News tagged with human brain

Related topics: brain , genes , brain cells , neurons , neuroscientists

How the brain makes decisions

Some types of decision-making have proven to be very difficult to simulate, limiting progress in the development of computer models of the brain. EPFL scientists have developed a new model of complex decision-making, ...

18 hours ago
popularity 77 comments 0

Brain scan reveals out-of-body illusion

The feeling of being inside one's own body is not as self-evident as one might think. In a new study from Sweden's Karolinska Institutet, neuroscientists created an out-of-body illusion in participants placed ...

Apr 30, 2015
popularity 576 comments 1

Study deciphers the noise in the human brain

By directly recording electrical activity from the human brain, neuroscientists at the Stanford University School of Medicine have shown that distinct, distant groups of brain areas that support memory retrieval ...

Apr 09, 2015
popularity 21 comments 1

What autism can teach us about brain cancer

Applying lessons learned from autism to brain cancer, researchers at The Johns Hopkins University have discovered why elevated levels of the protein NHE9 add to the lethality of the most common and aggressive ...

Feb 09, 2015
popularity 196 comments 10

Human brain

The human brain is the center of the human nervous system and is a highly complex organ. Enclosed in the cranium, it has the same general structure as the brains of other mammals, but is over three times as large as the brain of a mammal with an equivalent body size. Most of the expansion comes from the cerebral cortex, a convoluted layer of neural tissue that covers the surface of the forebrain. Especially expanded are the frontal lobes, which are involved in executive functions such as self-control, planning, reasoning, and abstract thought. The portion of the brain devoted to vision is also greatly enlarged in humans.

Brain evolution, from the earliest shrewlike mammals through primates to hominids, is marked by a steady increase in encephalization, or the ratio of brain to body size. The human brain has been estimated to contain 50–100 billion (1011) neurons[citation needed], of which about 10 billion (1010) are cortical pyramidal cells.[citation needed] These cells pass signals to each other via approximately 100 trillion (1014)[citation needed] synaptic connections.

In spite of the fact that it is protected by the thick bones of the skull, suspended in cerebrospinal fluid, and isolated from the bloodstream by the blood-brain barrier, the delicate nature of the human brain makes it susceptible to many types of damage and disease. The most common forms of physical damage are closed head injuries such as a blow to the head, a stroke, or poisoning by a wide variety of chemicals that can act as neurotoxins. Infection of the brain is rare because of the barriers that protect it, but is very serious when it occurs. More common are genetically based diseases[citation needed], such as Parkinson's disease, multiple sclerosis, and many others. A number of psychiatric conditions, such as schizophrenia and depression, are widely thought to be caused at least partially by brain dysfunctions, although the nature of such brain anomalies is not well understood.

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