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
The thalamus, middleman of the brain, becomes a sensory conductor
Medicine & Health / Neuroscience
Dec 07, 2009 |
4.2 / 5 (5) |
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Two new studies show that the thalamus--the small central brain structure often characterized as a mere pit-stop for sensory information on its way to the cortex--is heavily involved in sensory processing, and is an important ...
Researchers show brain waves can 'write' on a computer in early tests
Dec 07, 2009 |
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Neuroscientists at the Mayo Clinic campus in Jacksonville, Fla., have demonstrated how brain waves can be used to type alphanumerical characters on a computer screen. By merely focusing on the "q" in a matrix of letters, ...
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.
Nerve-cell transplants help brain-damaged rats fully recover lost ability to learn
Medicine & Health / Neuroscience
Dec 09, 2009 |
5 / 5 (4) |
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Nerve cells transplanted into brain-damaged rats helped them to fully recover their ability to learn and remember, probably by promoting nurturing, protective growth factors, according to a new study.
Brain activity exposes those who break promises
Medicine & Health / Neuroscience
Dec 09, 2009 |
2 / 5 (1) |
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Scientists from the University of Zurich have discovered the physiological mechanisms in the brain that underlie broken promises. Patterns of brain activity even enable predicting whether someone will break a promise. The ...
Scientists discover first evidence of brain rewiring in children
Medicine & Health / Neuroscience
Dec 09, 2009 |
5 / 5 (6) |
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Carnegie Mellon University scientists Timothy Keller and Marcel Just have uncovered the first evidence that intensive instruction to improve reading skills in young children causes the brain to physically ...
Epilepsy Patients Are Given New Hope With Brain Implant
Medicine & Health / Neuroscience
Dec 09, 2009 |
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(PhysOrg.com) -- A startup company, Neuropace in Mountain View Ca., has developed a device that offers new hope for epilepsy patients. The device is designed to neutralize the abnormal electrical activity ...
Family's inherited condition links prion diseases, Alzheimer's
Medicine & Health / Neuroscience
Dec 09, 2009 |
4.5 / 5 (2) |
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(PhysOrg.com) -- A laboratory connection between Alzheimer's disease and brain-wasting diseases such as the human form of mad cow disease has moved into the clinic for what is believed to be the first time, manifesting itself ...
Cut out the (estrogen) middleman
Medicine & Health / Neuroscience
Dec 08, 2009 |
not rated yet |
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Estrogen seems to act like a middleman in its positive effect on the brain, raising the possibility that future drugs may bypass the carcinogenic hormone altogether while reaping its benefits.
With amino acid diet, mice improve after brain injury
Dec 07, 2009 |
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Neurology researchers have shown that feeding amino acids to brain-injured animals restores their cognitive abilities and may set the stage for the first effective treatment for cognitive impairments suffered by people with ...
Antidepressant Can Change Patient's Personality
Medicine & Health / Psychology & Psychiatry
Dec 07, 2009 |
4.3 / 5 (12) |
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(PhysOrg.com) -- The nation is still debating the effects of antidepressant medications on brain chemistry almost 20 years after publication of the best-seller "Listening to Prozac." Though selective serotonin reuptake inhibitors ...
Extended youthfulness as a prevention for Alzheimer's disease
23 hours ago |
4 / 5 (1) |
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Therapies that can keep us younger longer might also push back the clock on Alzheimer's disease, suggests a new study of mice in the December 11th issue of the journal Cell, a Cell Press publication.
Pathological gambling may be successfully treated with medications for substance addiction
Medicine & Health / Psychology & Psychiatry
Dec 10, 2009 |
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Pathological gambling can be successfully treated with medications that decrease urges and increase inhibitions, according to researchers at the annual meeting of the American College of Neuropsychopharmacology (ACNP). Researchers ...
Irregular arm swing may point to Parkinson's disease
Dec 10, 2009 |
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Irregular arm swings while walking could be an early sign of Parkinson's disease, according to neurologists who believe early detection may help physicians apply treatments to slow further brain cell damage until strategies ...
Brain imaging shows kids' PTSD symptoms linked to poor hippocampus function
Medicine & Health / Psychology & Psychiatry
Dec 08, 2009 |
4.5 / 5 (2) |
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Psychological trauma leaves a trail of damage in a child's brain, say scientists at the Stanford University School of Medicine and Lucile Packard Children's Hospital. Their new study gives the first direct evidence that children ...
