Anterograde and Retrograde Transneuronal Degeneration in the Central and Peripheral Nervous System
Although it has been known for more than half a century that certain groups of neurons may atrophy, or degenerate, following the death of the cells upon which they project or after the interruption of their afferents, it is not generally appreciated how widespread such transneuronal changes may be. As recently as 1956 Torvik, in a study of the effects of lesions in the brainstem and cerebral hemisphere upon the inferior olive and pontine nuclei, could state: “In adult animals it seems questionable whether transneuronal changes appear at all in other areas than the lateral geniculate body ”. However, even at that time there was a considerably body of evidence, both experimental and clinico-pathological, to indicate that both types of transneuronal degeneration — that following deafferentation and that secondary to retrograde cell degeneration — may occur in a number of neuronal systems. And since the publication of Torvik’s paper there have been a number of additional studies which have served to emphasize the widespread occurrence of transneuronal effects both in the central and peripheral nervous systems. The etiological factors responsible for the atrophy or degeneration of neurons which have suffered no direct injury are still largely unknown, but nevertheless the time seems opportune to review the now extensive literature on this subject.
KeywordsMigration Hydrocarbon Shrinkage Retina Peri
Unable to display preview. Download preview PDF.