What is "neuron"

Neuron \Neu"ron\, n.; pl. Neura. [NL., from Gr. ney^ron nerve.] (Anat.)

1. The brain and spinal cord; the cerebro-spinal axis; myelencephalon. [obsolete]
   --B. G. Wilder.

2. (Cell Biology) The characteristic specialized cell that is part of the nervous system, serving to conduct electrical impulses to and from the brain, and also between other parts of the body, and composed of a main cell body, the axon, with a varying number of processes of varying length, the dendrites; a nerve cell. The movement and behavior of higher animals depends on the signals tranmsitted by such nerve cells.

"a nerve cell with appendages," 1891, from German Neuron, from Greek neuron (see neuro-). Used earlier (1884) for "the spinal cord and brain."

n. (context cytology English) A cell of the nervous system, which conducts nerve impulses; consisting of an axon and several dendrites. Neurons are connected by synapses.

n. a cell that is specialized to conduct nerve impulses [syn: nerve cell]

Neuron is a biweekly peer-reviewed scientific journal published by Cell Press, and imprint of Elsevier. It was established in 1988, and covers neuroscience and related biological processes. The Editor in Chief is Katja Brose. Transcript and video available. Click on "Transcript" for text.

• See also: A Career in Science Editing: Katja Brose Editor in Chief, Neuron

A neuron ( or , also known as a neurone or nerve cell) is an electrically excitable cell that processes and transmits information through electrical and chemical signals. These signals between neurons occur via synapses, specialized connections with other cells. Neurons can connect to each other to form neural networks. Neurons are the core components of the brain and spinal cord of the central nervous system (CNS), and of the ganglia of the peripheral nervous system (PNS). Specialized types of neurons include: sensory neurons which respond to touch, sound, light and all other stimuli affecting the cells of the sensory organs that then send signals to the spinal cord and brain, motor neurons that receive signals from the brain and spinal cord to cause muscle contractions and affect glandular outputs, and interneurons which connect neurons to other neurons within the same region of the brain, or spinal cord in neural networks.

A typical neuron consists of a cell body ( soma), dendrites, and an axon. The term neurite is used to describe either a dendrite or an axon, particularly in its undifferentiated stage. Dendrites are thin structures that arise from the cell body, often extending for hundreds of micrometres and branching multiple times, giving rise to a complex "dendritic tree". An axon (also called a nerve fiber when myelinated) is a special cellular extension (process) that arises from the cell body at a site called the axon hillock and travels for a distance, as far as 1 meter in humans or even more in other species. Nerve fibers are often bundled into fascicles, and in the peripheral nervous system, bundles of fascicles make up nerves (like strands of wire make up cables). The cell body of a neuron frequently gives rise to multiple dendrites, but never to more than one axon, although the axon may branch hundreds of times before it terminates. At the majority of synapses, signals are sent from the axon of one neuron to a dendrite of another. There are, however, many exceptions to these rules: neurons that lack dendrites, neurons that have no axon, synapses that connect an axon to another axon or a dendrite to another dendrite, etc.

All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps, which combine with ion channels embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium, potassium, chloride, and calcium. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. If the voltage changes by a large enough amount, an all-or-none electrochemical pulse called an action potential is generated, which travels rapidly along the cell's axon, and activates synaptic connections with other cells when it arrives.

In most cases, neurons are generated by special types of stem cells. It is generally believed that neurons do not undergo cell division but recent research in dogs shows that in some instances in the retina they do. Astrocytes are star-shaped glial cells that have also been observed to turn into neurons by virtue of the stem cell characteristic pluripotency. In humans, neurogenesis largely ceases during adulthood; but in two brain areas, the hippocampus and olfactory bulb, there is strong evidence for generation of substantial numbers of new neurons.

Neuron is one of the primary cell types in the nervous system.

Neuron may also refer to:

• Artificial neuron is the basic unit in an artificial neural network
• Neuron (synthesizer) is an electronic musical instrument
• The Dassault nEUROn is a planned stealth Unmanned combat air vehicle designed by a consortium of European countries
• Neuron (journal) is a scientific journal publishing scholarly neuroscience articles
• Neuron (software) is a simulation environment used in computational neuroscience for modeling individual neurons and networks of neurons
• Neuron Robotics, a robotics development system manufacturer and retailer in Worcester, Massachusetts, United States

Neuron is a simulation environment for modeling individual neurons and networks of neurons. As of version 7.3, Neuron is capable of handling diffusion-reaction models, and integrating diffusion functions into models of synapses and cellular networks. It was primarily developed by Michael Hines, John W. Moore, and Ted Carnevale at Yale and Duke.

NEURON models individual neurons via the use of sections which are subdivided into individual compartments by the program, instead of requiring the user to manually create the compartments. The primary scripting language that is used to interact with it is hoc but a Python interface is also available. The programs for it can be written interactively in a shell, or loaded from a file. NEURON supports parallelization via the MPI protocol. Also, starting with NEURON 7.0 parallelization is possible via internal multithreaded routines, for use on computers with multiple cores. The properties of the membrane channels of the neuron are simulated using compiled mechanisms written using the NMODL language or by compiled routines operating on internal data structures that are set up with a GUI tool (Channel Builder).

NEURON along with the analogous software platform GENESIS are used as the basis for instruction in computational neuroscience in many courses and laboratories around the world.