NUCLEAR POPULATION CHANGES IN DEGENERATING POSTERIOR COLUMNS OF RABBIT’S SPINAL CORD

Abstract

Changes in the nuclear population in the posterior columns of the spinal cord of the rabbit were studied after 10, 20, 50, and 100 days'' degeneration. There is an increase in the number of nuclei that may amount to 4.5 times the normal after 100 days'' degeneration. Except for the 20-day cords, there is no significant change in the area of the posterior columns. There is no significant change in the length of the nuclei after all periods of degeneration studied. Comparison is made between the nuclear population changes in degenerating peripheral nerves and in the posterior columns of the spinal cord. Most of these differences are probably due to the difference in structure of the nerve fiber sheaths; the main difference is the presence of a fairly rigid tube in the peripheral nerve due to the neurilemma and endoneurium.