Figure 5.

Tau-Immunoreactive Granules Are Associated with Reactive Astrocytes

(A) Immunofluorescent confocal images of aged (21-mo) 3xTg-AD mice show distal processes of microglia detected with anti-rabbit Iba1 (Iba1, green) that associate with and envelop anti-mouse IgG1-specific tau5_IR granules (Tau5 IgG1, red) in the CA1 and SR of aged 3xTg-AD mice.

(B) Distal processes of astrocytes detected with anti-rabbit GFAP (GFAP, green) contain and envelop many anti-mouse IgG1-specific tau5_IR granules (Tau5 IgG1, red) in the CA1 and SR of aged 3xTg-AD mice.

(C) Confocal images of dual in situ RNA labeling and immunofluorescence shows Serpina3n expression (red) in processes of reactive astrocytes (GFAP, green) entangled with T22-positive hippocampal clusters (T22, cyan). Robust expression of Ppib (positive control, red) is also detected in affected astrocytes (green) and other cells (DAPI, blue), whereas the negative control probe (red) is not detected in the hippocampus. Scale bars, 10 μm; arrowheads indicate sites of co-localization. See also Figure S5.