Figure 5From: Circadian genomics of the chick pineal gland in vitroInhibition of melatonin production by light and norepinephrine. Melatonin levels released into media were measured during mid-subjective day and mid-subjective night for cultures that had received a 6-hr light pulse, those that had received a 6-hr dose of NE (3 × 10-8 M), and for control cultures which had received no light or a vehicle solution. Significant difference (p < .05) between experimental treatments and controls for each timepoint is indicated by *. Significant difference (p < .05) between CT6 and CT18 timpoints within each treatment group is indicated by †.Back to article page