Fig. 3.

Effects of photoperiod and melatonin administration on the expression of hamster GnIH precursor mRNA in the diencephalon. Various doses of melatonin (vehicle, 0 g/plate; low, 10 μg/plate; medium, 100 μg/plate; high, 1 mg/plate) were administered sc by means of a SILASTIC plate to Px hamsters maintained in SD for 13 wk. Other hamsters were sham operated and maintained in LD or SD for 13 wk. Each column and the vertical line represent the mean ± sem (n = 4 samples; one sample from one animal). Different letters (a, b) indicate statistical differences (P < 0.05) by one-way ANOVA, followed by Bonferroni's multiple range test.