FIG. 1.

S100β-immunoreactivity (S100β⁺) in tissue sections of rat cerebrum showing increases in number, size, and immunoreactive intensity of S100β⁺ astrocytes (brown) in IL-1β–injected animals. As illustrated here, some S100β⁺ astrocytes could also be found in PBS-injected animals, but the number of these cells was not significantly different from controls (see Fig. 2). (A) Uninjected control rat; (B) PBS-injected rat; (C) IL-1β–injected rat. Bars = 15 μm.