A CHRONOLOGICAL STUDY OF MITOTIC ACTIVITY IN SATELLITE CELL HYPERPLASIA ASSOCIATED WITH CHROMATOLYTIC NEURONS

After axotomy, spinal ganglia show an increase in the ratio of satellite cells to neurons. The objective of this study is to clarify the temporal aspects of the satellite cell hyperplasia and the role of mitotic activity in this proliferative response. The ventral rami of the fourth, fifth and sixth lumbar spinal nerves in 100 gm female rats were sectioned on the right side. Corresponding left spinal nerves were kept intact and served as controls. After axotomy, representative animals were sacrificed over a twenty day period. Six hours before sacrifice, 0.12 mg of colchicine was given intraperitoneally. Right, experimental and left, control ganglia were removed and an inventory of neurons, satellite cells, and mitotic figures was conducted. An increase in the number of satellite cells was noted on the first day after axotomy; it reached a maximum on the sixth day and disappeared by the eighteenth day. Mitotic activity was observed in all experimental ganglia, but not in the control tissue. © 1969 Springer-Verlag.