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.
The ventral tegmental area, (VTA), is a very important brain area in the field of drug abuse. It is one of only two main areas that contain DOPAMINE cell bodies. The MESOLIMBIC DOPAMINE pathway originates in the VTA. Dopamine neurons in the VTA project to areas of the brain associated with emotion and motivation, the so-called limbic areas. However, the projection to the NUCLEUS ACCUMBENS is the most important in understanding the action of drugs of abuse, especially psychostimulants. In addition, neurons in the nucleus accumbens and other limbic areas project to the VTA, providing the substrate for many neurochemicals to modulate the dopa-mine cells in the VTA.
There are two main experimental paradigms used in animals to assess the effects of drugs and endogenous neurotransmitters, such as DYNORPHIN, on these dopaminergic cells at the level of the VTA. Chemicals can be injected directly into the VTA in order to study their effects. Conditioned place preference is a method, which allows the animal to be tested for the REINFORCING properties of a chemical in a drug free state. In addition, increases in locomotor activity can be measured, psychomotor stimulants in addition to being rewarding increase locomotor activity, and one substrate underlying this increase is the VTA.
The most extensively studied drugs of abuse, psychostimulants and opiates, both interact with the mesolimbic dopamine system. Future studies fully elucidating the modulation of VTA dopamine neurons will greatly contribute to the understanding of the mechanism of action of drugs of abuse, and may lead to the development of medications to treat drug abusers.