After a little more than 20 years since the original discovery of neuropeptide Y (NPY) by Tatemoto and colleagues, the field of NPY research has made remarkable progress and is coming of age.The present volume addresses all major topics in connection with NPY and related peptides by established leaders in their respective areas. Experienced NPY-aficionados will certainly find new and useful additional information in this volume and newcomers to the field will hopefully discover how much exciting research this still has to offer.