An experimental study of early ultrastructural changes in the injured spinal cord

Experimental hemisection injury of rat spinal cord was undertaken in order to examine Wallerian degeneration of ascending and descending tracts, and alterations in neurons and synapses. By light microscopy degeneration of axons was recognized first at 72 hours post-operatively. On the other hand, EM study revealed axonal degeneration 24 hours post-operatively. There were several ultrastructural changes in the early stages after hemisection injury. Increase in number of lysosomes in neurones was believed to be related to "autolysis" of the injured spinal cord. Another noteworthy finding was the "separation" of boutons. The mechanisms considered to account for these findings were deafferentation and oedema.