Nanoparticles can aid in stroke therapy

Tiny selenium particles could have a therapeutic effect on ischemic brain strokes by promoting the recovery of brain damage. Pharmacologists, including Alireza Mashaghi from the Leiden Academic Centre for Drug Research discovered ...

New microscopy technique peers deep into the brain

In order to understand the brain, scientists must be able to see the brain—cell by cell, and moment by moment. However, because brains comprise billions of microscopic moving parts, faithfully recording their activity comes ...

Virtual lens improves X-ray microscopy

With X-ray microscopes, researchers at PSI look inside computer chips, catalysts, small pieces of bone, or brain tissue. The short wavelength of the X-rays makes details visible that are a million times smaller than a grain ...

Researchers report innovative optical tissue imaging method

A UK-wide research team, led by the University of St Andrews, has developed an innovative new way to optically image through tissue, which could allow for a more detailed understanding and diagnosis of the early stages of ...

Ant soldiers don't need big brains

Army ant (Eciton) soldiers are bigger but do not have larger brains than other workers within the same colony that fulfill more complex tasks, according to a study published in the open access journal BMC Zoology. A collaborative ...

A new gelling molecule for growing neurons in 3-D

A multidisciplinary team of researchers from CNRS, INSERM and Université Toulouse III – Paul Sabatier has developed a hydrogel that can grow, develop and differentiate neural stem cells. This biomaterial could provide ...

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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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