Figure 3: Photomicrographs of sections from hippocampus (CA1 field) of rats from Groups I (intact control), II (STZ-diabetic), III (C60HyFn control), IV (STZ-diabetic animals pre-treated with C60HyFn – prophylactic regime), and V (STZ-diabetic animals treated with C60HyFn – therapeutic regime) stained immunohistochemically for glial fibrillary acidic protein (GFAP). Astrocytes (yellow arrows) are seen as brown-coloured stellar-like cells with numerous processes. Scar-forming astrocytes (black arrows) are visualized as hypertrophic cells with increased number of processes. GFAP immunostaining demonstrates that STZ-diabetes induces global increase in astrocyte size, number and density, which altogether are the hallmark of severely reactive astrogliosis. C60HyFn reduces the number of GFAP-positive astrocytes in diabetic rat brain administered in both regimes. All sections were additionally counterstained with hematoxylin to visualize cell nuclei; layer of neural cell bodies is indicated at the top left. Original magnification ×200.