Central neural control of pineal melatonin synthesis in rat

Summary To investigate a possible central neural influence on nocturnal pineal metabolic activity, frontal transsections of the stria medullaris thalami were conducted. Enzymes involved in melatonin synthesis, i.e. N-acetyltransferase and hydroxyindole-O-methyl-transferase, exhibited reduced activities in operated animals when compared to controls. These results indicate a modulatory role of central structures on noctural pineal indole metabolism.This study was supported by the Deutsche Forschungsgemeischaft and the Stifung Volkswagenwerk. The technical assistance provided by M. Henschel, I. v. Graevenitz and G. Schlich is gratefuly acknowledged.