Correlative histochemical and morphological study on the maturation of sensory ganglion cells in the rat

Summary In neonatal rats the sensory ganglion cells are uniform in size and in their stainability with hematoxylin and eosin. At this stage the cells differ, however, in the intensity of staining for RNA and for various enzyme activities. With maturation the ganglion cells differentiate into light (mostly large) cells, and dark (mostly small) cells. The differentiation is accompanied by changes in intensity of various enzyme activities. In sections stained for acid phosphatases and acetylcholine esterase, maturation was associated with a higher activity in the small than in the large cells, whereas with thiamine pyrophosphatase it was associated with a higher activity in the large than in the small neurones. With non-specific cholinesterase, maturation of all cells was accompanied by loss of activity in perikarya and increased activity in axons and satellite cells. With monoamine oxidase, the changes during maturation differed in the trigeminal from the spinal ganglion cells.The findings indicate that the difference between small and large cells might have a functional significance, the nature of which is discussed.