Figure 3

Short photoperiod reduced midbrain monoamine content at multiple stages of development. (A) 5-HT content, (B) 5-HIAA levels, (C) DA content, and (D) DOPAC levels in the midbrain. Mice developed under either Equinox (Eq), Long (L), or Short (S) photoperiods and monoamine levels were measured at three time points: P8, P18, and P35. The significant levels were as follows: (**p < 0.01, ***p < 0.001). The significance levels in (A) are shown for Long (L) to Equinox (Eq) at P18, and for Long (S) to Short (S) comparisons at P35. In addition, a significant Holm–Sidak’s post hoc test revealed differences between Equinox and Short (p = 0.0014) groups for (A) 5-HT content at P35. The significance levels in (B) are shown for Long (L) to Short (S) comparisons at P18. The significance levels in (C) and (D) are shown for Long (L) to Short (S) comparisons at P35. Lastly, a significant Holm-Sidak’s post hoc test revealed differences between Equinox and Short (p = 0.0493) groups for (C) DA content at P35.