Gender differences in doublecortin expression in the dentate gyrus of the Wistar rat during development

Objectives: Neurogenesis is the formation process of functional neurons from progenitor cells which continues during lifetime. Alterations in neurogenesis is associated with neurodegenerative disorders (ND). Different mechanisms underlie the ND in males and females which may be related to neurogenesis. In this study, we aimed to investigate the developmental process of neurogenesis in the hippocampus of male and female rats at different ages and shed light on the effect of gender difference on ND. Methods: Brains were obtained from 7, 14, 21 days and 3-month-old male and female Wistar rats following intracardiac perfusion and processed for immunohistochemical and immunoflorescence staining. Doublecortin protein (DCX) was used as a marker of newly-born neuroblasts to determine neurogenesis. Results: DCX immunoreactive (-ir) cells were dispersed throughout the granular and subgranular layers of DG in 7-days-old group in both genders. However, in the 14 and 21 days old groups, DCX-ir cells were observed only in the subgranular zone in the sections labelled with both immunohistochemistry (IHC) and immunoflourescent (IF) methods. In all age groups, female rats had a tendency to increase in DCX immunoreactivity when compared to that of male Wistar rats. Conclusion: DCX-ir cells may be localized in different parts of DG during development. The number of newly born neurons showed a tendency to increase in female rats in all groups. Further studies are needed to understand the reason for differences in the normal developmental neurogenesis process between two genders.