CNS Drug Reviews, Volume 5, No. 1, Spring 1999

In commemoration of Aaron Lerner’s isolation and chemical identification of the indoleamine hormone N-acetyl-5-methoxytryptamine (better known as melatonin) the Institute for Hormone and Fertility Research at the University of Hamburg called together melatonin researchers, both established and newcomers, to discuss this interesting molecule and its impact on basic and clinical research. In addition to twenty invited speakers, over ninety other scientists from twenty countries, representing five continents were in attendence. Among the submitted abstracts, twenty were selected by the international advisory committee (consisting of J. Arendt, M. Hastings, H. Illnerova, H. W. Korf, A. Lewy, J. Olcese, and S. Reppert) for presentation as selected lectures, while the remaining thirty six were shown as posters. In the first plenary lecture D. C. Klein (National Institute of Health [NIH], Bethesda, MD, USA) presented a detailed historical account of his laboratory’s search for the mechanisms and identity of the enzyme arylalkylamine N-acetyltransferase, the rate-limiting enzyme in the synthesis of melatonin. He described in detail the variety of transcriptional and/or translational regulatory events involved in shaping the predominantly nocturnal activity of this enzyme. P. Voisin (Poitiers, France) discussed the biochemistry of hydroxyindole-O-methyltransferase, the final enzyme in the melatonin synthesizing pathway, whose transcriptional regulation is only beginning to be understood. H. W. Korf (Frankfurt, Germany) delivered a thorough and visually stunning morphological overview of the phylogenetic overhaul to which the pineal organ was subjected in evolving from a “third eye” in lower vertebrates to a strictly neuroendocrine gland in mammals. M. Iuvone (Atlanta, USA) reviewed the data on retinal melatonin biosynthesis, in particular with regard to transcriptional and post-transcriptional regulation of tryptophan hydroxylase (for the synthesis of serotonin — the precursor to melatonin) and arylalkylamine N-acetyltransferase (AA-NA7). Using the chick retina as his model system, he presented a clear scheme for understanding this remarkable circadian oscillator (and its re-