modern man.
Our brains consume energy
The brain of modern man is a black hole that absorbs energy. An organ, which is about 2% of body weight, consumes about 20% blood oxygen and 25% glucose circulating in our bloodstream, according to the American College of Neuropsychopharmacology.
These energy needs spurred debate among anthropologists about what generally triggered the evolution of big brains. Many scientists consider the case to be meat, citing evidence of distribution hunting among our early ancestors. Meat is unreliable however food source, other researchers say. Study, published in 2007 by the National Academy of Science, says that modern chimpanzees know how to dig rich in the savannah calorie root vegetables. Perhaps our ancestors did the same nourishing the power of your brain with vegetables.
And as for why our brains were swollen in size, There are three main theories: climate change, environmental conditions, and social competition.
Wrinkles make us smarter
What is the secret of the mind of our species? The answer may be wrinkles. The surface of the human brain is streaked with deep folds, with valleys called sulci, and ridges, which are called “gyri”. This surface is called bark. brain and consists of approximately 100 billion neurons, or nerve cells.
The folded surface allows the brain to fit more into a smaller volume – and therefore accumulate more “computing power”. Our primacy relatives show varying degrees of folding. brain, as well as other intelligent creatures – for example, elephants. AND incidentally, a study by a neuroscientist Lori Marino from Emory University showed that dolphins have even more pronounced folds in the cortex brain than people.
Most of the cells in our brain are not neurons
The old belief that we use only 10% of our brain is wrong, but now we know that neurons make up only 10% of the brain.
The remaining 90%, which is about half the mass of the brain, called “glia”, which in Greek means “glue”. Neuroscientists used to thinking that glia is just a sticky substance, which holds neurons together. But recent studies have shown that the role of glia is much broader. Journal Article “Current Opinions in Neurobiology” in 2005, pointed to the true the role of these invisible cells, whose activity extends from disposal of excess neurotransmitters to ensure immune protection and stimulation of synapse growth. As it turns out, the silent majority seems not to be so silent.
The brain is a closed club
Like bouncers in a nightclub, groups of cells in the circulatory the brain system, called the blood-brain barrier, allow only a small number of molecules penetrate the inner nervous sanctuary systems to the brain. The capillaries that feed the brain are tightly lined lying cells that prevent the penetration of large molecules. Special proteins in the barrier transport the necessary nutrients inside the brain. Only the elite are allowed to penetrate here.
The blood-brain barrier protects our brain, but it also prevents the penetration of important drugs. Doctors trying cure a brain tumor, can use substances that open gaps between cells, but it leaves the brain temporarily vulnerable to infections. One of the new ways to deliver drugs beyond the barrier may be nanotechnology. Study published in magazine “Cancer Research” in 2009, showed that specifically engineered nanoparticles can penetrate the barrier and attach to tumor tissue. In the future, sharing nanoparticles and chemotherapy may be one way to deal with tumors.
The brain begins with a tube
The foundation for the brain is laid very early. In three weeks after conception, a layer of embryonic cells called neuro plate, folds and forms a neurotube. This fabric subsequently become the central nervous system.
The neurotube grows and differentiates throughout the first trimester. (When cells differentiate, they develop into different tissues from which different parts of the body will be formed.) Neurons and glia begin to form in the second trimester. Bark the brain is formed even later. In the third trimester, starting at 26 weeks, the convolutions in the cortex deepen, and the fetal brain begins to resemble on the brain that newborns have.
Teen brains are not completely formed
Parents of difficult teens can rejoice, or at least least relax: the behavior of such adolescents is partially dependent on vagaries of brain development.
The development of gray matter peaks at the time of sexual maturing, and then inhibited during adolescence, showing the greatest developmental effect in the frontal lobes of the brain, Responsible for judgment and decision making.
Study published in the journal “Child Development” in 2005 showed that the parts of our brain that are responsible for multitasking, fully formed only by 16-17 years. A study presented at the 2006 Festival of Science showed that adolescents have a science-based justification for their egocentrism. Pondering an action that affects others, teens are much less likely than adults to use median prefrontal cortex, area associated with empathy and guilt. And so it goes on until about 20 age.
Brains never stop changing
Science once claimed that when our brain reached maturity loses the ability to form new synapses. This ability which was called “ductility” was thought to be limited the age of infancy and childhood.
Misconception. 2007 Patient Study who had a stroke, found that her brain had adapted to damage to the optical nerves, taking similar information from other nerve fibers. This was followed by several studies, which showed that adult mice are able to form new neurons. Later studies have discovered even more evidence that human neurons are capable of forming new synapses in adulthood; at the same time, studies of meditation showed that intense mental training can change and structure and function of the brain.
Women are still not from Venus
Popular culture tells us that the brains of men and women just different. This is true in the sense that male and female hormones different effects on brain development, and visual studies showed differences in how men and women feel pain, make social decisions and manage stress. Limit to whose differences are genetically determined and not formed experience – still unknown.
But for the most part, the brains of men and women are the same. Analysis of Gender Differences by American Journal Psychologist “in 2005, showed that in 78% of cases gender differences described in other studies, the effect of gender on the behavior ranged from negligible to zero. A recent research has exposed the myth of ability difference different sexes. Study published in the journal Psychological Bulletin “in January 2010, studied nearly half a million boys and girls from 69 countries and found no differences in their math abilities. Focusing on our differences can give A good title for a book, but in neurobiology, nothing is so simple.
Did you know that …
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Bees brain surpasses computer
A new study says that bees can solve complex mathematical problems for which computer would take days.
Insects can choose the shortest route between flowers, randomly detected, effectively solving the problem “traveling advertising agent,” researchers say University of London.
The salesman’s puzzling task is to find the optimal path that would allow him to drive all the intended them plots. Computers solve this problem by comparing lengths. all possible routes, and choosing which one the shortest.
Bees manage to achieve the same result when using brain the size of a poppy seed.
Dr. Nigel Reign of the School of Life Sciences at Royal Holloway says: prey bees solve the traveler’s difficult problems a salesman every day. They fly to the flowers that are in different places, and since they spend a lot of energy not flying, they find the shortest routes for their flights. ”
Using computer-controlled artificial flowers for checking the behavior of bees, she tried to find out if there will be bees fly along a simple route, which is determined by the order finding flowers, or will find the shortest path.
After exploring the location of the flowers, the bees quickly find the shortest ways to save time and energy.
Study to be published in journal this week American Naturalist, has a bottom line for the world of people. Modern life depends on work networks such as transport traffic, internet information and interaction chains in business.
“Despite its tiny brain, the bees in their behavior capable of delivering outstanding results, “says Raine.” And to us you should understand how they manage to solve such problems without help computer. ”