10 Facts about our Brain, You never heard of
10 Ultimate facts about your brain
Amazing Brain Facts
These are the brain facts that you don’t even find then in
google search.
Brain
matter
Throughout history, the human brain has been remarkably good
at dismissing itself. Everyone from ancient Egyptians to Aristotle has
downplayed the role of the mysterious stuff between our ears. Famed anatomist
Galen gave the brain credit as commander of movement and speech, but even he
brushed aside the white and gray matter, figuring the fluid-filled ventricles
inside the brain did most of the work.
1. Women
aren't from Venus after all
Popular culture tells us that women and men's brains are
just different. It's true that male and female hormones affect brain
development differently, and imaging studies have found brain differences in
the ways women and men feel pain, make social decisions and cope with stress.
The extent to which these differences are genetic versus shaped by experience —
the old nature-versus-nurture debate — is unknown.
But for the most part, male and female brains (and
brainpower) are similar. A 2005 American Psychologist analysis of research on
gender differences found that in 78 percent of gender differences reported in
other studies, the effect of gender on the behavior was in the small or
close-to-zero range. And recent studies have debunked myths about the genders'
divergent abilities. A study published in the January 2010 Psychological
Bulletin looked at almost half a million boys and girls from 69 countries and
found no overall gap in math ability. Focusing on our differences may make for
catchy book titles, but in neuroscience, nothing is ever that simple.
2. Brains
never stop changing
Scientific wisdom once held that once you hit adulthood,
your brain lost all ability to form new neural connections. This ability,
called plasticity, was thought to be confined to infancy and childhood.
Wrong. A 2007 study on a stroke patient found that her brain
had adapted to the damage to nerves carrying visual information by pulling
similar information from other nerves. This followed several studies showing
that adult mice could form new neurons. Later studies found more evidence of
human neurons making new connections into adulthood; meanwhile, research on
meditation showed that intense mental training can change both the structure
and function of the brain.
3. Teen
brains aren't fully formed
Parents of stubborn teenagers rejoice, or at least relax:
That adolescent attitude stems, in part, from the vagaries of brain
development.
The gray matter of the brain peaks just before puberty and
is pruned back down throughout adolescence, with some of the most dramatic
development happening in the frontal lobes, the seat of judgment and
decision-making.
A 2005 study published in the journal Child Development
found that the parts of the brain responsible for multitasking don't fully
mature until we're 16 or 17 years old. And research presented at the BA
Festival of Science in 2006 revealed that teens also have a neural excuse for
self-centeredness. When considering an action that would affect others, teens
were less likely than adults to use the medial prefrontal cortex, an area
associated with empathy and guilt. Teens learn empathy by practicing
socializing, the researchers said. So much for grounding them until they're 20.
4. The
brain starts as a tube
The foundation for the brain is set early. Three weeks after
conception, a sheet of embryonic cells called the neural plate folds and fuses
into the neural tube. This tissue will become the central nervous system.
The neural tube grows and differentiates throughout the
first trimester. (When cells differentiate they specialize into various tissues
needed to create body parts.) It isn't until the second trimester that glia and
neurons begin to form. The brain doesn't wrinkle up until even later. At 24
weeks, magnetic resonance imaging shows just a few nascent grooves in the
otherwise smooth surface of the fetal brain, according to a 2000 study in the
journal Radiology. As the third trimester begins in week 26, the grooves deepen
and the brain begins to look more like that of a newborn.
5. The
brain is an exclusive club
Like bouncers at a night club, an assembly of cells in the
brain's blood system, called the blood-brain barrier, lets only a few molecules
into the nervous system's inner sanctum – the brain. The capillaries that feed
the brain are lined with tightly bound cells, which keep out large molecules.
Special proteins in the barrier transport necessary nutrients and substances
into the brain. Only an elite few make it through.
The blood-brain barrier protects the brain, but it can also
keep out lifesaving medications. Physicians trying to treat brain tumors can
use drugs to open the junctions between cells, but that leaves the brain
temporarily vulnerable to infection. One new way to sneak meds past the barrier
might be nanotechnology. A 2009 study published in the journal Cancer Research
showed that specially-engineered nanoparticles can cross the barrier and attach
to tumor tissue. In the future, combining nanoparticles with chemotherapy drugs
could be one way to target tumors.
6. Most
of our brain cells aren't neurons
The old saw that we use just 10 percent of our brainpower
isn't true, but we now know that neurons make up just 10 percent of our brain
cells.
The other 90 percent, which account for about half the
brain's weight, are called glia, which means "glue" in Greek.
Neuroscientists used to think glia were simply the sticky stuff that holds
neurons together. But recent research has shown glia to be much more. A 2005
paper in the journal Current Opinions in Neurobiology laid out the roles of
these unsung cells, which range from mopping up excess neurotransmitters to
providing immune protection to actually promoting and modulating synapse growth
and function. (Synapses are the connections between neurons.) It turns out the
silent majority isn't so silent after all.
7. Wrinkles
make us smart
What's the secret to our species' smarts? The answer may be
wrinkles. The surface of the human brain is convoluted by deep fissures,
smaller grooves called sulci, and ridges called gyri. This surface is called
the cerebral cortex and is home to about 100 billion neurons, or nerve cells.
The folded, meandering surface allows the brain to pack in
more surface area — and thus, more processing power — into the limited confines
of the skull. Our primate relatives show varying degrees of convolution in
their brains, as do other intelligent creatures like elephants. In fact,
research done by Emory University neuroscientist Lori Marino has found that
dolphins have even more pronounced brain wrinkles than humans.
8. Our
brains burn through energy
The modern brain is an energy hog. The organ accounts for
about 2 percent of body weight, but it uses about 20 percent of the oxygen in
our blood and 25 percent of the glucose (sugars) circulating in our
bloodstream, according to the American College of Neuropsychopharmacology.
These energy requirements have spurred a debate among
anthropologists about what fueled the evolution of big brains in the first
place. Many researchers credit meat, citing evidence of hunting in our early
ancestors. But meat would have been an unreliable food source, say other
scientists. A 2007 study published in the Proceedings of the National Academy
of Science found that modern-day chimps know how to dig for calorie-rich tubers
on the savanna. Perhaps our ancestors did the same, boosting their brainpower
with veggies.
As for what motivated the brain to balloon in size, there
are three major hypotheses: climate change, the demands of ecology, and social
competition.
9. Human
brains are big...
The average adult brain weighs just under 3 pounds (between
1.3 and 1.4 kilograms). Some neurosurgeons describe the texture of a living
brain as that of toothpaste, but according to neurosurgeon Katrina Firlik, a
better analogy can be found in the local health-food store.
"[The brain] doesn't spread like toothpaste. It doesn't
adhere to your fingers the way toothpaste does," Firlik writes in her
memoir, "Another Day in the Frontal Lobe: A Brain Surgeon Exposes Life on
the Inside" (Random House, 2006). "Tofu — the soft variety, if you
know tofu — may be a more accurate comparison."
If you aren't charmed by that description, consider this:
About 80 percent of the contents of your cranium is brain, while equal amounts
of blood and cerebrospinal fluid, the clear liquid that buffers neural tissue,
make up the rest. If you were to blend up all of that brain, blood and fluid,
it would come to about 1.7 liters, or not quite enough to fill a 2-liter soda
bottle.
10. But
they're getting smaller
Don't get too cocky about your soda-bottle-sized brain.
Humans 5,000 years ago had brains that were even larger.
"We do know from archaeological data that pretty much
everywhere we can measure — Europe, China, South Africa, Australia — that
brains have shrunk about 9 cubic inches (150 cubic centimeters), from an
average of about 82 in3 (1,350 cm3). That's roughly 10 percent," University
of Wisconsin at Madison paleoanthropologist John Hawks told LiveScience in
2009.
Researchers don't know why brains might be shrinking, but
some theorize that they're evolving to be more efficient. Others think our
skulls are getting smaller because our diets include more easily chewable foods
and so large, strong jaws are no longer required.
Whatever the reason, brain size doesn't directly correlate
with intellect, so there's no evidence that ancient man was brainier than
humans of today.
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