Related topics: neurons , proceedings of the national academy of sciences , brain cells , brain activity , 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
Sporting Prowess Through Brain Power
Medicine & Health / Neuroscience
19 hours ago |
4.5 / 5 (2) |
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A study conducted by scientists at Brunel University and at the University of Hong Kong has found that expert sportsmen are quicker to observe and react to their opponents' moves than novice players, exhibiting enhanced activation ...
Ethics debate over blood from newborn safety tests
Feb 08, 2010 |
5 / 5 (1) |
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(AP) -- A critical safety net for babies - that heelprick of blood taken from every newborn - is facing an ethics attack.
Yale Scientists Shed Colorful Light On Novel Proteins
Feb 08, 2010 |
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(PhysOrg.com) -- A Yale School of Medicine neuroscientist investigating how viruses can be used to attack brain cancers has developed a new method to generate novel, color-coded proteins that can be used by ...
Scientists discover novel materials approach to fighting cancer (w/ Video)
Nanotechnology / Bio & Medicine
Feb 08, 2010 |
4.7 / 5 (6) |
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(PhysOrg.com) -- Scientists from the U.S. Department of Energy's Argonne National Laboratory and the University of Chicago Medical Center are shaking up the world of materials science and cancer research on the cover of the ...
Mediterranean diet may lower risk of brain damage that causes thinking problems
Medicine & Health / Neuroscience
Feb 08, 2010 |
5 / 5 (1) |
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A Mediterranean diet may help people avoid the small areas of brain damage that can lead to problems with thinking and memory, according to a study released today that will be presented at the American Academy of Neurology's ...
Neuroscientists discover brain area responsible for fear of losing money
Medicine & Health / Neuroscience
Feb 08, 2010 |
3.4 / 5 (7) |
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Neuroscientists at the California Institute of Technology and their colleagues have tied the human aversion to losing money to a specific structure in the brain-the amygdala.
Metabolite common among cancers
Feb 08, 2010 |
5 / 5 (1) |
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A study published online on February 8 in the Journal of Experimental Medicine reports that several distinct mutations found in a subset of patients with acute myelogenous leukemia (AML) result in excess production of the ...
Blacks with MS have more severe symptoms, decline faster than whites
Medicine & Health / Neuroscience
Feb 05, 2010 |
not rated yet |
1
Fewer African Americans than Caucasians develop multiple sclerosis (MS), statistics show, but their disease progresses more rapidly, and they don't respond as well to therapies, a new study by neurology researchers at the ...
Length of time in institutional care may influence children's learning
Feb 05, 2010 |
5 / 5 (1) |
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The amount of time children spend in institutional care may affect how their brains develop.
Australian researchers put paid to "baby brain" myth
Medicine & Health / Psychology & Psychiatry
Feb 05, 2010 |
4.5 / 5 (2) |
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Australian researchers said on Friday they had debunked the myth that a women's ability to think was impaired by pregnancy and mothering a newborn -- a condition commonly referred to as "baby brain".
Prion leaves lasting mark on memory
Medicine & Health / Neuroscience
Feb 04, 2010 |
4 / 5 (2) |
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Prions are a special class of proteins best known as the source for mad cow and other neurodegenerative diseases. Despite this negative reputation, according to a new report in the February 5th issue of the journal Cell a prio ...
New study maps the effects of acupuncture on the brain
Medicine & Health / Neuroscience
Feb 04, 2010 |
5 / 5 (4) |
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Important new research about the effects of acupuncture on the brain may provide an understanding of the complex mechanisms of acupuncture and could lead to a wider acceptability of the treatment.
Melatonin precursor stimulates growth factor circuits in brain
Feb 04, 2010 |
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Scientists at Emory University School of Medicine have discovered unexpected properties for a precursor to melatonin, the hormone that regulates sleep cycles.
Patient presumed vegetative communicates via brain scan: study
Medicine & Health / Neuroscience
Feb 03, 2010 |
5 / 5 (26) |
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(AP) -- Scientists have detected glimmers of awareness in some vegetative brain-injury patients and have even communicated with one of them - findings that push the boundaries of how to assess and care for ...
New method for treating stress
Feb 03, 2010 |
3.3 / 5 (3) |
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(PhysOrg.com) -- A new analysis of the way the body responds to stress suggests that administering constant high levels of drugs is not the best way to treat this condition. A better way might be to design drugs that follow ...
