Fig. 4

Evaluation of Iba1⁺ cells in the hippocampus of SAM mice aged 2 and 10 months. Thirty micrometers brain coronal cryostat sections obtained as in material and methods were stained with Iba1 (red) and nuclei with DAPI (blue). (a) (i) Hpp area used in the quantification of Iba1⁺ are surrounded by a box, differing in CA1 (cornus ammonis, dark green) and DG (dentate gyrus, soft green), as shown in the scheme. (ii) Scheme of sample collection: six coronal sections, 30 μm each, separated 300 μm one to each other were collected and processed. Sampling started at first appearance of the infrapyramidal blade of the dentate gyrus (DG) from approximately Bregma −1.2 mm to −2.7 mm. (iii) Representative map of the hippocampus (Hpp) showing the expression of BP Iba1⁺ myeloid cells Iba1⁺ in 10 m SAMR1 mice and indicating the regions used for counting. Images at ×40 (×1.7 digital zoom) were obtained with a Leica SP5 TCS inverted fluorescence confocal microscope and the areas were processed and evaluated with ImageJ. stratum oriens (so); stratum pyramidale (sp); stratum radiatum (sr); stratum lacunosum-moleculare (sm); stratum moleculare (sm), granule cell layer (sg); polymorph layer (po). Scale bars are included in the image. (b) (i) Quantification of Iba1⁺ cells in the area described in 2 months (triangles) and 10 months (circles) SAM mice. Data are number on Iba1⁺ cells per individual Hpp (n = 5 male). (ii) Fold change of Hpp Iba1⁺ of 10 months versus 2 months in SAMR1 and SAMP8 mice. *p < 0.05; **p < 0.01, and ***p < 0.001 with respect to Iba-1 +/mm² cells in Hpp from SAMR1 2m (n = 5 males). In (i) and (ii) SAMR1 data are shown in green and SAMP8 in red