The extracellular matrix glycoprotein tenascin-C supports the enriched environment-stimulated neurogenesis in the adult dentate gyrus of mice.

The extracellular matrix glycoprotein tenascin C (TnC) is implicated in a variety of processes ranging from cell proliferation and adhesion to synaptic plasticity. The contribution of TnC to neurogenesis related processes in the adult hippocampus, however, remains unclear. To address this question, hippocampal sections were immunostained for the proliferation marker Ki67 and for neuroblast marker doublecortin (DCX). Laser scanning confocal microscopy revealed that TnC - deficiency does not alter either the size of Ki67+ or DCX + cellular populations in the subgranular zone (SGZ) compared to the control animals. Super-resolution Airyscan confocal microscopy enabled the investigation of the complexity of dendritic trees of DCX + cells with the analysis of the dendritic tree complexity parameters. The results show that the dendritic tree complexity of developing neurons is not dependent on the presence of TnC. However, reinforcement of adult neurogenesis by the exposure to enriched environment (EE) revealed that TnC- deficient mice have a reduced number of DCX + cells compared to wild type littermates. This study indicates that TnC might not contribute to the basal levels of adult neurogenesis in the hippocampus, while on the other hand it gains importance in the generation of the positive effect of EE.