REGENERATION OF MONO-AMINERGIC AND CHOLINERGIC NEURONS IN THE MAMMALIAN CENTRAL NERVOUS-SYSTEM

There is now evidence that true axonal regeneration occurs in the central nervous system of some mammalian species. There are at least 3 different mechanisms by which regenerative sprouting can become functionally relevant: regrowth of part of the sprouting fibers to their target sites; collateral sprouting from intact axons; alternative intact pathway, which normally does not share function with the lesioned pathway, can be made to mediate the function of the severed system through a readjustment of neural connections. Much of the research during recent years has suggested that different types of central neurons may differ considerably in their reactions to injury, especially in the adult central nervous system. The mechanisms regulating sprouting and regrowth of the monoaminergic and cholinergic neurons do not differ markedly from those controlling regeneration of other nonmyelinated axon systems in the brain and spinal cord. (Wozniak - Poznan)