Fig. 7

SRF ablation modulates epilepsy associated neuron loss, mossy fiber sprouting and inflammation. a Four weeks after induction of an pilocarpine-mediated SE, hippocampi of heterozygous and SRF deficient animals were analyzed histologically with several markers as described below. b-e Fluoro-Jade B (FJB) labels degenerating neurons. Expectedly, no FJB signals were detectable in non-epileptic heterozygous (b) or mutant (c) hippocampi. Four weeks after an SE, FJB signals were increased in heterozygous (d) but not SRF deficient (e) animals. f-i NeuN labels all neuronal nuclei. In epileptic control animals, neuron loss was observed in the CA3 region (arrows in h). This was diminished in mutant animals with an SE (i). j-m ZnT3 labels hippocampal mossy fibers. No mossy fiber sprouting by granule cells was observed in the molecular layer of the dentate gyrus of non-epileptic heterozygous (j) or mutant (k) animals. In contrast, mossy fiber axon sprouting was observed in heterozygous animals with an SE (arrows in l) but not as pronounced in Srf mutant animals (m). n-q Microglia were labeled by anti-IBA1 directed antibodies. Only in epileptic control animals (p), a strong presence of microglia was observed. Of note, the area occupied by microglia was identical to the region of strongest neuronal demise (compare p with d). r-u Quantification of FJB (r), NeuN (s), ZnT3 (t) and IBA1 (u) signals in the hippocampus. Data are represented as mean ± SD. Individual animals are labeled with grey circles. Scale-bar (b-i; n-q) = 200 μm; (j-m) = 75 μm