Figure 3a-c: Feeding activity of P-X pigeons first entrained to LD cycles and then placed into DD and subjected to cyclic vehicle infusions (top boxes). Melatonin infusions were later initiated with a period and phase different than the preceding vehicle infusion (middle boxes). Vehicle infusions were re initiated with the same phase as the previous melatonin infusion (bottom boxes). Periods of infusion (a-c) first vehicle infusion = 24.77; melatonin and second vehicle infusion = 24.50. Melatonin dose a,b) 3.6 uglhr; c) 0.46 uglhr. |