(a) Double immunolabeling for ATF3 and CSF1 in sensory neurons at different time points after nerve injury; (b) Percentage of ATF3-expressing neurons that co-express CSF1. CSF1 is detected in a subset of ATF3- expressing neurons within 18 h of nerve injury and persists for at least 3 weeks. At least 150 ATF3-expressing neurons were counted in each mouse. N = 3 mice per time point. Scale bar represents 100 µm. Data are presented as mean ± s.e.m.