The dopaminergic neuron depicted on the front cover of the book has been treated invitrowith GDNF (glial cell line-derived neurotropic factor). Compared to control (nontreated) cells (back cover), the cell has become more dendritic. The deeper red color also indicates that it makes more of a key enzyme for dopamine biosynthesis. GDNF may hold promise in the treatment of Parkinson's disease. (Photographs courtesy of Lin et al., Synergen, Inc.)The fifth edition of the most widely used college text of endocrinology has been extensively revised to provide the most up-to-date information available in the field of endocrine physiology. The book presents in-depth discussions of the vertebrate hormones provided in the following logical and meaningful manner. introduction (historical perspective) biosynthesis chemistry circulation and metabolism physiological roles control of secretion mechanisms of action pathophysiology comparative endocrinology Many new figures have been provided that help convey concepts to the reader in a most information manner.Hadley, Mac E. is the author of 'Endocrinology', published 1999 under ISBN 9780130803566 and ISBN 0130803561.