Figure 1. Sympathetic stellate ganglion; most cardiac-projecting neurons have their origins in this ganglion. Developmental profile with immunohistochemistry for the noradrenergic marker tyrosine hydroxylase (TH; green) in sheep. Sheep sympathetic neurons express TH by E100 with more prominent expression by E129; staining is localized in neuronal cytoplasm (white arrowheads) and within nerve bundles and fibers (gray arrowheads) at all ages examined (Jonker S., Louey S., Moses M., Macek A., Giraud G., Thornburg K., Hasan W.; unpublished data). Scale bar in C is 200 υm.