Medications

Inhibiting epileptic activity in the brain

Epileptic seizures often originate in small, localized areas of the brain where neurons abnormally fire in unison. These electrical impulses disrupt proper brain functioning and cause seizures. But what makes regions where ...

Medical research

Targeted ultrasound for noninvasive diagnosis of brain cancer

Brain tumors are typically diagnosed using MRI imaging, as taking a sample for a tissue biopsy is risky and may not be possible due to tumor location or a patient's poor health conditions. Researchers at Washington University ...

Diseases, Conditions, Syndromes

Fat-based molecules are key to Zika virus infection

Certain fat-based molecules required for Zika virus infection in human cells could provide clues to why the virus primarily infects brain tissue, particularly in a developing fetus or newborn.

Neuroscience

Trying to listen to the signal from neurons

Associate Professor Takeshi Kawano, Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology (TUT) and the research team at the Electronics-Inspired Interdisciplinary Research Institute ...

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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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