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
Intel wants a chip implant in your brain
Nov 23, 2009 |
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(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 |
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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 |
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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) |
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(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 |
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(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 |
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(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 |
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(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 |
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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 ...
Study sheds light on brain's fear processing center
Nov 25, 2009 |
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Breathing carbon dioxide can trigger panic attacks, but the biological reason for this effect has not been understood. A new study by University of Iowa researchers shows that carbon dioxide increases brain acidity, which ...
Two molecules affecting brain plasticity
Medicine & Health / Neuroscience
Nov 25, 2009 |
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(PhysOrg.com) -- You wouldn't want a car with no brakes. It turns out that the developing brain needs them, too.
fMRI scans used in murder trial sentencing
Nov 25, 2009 |
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(PhysOrg.com) -- Functional Magnetic Resonance Imaging (fMRI) scans have been used, possibly for the first time, in the sentencing phase of a murder trial in Chicago in the US.
Road rage: Fuel vapor heightens aggression
Nov 24, 2009 |
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Outrageous prices may not be the only thing causing anger at the petrol pumps. A new study, published in the open access journal BMC Physiology, has shown that rats exposed to fumes from leaded and unleaded gasoline become ...
Measured -- The time it takes us to find the words we need
Medicine & Health / Psychology & Psychiatry
Nov 23, 2009 |
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(PhysOrg.com) -- The time it takes for our brains to search for and retrieve the word we want to say has been measured for the first time. The discovery is reported in a paper published in the Proceedings of the National Ac ...
Upending textbook science on Alzheimer's disease
Medicine & Health / Neuroscience
Nov 23, 2009 |
5 / 5 (6) |
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Alzheimer's disease is caused by the build-up of a brain peptide called amyloid-beta. That's why eliminating the protein has been the focus of almost all drug research pursuing a cure for the devastating neurodegenerative ...
New discovery about the formation of new brain cells
Nov 23, 2009 |
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The generation of new nerve cells in the brain is regulated by a peptide known as C3a, which directly affects the stem cells' maturation into nerve cells and is also important for the migration of new nerve cells through ...
