FIGURE 1.

Schematic representation of the photoperiod protocols used throughout gestation. Three cohorts of female rats raised and maintained in photoperiod 12-h light and 12-h dark were mated and separated into three groups: LD photoperiod, CPS photoperiod, and CPS+Mel, corresponding to females under CPS that received melatonin in drinking water during subjective night (19:00–07:00). In CPS, the photoperiod was shifted by 12 h for three consecutive cycles, after which the dark phase was extended for 12 h to restore the original photoperiod for a further 4 days. The melatonin treatment was available from GA 1 until delivery (GA, gestational age).