Degeneration and Regeneration of Neurosecretory Systems

Abstract

Publisher Summary Degenerative and regenerative phenomena have substantially contributed to the knowledge of neurosecretory systems. The general structural organization, the degeneration, and regeneration of neurosecretory neurons, and the process of neurosecretion are identical throughout the animal kingdom. In the first phase after interruption of a neurosecretory axon, the proximal and distal stumps react identically with the development of a dense system of tubular formations and with an increase in other axoplasmic organelles conveyed to the stumps from more proximal or more distal portions of the axon. During the second phase growth, cones containing numerous tubular formations and vesicles start to sprout from the axon in the proximal stump as an initiation of regeneration. The third phase in the proximal stump leads to the progressive establishment of new axon terminals in contact with a newly developed vascular plexus; these terminals are identical to those observed in the normal neural lobe.