Fig. 5

Effect of neonatal maternal deprivation and leptin treatment on pubertal onset. Age of pubertal onset assessed by vaginal opening (VO) in females (a) and balano-prepurcial separation (BPS) in males (b) in maternal deprivation (MD) or control (Co) rats treated with leptin (Lept) or vehicle (Vh) from postnatal day (PND) 9 until PND13 (n = 10–12). The animals were monitored between days 30 and 38 (females) or days 35 and 47 (males) for VO or BPS, respectively. In females, neonatal leptin treatment delayed the mean age of VO in both control and MD rats, with no effect of MD alone. In males, external pubertal signs were advanced with both MD and leptin treatment, with the combination of these factors normalizing pubertal onset. For the presentation of data, cumulative percentage data of VO/BPS are shown beside the mean age of VO/BPS. Two-way ANCOVA: (b) main effect of leptin treatment. Tukey’s post hoc: ***p < 0.005; *p < 0.05