News tagged with axons

Related topics: nerve cells · neurons · brain · neurodegenerative diseases · cells

Model for brain signaling flawed, new study finds

A new study out today in the journal Science turns two decades of understanding about how brain cells communicate on its head. The study demonstrates that the tripartite synapse – a model long accepted by the scientific ...

Jan 10, 2013
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Study helps explain how we can sense temperatures

Scientists at The Scripps Research Institute and the Genomics Institute of the Novartis Research Foundation (GNF) have shed new light on the molecular mechanism that enables us to sense temperature, such as the heat from ...

Apr 23, 2010
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How injured nerves grow themselves back

Unlike nerves of the spinal cord, the peripheral nerves that connect our limbs and organs to the central nervous system have an astonishing ability to regenerate themselves after injury. Now, a new report in the October 1st ...

Sep 27, 2010
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Newly Discovered Gene Mutation Linked to Nerve Diseases

(PhysOrg.com) -- Researchers from the Northwestern University Feinberg School of Medicine have identified mutations in the gene for TRPV4 that cause two related degenerative motor nerve disorders, scapuloperoneal spinal muscular ...

Dec 28, 2009
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Axon

An axon or nerve fiber is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma.

An axon is one of two types of protoplasmic protrusions that extrude from the cell body of a neuron, the other type being dendrites. Axons are distinguished from dendrites by several features, including shape (dendrites often taper while axons usually maintain a constant radius), length (dendrites are restricted to a small region around the cell body while axons can be much longer), and function (dendrites usually receive signals while axons usually transmit them). All of these rules have exceptions, however.

Some types of neurons have no axon—these are called amacrine cells, and transmit signals from their dendrites. No neuron ever has more than one axon; however in invertebrates such as insects the axon sometimes consists of several regions that function more or less independently of each other. Most axons branch, in some cases very profusely.

Axons make contact with other cells—usually other neurons but sometimes muscle or gland cells—at junctions called synapses. At a synapse, the membrane of the axon closely adjoins the membrane of the target cell, and special molecular structures serve to transmit electrical or electrochemical signals across the gap. Some synaptic junctions appear partway along an axon as it extends—these are called en passant ("in passing") synapses. Other synapses appear as terminals at the ends of axonal branches. A single axon, with all its branches taken together, can innervate multiple parts of the brain and generate thousands of synaptic terminals.

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

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