G-CSF receptor expression after sciatic nerve axotomy. (A) G-CSF receptor is upregulated after sciatic nerve axotomy in spinal cord of neonatal mice. Quantitative PCR for G-CSF receptor of spinal cords of axotomized or not neonatal mice (induction of 55%; n = 3, **p < 0.005). (B) G-CSF receptor staining intensity is stronger on the motoneurons after axotomy. Fluorescent intensity of G-CSF receptor staining on motoneurons was calculated on the ipsi- and contralateral side with an image processing program (*p < 0.05, n = 49).