News tagged with brain tissue

Related topics: brain , nerve cells , alzheimer s disease , brain tumors , neurodegenerative diseases

Zebrafish help to unravel Alzheimer's disease

New fundamental knowledge about the regulation of stem cells in the nerve tissue of zebrafish embryos results in surprising insights into neurodegenerative disease processes in the human brain. A new study by scientists at ...

Aug 19, 2014
popularity 5 / 5 (3) | comments 0

BPA affects sex-based behavior in mice

(Medical Xpress)—Bisphenol A (BPA) is a common chemical found in household plastics. Previous studies on rodents show that BPA exposure is associated with problems with brain and behavioral development. ...

May 28, 2013
popularity 5 / 5 (8) | comments 5 | with audio podcast report

New study finds brain tumors can arise from neurons

(Medical Xpress)—Researchers from the US and Japan have shown that an aggressive type of brain tumor can arise from normal cells in the central nervous system such as neurons. The cells revert to an earlier, ...

Oct 19, 2012
popularity 5 / 5 (4) | comments 1 | with audio podcast report

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.

This text uses material from Wikipedia licensed under CC BY-SA