Development and differentiation of fetal rat sensory ganglia and spinal cord segments in vitro

Summary Fetal spinal ganglia and spinal cord segments with adhering spinal ganglia were explanted on collagen-coated coverslips. They were investigated with enzyme histochemical methods for the existence of hydrolases and dehydrogenases up to 54 days of cultivation.Alkaline phosphatase was located in arachnoid cells and in mantle cells (satellite cells). Butyrylcholinesterase and alpha-glycerophosphate-menadione-tetrazolium reductase were found in mantle cells. Acetylcholinesterase and indoxylesterase were active in the whole neuron; acid phosphatase and alpha-naphthylacetate esterase were restricted to the perikarya.During the process of cell differentiation in vitro alkaline phosphatase decreased in mantle cells. Acid phosphatase became diminished distinctly in spinal ganglion cells. The other neuronal enzymatic activities remained unaltered during the whole period of cultivation. Proliferated Schwann cells were conspicuous by their activity for butyrylcholinesterase. In newly formed myelin sheaths arylsulphatase was active. Lactate dehydrogenase was contained in the perineurium which had developed. Cultures of long duration could contain cytological formations which were reminiscent of sensory end-organs with respect to their enzyme patterns.The enzyme activities of nervous tissues in vitro in their approximation to the situation in situ are discussed.A preliminary report was presented at the 17th Meeting of the Association of German Neuropathologists and Neuroanatomists, in Freiburg, September 1972.The skilled technical assistance of Miss Johanna Sixel and Miss Charlotte Beyer is gratefully acknowledged.