Figure 3

Neuregulin-1 blocks DFP-induced microglia activation in the cortex and thalamus. The ED-1 antibody was used to identify macrophages and activated microglia 24 h following DFP and NRG-1 administration. There was virtually no ED1 immunoreactivity detected (red labeling; arrows) in the brain of control animals (A), but there were numerous ED1 immunopositive cells detected in the thalamus (B) and cortex (D) of DFP treated animals. Treatment with NRG-1 significantly decreased the number of ED1 immunopositive cells detected in the thalamus (C) and cortex (E) of DFP intoxicated animals. Dual labeling for ED-1 and FJB (green labeling) showed that activated microglia were seen in areas of the DFP-exposed cortex with significant neurodegeneration (F) and that neither activated microglia nor injured neurons were observed in the cortex of DFP-intoxicated animals that were pretreated with NRG-1 (G). Scale bar = 50 μm.