Nodal changes during the early stages of Wallerian degeneration of central nerve fibres.

The nodal changes in central nerve fibres undergoing Wallerian degeneration have been studied during the first 48 hr after section of the dorsal columns of the rat by single fibre teasing and by conventional light and electron microscopic techniques. The earliest changes found at 24 hr consisted of an accumulation of mitochondria, other organelles and lamellar bodies in the nodal axoplasm. Attenuation of the myelin sheath on one side of the node due to detachment of terminal myelin loops and slipping of the outer myelin lamellae was found in some fibres, and varying degrees of nodal widening in others at 24 hr. The functional significance of these early changes in the nodal region is uncertain.