Microglia in the spinal cord of SOD
rats. A-C, double staining for microglia (Iba1) and neurons (NeuN) shows progressive loss of neurons during symptomatic and end stages of motor neuron disease. Microglial activation during symptomatic disease (B) progresses to microglial dystrophy at 6 months of age when animals are terminal (C). Panel D shows close-up of fragmented microglia as seen with OX-42 staining (brown color) during end stage disease. A few surviving motoneurons are stained blue with cresyl violet. Scale bars: 100 μm (A-C); 20 μm (D).