Immunohistochemical and morphometrical development of the dorsal root ganglion as a neural crest derivative: comparison with the fetal CNS.
The developmental difference between the dorsal root ganglion (DRG), paravertebral ganglion (PVG) and the central nervous system (CNS) in embryos and fetuses was investigated using immunohistochemical (neuron-specific enolase (NSE) and human natural killer-1 (HNK-1)) and morphometrical methods. NSE positive cells developed from 7 weeks of gestation in the DRG as early as the anterior horn cells of the spinal cord, while the pyramidal cells of the cerebral cortex matured after 20 weeks of gestation. HNK-1 positive granules were present until 14 weeks gestation in the spinal cord and until 26-27 weeks in the DRG and PVG. This early development of DRG cells may be closely related to the peripheral organ maturation during the embryonic or early fetal period.