Figure 1. Effect of acute central injection of Kp10 on food intake and expression of genes encoding hypothalamic peptides NPY, POMC and RFRP-3 in 48 hours fasted female jerboas at spring and autumn.

(A,B) Cumulative food intake (g food intake/100 g body weight) measured 1 h, 2 h, 3 h, 5 h, and 24 h following icv injection of 4 μg Kp10 or vehicle (0.9% NaCl) in 48 h-food deprived female jerboas captured in spring (A) or autumn (B). Statistical evaluation was performed using two-way repeated measures ANOVA followed by Student-Newman-Keuls test; data are expressed as mean ± SEM (n = 4 per group). ***p < 0.001 and *p < 0.05 for significant differences between Kp10 and vehicle injected groups. (C) Semi-quantitative analysis of the labeling intensity of Npy mRNA in the arcuate nucleus (upper left panel), and quantitative measure of the number of neurons expressing Pomc mRNA in the arcuate nucleus (upper middle panel) and Rfrp mRNA in the dorso/ventro medial hypothalamus (upper right panel) 1h30 after 4 μg Kp10 (black bars) or vehicle (grey bars) icv injections in spring and autumn female jerboas. Statistical evaluation was performed using two-way ANOVA followed by a post hoc Holm-Sidak test; data are presented as mean ± SEM (n = 4 in the spring group; n = 3 in the autumn group). ***p < 0.001 and **p < 0.01 for significant differences between Kp10 and vehicle injected groups and ***p < 0.001 and *p < 0.01 for differences between spring and autumn groups. (D) Representative images of Npy mRNA labeling in the arcuate nucleus (lower left panel), Pomc mRNA labeling in the arcuate nucleus (lower middle panel) and Rfrp mRNA labeling in the DMH/VMH (lower right panel) of jerboas sacrificed in spring 1h30 after Kp10 or vehicle icv injections, Scale bars represent 100 μm. AU: arbitrary units, 3v; third ventricle; Veh: vehicle.