Fig. 3

Expression of Doublecortin (DCX) in Dorsal Dentate Gyrus Following Intranasal Co-administration of Galanin Receptor 2 and NPY1R Agonists. This figure presents an examination of DCX-labeled cells in the dorsal dentate gyrus after intranasal administration of the Galanin 2 receptor agonist (M1145) and NPY1R receptor agonist, either alone or in combination, and with or without the GAL 2 receptor antagonist (M871). a, d DCX-positive cells were found in the subgranular zone (Sgz) of the dentate gyrus, along the junction between the granular cell layer (Gcl) and the polymorphic layer (P) (Bregma: − 5.6 mm; according to Paxinos and Watson stereotaxic atlas, 2006). b A quantitative analysis of total DCX-immunoreactive (IR) cells in the dentate gyrus of the dorsal hippocampus was conducted following administrations of Control, M1145, NPY1R agonist [Leu31-Pro34]NPY, or co-administration of both agonists with or without M871. Data are presented as mean ± SEM. Intriguingly, the co-administration of M1145 and the NPY1R agonist resulted in a notable increase in the number of DCX-positive cells in the dorsal hippocampus in contrast to the effects of individual peptides and the control group. This effect, however, was offset by the GALR2 antagonist M871. Statistical significance was calculated via one-way ANOVA followed by Newman-Keuls post-hoc test, with *P < 0.05 vs the rest of the groups d The intranasal co-administration of M1145 and NPY1R agonist noticeably increased DCX immunolabeling compared to the control group c. Arrows indicate examples of DCX positive neurons, and dashed lines mark the Gcl of the dentate gyrus. Abbreviations: Control = Distilled water; M1145 = Galanin 2 receptor agonist 132 µg; Y1R = NPY1R receptor agonist [Leu31-Pro34]NPY 132 µg; M1145 + Y1R = Co-administration of M1145 and NPY1R; M1145 + Y1R + M871 = Co-administration of M1145, NPY1R, and GALR2 antagonist M871 132 µg.