The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
A synapse is the junction between one neuron and another in the nervous system. It is via the synapses that neurons communicate. The synapse is a microscopic gap--as minuscule as 100nm--between the terminal endings of the first cell (the pre-synaptic neuron), and the dendrites of the adjoining cell (the post-synaptic neuron). This gap, called the synaptic cleft, contains extracellular fluids consisting of ions and degrading enzymes that are "taken up" as necessary by the pre- and post-synaptic neurons in order for them to transmit information effectively. The pre-synaptic terminals store different kinds of neurotransmitters in tiny capsules called synaptic vesicles; the post-synaptic dendrites are equipped with a multitude of receptors, each one designed to receive (or up-take) specific ions, proteins, or neurotransmitters. When an action potential in the pre-synaptic neuron travels down its axon and reaches the pre-synaptic terminals, a complicated electrochemical process causes the synaptic vesicles to burst open, releasing neurotransmitters into the synaptic cleft. Here they quickly accumulate and begin to bind to their appropriate receptor on the post-synaptic dendrites. These chemicals excite the post-synaptic neuron, stimulating an action potential in that cell, which causes it, in turn, to release neurotransmitters into the synaptic cleft between it and its adjacent neuron. Thus, the message is carried from neuron to neuron via the synapses to the target--for example, to muscles of the eye lid telling it to blink.