Figure 3.

Alterations in calbindin immunoreactivity in GFAP-IL6 transgenic mice. Low-power view of a 3-month-old (no differences were observed between 3- and 12-month-old nontransgenic mice) nontransgenic mouse (a) and a 3-month-old heterozygous GFAP-IL6 transgenic mouse (b) shows strong immunoreactivity in neocortical areas and in hippocampal interneurons (as indicated by the arrow). The molecular layer (ML) and mossy fiber bundle (MF) also displayed intense calbindin immunoreactivity while the pyramidal cell layer (PL) neuropil was mildly labeled. In contrast, a 12-month-old heterozygous GFAP-IL6 transgenic mouse (c) shows decreased calbindin immunoreactivity in the neocortex and hippocampus. Higher-power view of nontransgenic (d) and a 3-month-old heterozygous GFAP-IL6 transgenic mouse (e) shows strong immunoreactivity associated with neocortical interneurons in layers 2–5. The neuropil in layers 1–3 and layer 5 show a moderate level of immunostaining. In contrast, a 12-month-old heterozygous GFAP-IL6 transgenic mouse (f) shows a widespread decrease in calbindin-IR neurons in all layers of the neocortex. [Bars = 1 mm (c) and 0.1 mm (f).]