Figure 5. The expression of ErbB4 was positively correlated with PV interneurons in the spinal cord of ALS mice by immunofluorescence. The yellow boxes represent the typical positive cells (enlarged approximate twice on the original position). The typical PV, MMP-9 and ErBb4 positive cells are enlarged approximately 4 times and shown on the top right panel. Scale bar = 100 μM (A). The expression of ErbB4 was tested by RT-qPCR (B) and western blotting (C). Pearson’s correlation for protein levels of PV and ErbB4 in all animals (control and ALS) (D). ***P < 0.001 vs. control at 90~100 days. ###P < 0.001 vs. control at 130~140 days. In all experiments, half male and half female mice were used in each group (n = 6).