Related topics: brain activity , proceedings of the national academy of sciences , stroke , dopamine , nerve cells
Brain
hideThe brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, balance, taste, and smell.
Brains can be extremely complex. The cerebral cortex of the human brain contains roughly 15-33 billion neurons depending on gender and age, linked with up to 10,000 synaptic connections each. Each cubic millimeter of cerebral cortex contains roughly one billion synapses. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body and target them to specific recipient cells.
The most important biological function of the brain is to generate behaviors that promote the welfare of an animal. Brains control behavior either by activating muscles, or by causing secretion of chemicals such as hormones. Even single-celled organisms may be capable of extracting information from the environment and acting in response to it. Sponges, which lack a central nervous system, are capable of coordinated body contractions and even locomotion. In vertebrates, the spinal cord by itself contains neural circuitry capable of generating reflex responses as well as simple motor patterns such as swimming or walking. However, sophisticated control of behavior on the basis of complex sensory input requires the information-integrating capabilities of a centralized brain.
Despite rapid scientific progress, much about how brains work remains a mystery. The operations of individual neurons and synapses are now understood in considerable detail, but the way they cooperate in ensembles of thousands or millions has been very difficult to decipher. Methods of observation such as EEG recording and functional brain imaging tell us that brain operations are highly organized, but these methods do not have the resolution to reveal the activity of individual neurons.
For more information about Brain, read the full article at
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News tagged with brain
How to read brain activity?
Medicine & Health / Neuroscience
Dec 04, 2009 |
4 / 5 (6) |
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(PhysOrg.com) -- For the very first time, scientists show what EEG can really tell us about how the brain functions.
Mathematical model of a simple circuit in a chicken brain raises fundamental questions
Dec 01, 2009 |
4.8 / 5 (26) |
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(PhysOrg.com) -- The Web site Neuroanthropology asks visitors to complete this quote, "One of the difficulties in understanding the brain is ...". In addition to the typical facetious remarks, such as "so ...
Tumor-attacking virus strikes with 'one-two punch'
Dec 01, 2009 |
5 / 5 (6) |
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Ohio State University cancer researchers have developed a tumor-attacking virus that both kills brain-tumor cells and blocks the growth of new tumor blood vessels.
Study shows new brain connections form rapidly during motor learning
Medicine & Health / Neuroscience
Nov 29, 2009 |
4.9 / 5 (7) |
0
(PhysOrg.com) -- New connections begin to form between brain cells almost immediately as animals learn a new task, according to a study published this week in Nature. Led by researchers at the University of Cal ...
Intel wants a chip implant in your brain
Nov 23, 2009 |
4.4 / 5 (35) |
49
(PhysOrg.com) -- Computer chip maker Intel wants to implant a brain-sensing chip directly into the brains of its customers to allow them to operate computers and other devices without moving a muscle.
Schizophrenia gene's role may be broader, more potent, than thought
Nov 19, 2009 |
5 / 5 (1) |
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(PhysOrg.com) -- UCSF scientists studying nerve cells in fruit flies have uncovered a new function for a gene whose human equivalent may play a critical role in schizophrenia.
New study shows brain's ability to reorganize
Medicine & Health / Neuroscience
Nov 18, 2009 |
4.6 / 5 (11) |
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(PhysOrg.com) -- Visually impaired people appear to be fearless, navigating busy sidewalks and crosswalks, safely finding their way using nothing more than a cane as a guide. The reason they can do this, researchers suggest, ...
Computer Based on Insights From The Brain Moves Closer to Reality
Technology / Computer Sciences
Nov 18, 2009 |
4.6 / 5 (24) |
4
(PhysOrg.com) -- Today at SC 09, the supercomputing conference, IBM announced significant progress toward creating a computer system that simulates and emulates the brain's abilities for sensation, perception, ...
Bigger not necessarily better, when it comes to brains
Nov 17, 2009 |
4.5 / 5 (19) |
12
(PhysOrg.com) -- Tiny insects could be as intelligent as much bigger animals, despite only having a brain the size of a pinhead, say scientists at Queen Mary, University of London.
Dopamine enhances expectation of pleasure in humans
Medicine & Health / Neuroscience
Nov 12, 2009 |
4.2 / 5 (10) |
0
(PhysOrg.com) -- Enhancing the effects of the brain chemical dopamine influences how people make life choices by affecting expectations of pleasure, according to new research from the UCL Institute of Neurology.
Why can't chimps speak? Study links evolution of single gene to human capacity for language
Nov 11, 2009 |
3.9 / 5 (15) |
3
(PhysOrg.com) -- If humans are genetically related to chimps, why did our brains develop the innate ability for language and speech while theirs did not?
Words, gestures are translated by same brain regions, says new research
Medicine & Health / Neuroscience
Nov 09, 2009 |
4.6 / 5 (5) |
0
Your ability to make sense of Groucho's words and Harpo's pantomimes in an old Marx Brothers movie takes place in the same regions of your brain, says new research funded by the National Institute on Deafness and Other Communication ...
WHO study suggests link between cell phones and tumors
Oct 27, 2009 |
4.2 / 5 (23) |
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(PhysOrg.com) -- Preliminary results of an International investigation by the World Health Organization (WHO) suggest there may be a "significantly increased risk" of some types of brain tumors after use of ...
Manipulating brain inflammation may help clear brain of amyloid plaques
Medicine & Health / Neuroscience
Oct 22, 2009 |
4.8 / 5 (12) |
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In a surprising reversal of long-standing scientific belief, researchers at the Mayo Clinic campus in Florida have discovered that inflammation in the brain is not the trigger that leads to buildup of amyloid deposits and ...
You can control your Marilyn Monroe neuron
Medicine & Health / Neuroscience
Oct 22, 2009 |
4.7 / 5 (26) |
12
(PhysOrg.com) -- In a scientific first, researchers have been able to demonstrate the ability of humans to control the activity of individual brain cells.
