The new potential of an "old" enzyme Glycogen Synthase Kinase 3 (GSK-3) was discovered about twenty-five years ago but had garnered little interest until recently. Now many researchers believe that there is much potential for this "old" enzyme and are re-examining its biological characteristics. GSK-3 and its inhibitors could lead to effective treatments for neurogenerative disorders, type II diabetes, depression and bipolar disorder, and some forms of cancer. This book explores the nature of this promising enzyme, providing a thorough introduction and discussion, and mentions the birth of several chemical families of GSK-3 inhibitors with varying selectivity. Specific topics relating to GSK-3 covered in this book include: * Cellular functions * Neuronal cell biology * Crystal structures * Kinase-kinase and site-site interactions in the phosphorylation of tau * Therapeutic target in human pathology * Role in stem cells * Physiology studies * Development and therapeutic potential of GSK-3 inhibitors Gathering and systematically analyzing relevant and up-to-date information about GSK-3 and its known inhibitors, this book will aid researchers interested in drug design and development, especially those directly involved in the fascinating world of GSK-3.