Morphology and identification of SGN. (A) The morphology of SGN. This picture shows the SGN, which are comprised of elliptical nuclei and bipolar axons (shown at 100× magnification). (B) The test for β-III-tubulin (TUJ1) by immunofluorescence in the SGN. TUJ1 is mainly expressed in cytomembrane and axons. The nuclei were stained with DAPI (1:10,000), as indicated by blue fluorescence (400× magnification).