Neuroscience

Older brain cells linger unexpectedly before their death

For oligodendrocytes—the central nervous system cells critical for brain function—age may not bring wisdom, but it does come with the power to cling to life for much, much longer than scientists knew. That's according ...

Alzheimer's disease & dementia

Unlocking how to use mRNA to target Alzheimer's disease

Scientists at The Florey have developed an mRNA technology approach to target the toxic protein tau, which builds up in patients with Alzheimer's disease and other dementias.

Parkinson's & Movement disorders

New tool detects signs of motor neuron disease before symptoms begin

Scientists from the University of Aberdeen in collaboration with the University of Edinburgh and international partners, have identified a new way to detect signs of motor neuron disease (MND) in brain tissue that can pick ...

Neuroscience

Brain circuit that spoils appetite identified

Satiety, nausea or anxiety can all lead to a loss of appetite. Delaying eating can be a healthy move by the body to prevent further damage and to gain time for regenerating. Researchers at the Max Planck Institute for Biological ...

Neuroscience

Researchers introduce enhanced brain signal analysis technique

University of Minnesota Medical School researchers have introduced a new, refined method for analyzing brain signals, enhancing our understanding of brain functionality. This research has the potential to improve treatments ...

page 1 from 40

Brain

The 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.

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