<p>Signal transduction is the movement of information across different levels of order, with concomitant translation of the informational content into the appropriate format. The term “signal transduction” originated in the physical sciences, but over the past 25 years, it has become a key concept in cell and molecular biology. The mechanisms of action of both psychopharmacology and psychotherapy involve signal transduction at several levels. </p> <h4>ABOUT THE AUTHOR</h4> <p>George I. Viamontes, MD, PhD, is Regional Medical Director, United Behavioral Health Inc., St. Louis, Missouri, and Assistant Clinical Professor, Department of Psychiatry, University of Missouri-Columbia, Columbia.</p><p>Address correspondence to: George Viamontes, MD, PhD, Regional Medical Director, UBH, 13655 Riverport Drive, Fourth Floor, St. Louis, MO 63043; or e-mail <a href="mailto:viamonte@sbcglobal.net" target="_new">viamonte@sbcglobal.net</a>.</p><p>Dr. Viamontes has disclosed no relevant financial relationships.</p> <h4>EDUCATIONAL OBJECTIVES</h4> <ol> <li> Determine how sensory information is converted to neural impulses.</li> <li>Assess the mechanism of action of the four major types of neural signal transduction at the cellular level. </li><li>Describe the mechanism of action of the major neurotransmitter receptors in the brain.</li> </ol>