Fig. 5

Morphological phenotypes of astrocytes in the molecular layer of the dentate gyrus (MolDG) of aged mice raised in enriched environment (A EE mice). Cluster discriminant analysis (Ward’s method) and three-dimensional reconstructions of MolDG astrocytes from five A EE mice. a Dendrogram groupings of 73 dentate gyrus astrocytes indicated two main morphological phenotypes (type I and type II). b Three-dimensional reconstruction of an astrocyte with mean values closer to the mean values of morphometrical features of type I astrocyte. c Graphic representation of the discriminant analysis. The variable that contributed most to cluster formation was complexity (p < 0.46 × 10⁻²⁶). Type I (blue dots) showed higher X–Y dispersion than Type II (orange dots) astrocytes. Astrocytes were reconstructed from both rostral and caudal regions of the dentate gyrus; cluster analysis was based on multimodal or at least bi-modal morphometric features of astrocytes (MMI >0.55). d Three-dimensional reconstruction of an astrocyte with mean values closer to the mean values of morphometrical features of type II astrocyte. Below the three-dimensional reconstructions are the corresponding linear dendrograms of each arbor of astrocytes type I and II. The length of each branch segment is displayed to scale as vertical lines; sister branches are horizontally displaced. The dendrogram was plotted and analyzed using Neuroexplorer (MicroBrightField). Branches of the same parental (primary branch) trunk are shown in one color. A EE aged mice from enriched environment. Scale bars 10 μm