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
Funeral industry workers exposed to formaldehyde face higher risk of leukemia
1hour ago |
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Long durations of exposure to formaldehyde used for embalming in the funeral industry were associated with an increased risk of death from myeloid leukemia, according to a new study published online November 20 in the Journal of ...
Study uses brain scans to discover how children 'read' faces
Medicine & Health / Psychology & Psychiatry
6 hours ago |
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(PhysOrg.com) -- Oxford University scientists are using brain-scanning technology to understand how we learn to recognise and 'read' faces as children.
The court will now call its expert witness: the brain
Medicine & Health / Neuroscience
10 hours ago |
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(PhysOrg.com) -- Will advances in neuroscience make the justice system more accurate and unbiased? Or could brain-based testing wrongly condemn some and trample the civil liberties of others? The new field ...
Formerly conjoined twins to need years of care
12 hours ago |
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(AP) -- Formerly conjoined Bangladeshi twins separated this week in a marathon surgery will remain in the care of a humanitarian group for at least two years, the organization's CEO said Friday.
Researchers Begin to Decipher Metabolism of Sexual Assault Drug
Nov 19, 2009 |
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(PhysOrg.com) -- It’s a naturally occurring brain chemical with an unwieldy name: 4-hydroxybutyrate (4-HB). Taken by mouth, it can be abused or used as a date-rape drug.
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.
1 conjoined twin talking after separation surgery
Nov 19, 2009 |
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(AP) -- A Bangladeshi toddler separated this week from her conjoined twin sister was talking and behaving normally Thursday after waking from a medically induced coma, the head of the surgery team said.
New Down syndrome treatment suggested by study in mice
Nov 18, 2009 |
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At birth, children with Down syndrome aren't developmentally delayed. But as they age, these kids fall behind. Memory deficits inherent in Down syndrome hinder learning, making it hard for the brain to collect experiences ...
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 (19) |
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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, ...
Formerly conjoined twins in stable condition
Nov 17, 2009 |
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(AP) -- A team of 16 surgeons and nurses successfully concluded 25 hours of delicate surgery Tuesday to separate twin Bangladeshi girls who had been joined at their heads, sharing blood vessels and brain ...
Researchers find explanation for rapid maturation of neurons at birth
Medicine & Health / Neuroscience
Nov 17, 2009 |
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At the moment a newborn switches from amniotic fluid to breathing air, another profound shift occurs: nerve cells in the brain convert from hyperexcitability to a calm frame against which outside signals can be detected.
World's first delivery of intra-arterial Avastin directly into brain tumor
Nov 17, 2009 |
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Neurosurgeons from NewYork-Presbyterian Hospital/Weill Cornell Medical Center performed the world's first intra-arterial cerebral infusion of Avastin (bevacizumab) directly into a patient's malignant brain tumor. This novel ...
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.
New neuroimaging analysis technique identifies impact of Alzheimer's disease gene in healthy brains
Nov 17, 2009 |
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Brain imaging can offer a window into risk for diseases such as Alzheimer's disease (AD). A study conducted at the University of Kansas School of Medicine demonstrated that genetic risk is expressed in the brains of even ...
