Dietary tryptophan and circadian rhythms

Mice were fed a normal chow diet or a tryptophan depleted diet for two weeks under normal 12-hr light/dark cycles (LD) or in constant darkness (DD). Mice were sacrificed every 4th hour over the 24-hr circadian cycle. The suprachiasmatic nucleus (SCN) was harvested and RNA was isolated using a standard TRIZOL protocol. The data suggest that dietary tryptophan is an important component of the diet regulating circadian homeostsis. Four groups in total: mice fed normal chow or tryptophan depleted diet, exposed to LD cycles or DD. Mice were collected every 4th hour over the circadian cycle, i.e. 6 time-points. Three mice were used from each group and time point. The RNA was sequenced in the SCNs of the mice.