In the forty years since melatonin's isolation and characterization, a large and multifaceted database has accrued. This book documents the diverse research contributions of most of the major laboratories in the field of melatonin research, as presented in a special conference to mark the 40 year anniversary of the isolation and chemical identification of this hormone. In addition, many chapters by younger scientists provide an exciting glimpse of where melatonin research is heading in the future.