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
Developmental delay could stem from nicotinic receptor deletion
Nov 08, 2009 |
4.7 / 5 (3) |
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The loss of a gene through deletion of genetic material on chromosome 15 is associated with significant abnormalities in learning and behavior, said a consortium of researchers led by Baylor College of Medicine in a report ...
Psychiatric impact of torture could be amplified by head injury
Medicine & Health / Psychology & Psychiatry
Nov 06, 2009 |
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Depression and other emotional symptoms in survivors of torture and other traumatic experiences may be exacerbated by the effects of head injuries, according to a study from the Harvard Program in Refugee Trauma (HPRT), based ...
Turn On, Tune In, Develop? Researchers Examine How Brain Benefits From Musical Training
Medicine & Health / Neuroscience
Nov 06, 2009 |
5 / 5 (11) |
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For most people music is an enjoyable, although momentary, form of entertainment. But for those who seriously practiced a musical instrument when they were young, perhaps when they played in a school orchestra ...
Gene therapy technique slows ALD brain disease
Nov 05, 2009 |
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A strategy that combines gene therapy with blood stem cell therapy may be a useful tool for treating a fatal brain disease, French researchers have found. These findings appear in the 6 November 2009 issue ...
Crossing the line: how aggressive cells invade the brain (w/ Video)
Nov 05, 2009 |
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In diseases such as multiple sclerosis, cells of the immune system infiltrate the brain tissue, where they cause immense damage. For many years, it was an enigma as to how these cells can escape from the bloodstream. ...
Study shows neural stem cells in mice affected by gene associated with longevity
Nov 05, 2009 |
3 / 5 (2) |
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(PhysOrg.com) -- A gene associated with longevity in roundworms and humans has been shown to affect the function of stem cells that generate new neurons in the adult brain, according to researchers at the Stanford University ...
Early scents really do get 'etched' in the brain
Medicine & Health / Neuroscience
Nov 05, 2009 |
3 / 5 (2) |
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Common experience tells us that particular scents of childhood can leave quite an impression, for better or for worse. Now, researchers reporting the results of a brain imaging study online on November 5th ...
Baby Einstein Controversy: Professor Offers Healthy Language Learning Alternatives for Young Children
Medicine & Health / Psychology & Psychiatry
Nov 05, 2009 |
4.5 / 5 (2) |
1
(PhysOrg.com) -- Baby Einstein videos have become a staple in many American households until recently when the Walt Disney Company decided to refund the product, acknowledging that these ever-popular videos were not intended ...
Miracle Aussie baby beats rare condition in world first
Medicine & Health / Medications
Nov 05, 2009 |
4.9 / 5 (7) |
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A "miracle" Australian baby has become the first person cured of a rare and deadly brain-melting condition after doctors gambled on an experimental drug tested only on mice, they said Thursday.
UCI robot to aid brain research
Nov 04, 2009 |
5 / 5 (1) |
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(PhysOrg.com) -- A robot powered by a computerized model of a rodent brain will help researchers from UC Irvine and UC San Diego understand how people recognize and adapt to change.
Metal Deficit in Mouse Brain Plaques Guides Direction of Human Alzheimer's Disease Research
Medicine & Health / Neuroscience
Nov 04, 2009 |
4.5 / 5 (2) |
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(PhysOrg.com) -- Minuscule plaques in the brains of mice with Alzheimer's disease contain much less metal than the brains of affected humans, according to a study conducted at the NSLS. This surprising finding ...
A vast right arm conspiracy? Study suggests handedness may effect body perception
Medicine & Health / Psychology & Psychiatry
Nov 04, 2009 |
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There are areas in the brain devoted to our arms, legs, and various parts of our bodies. The way these areas are distributed throughout the brain are known as "body maps" and there are some significant differences in these ...
Hybrid molecules show promise for exploring, treating Alzheimer's
Nov 04, 2009 |
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One of the many mysteries of Alzheimer's disease is how protein-like snippets called amyloid-beta peptides, which clump together to form plaques in the brain, may cause cell death, leading to the disease's devastating symptoms ...
What is unique in the brain of an Arabic speaker?
Medicine & Health / Neuroscience
Nov 04, 2009 |
4.3 / 5 (11) |
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Literary Arabic is expressed in the brain of an Arabic speaker as a second language and not as a native language. This has been shown in a new study by Dr. Raphiq Ibrahim of the Edmond J. Safra Brain Research Center for the ...
Less brain swelling occurs with multiple sessions of SRS for common brain tumor
Nov 04, 2009 |
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Treating a common brain tumor with multiple sessions of radiation appears to result in less brain swelling than treating the tumor once with a high dose of radiation, say researchers from the Lombardi Comprehensive Cancer ...
