Novas observações sôbre as fibras nervosas que repopulam o segmento distal de nervos com mais de seis meses de secção completa

Abstract

The scope of this paper is to present and discuss the different histological findings, recently reported by us before the VIII International Congress of Anatomists, Wiesbaden, Germany and the V International Congress of Neuropathology, Zurich, which were identified among the nerve-fibres that repopulate the distal and intermediate segments of nerves, maintained undisturbed in their natural connective tissue bed, and completely separated from the proximal stump for more than six months (Erhart and Erhart 6 . 7 , Erhart 8 , Erhart and Rezze 9, . 10,11 ).The above referred histological findings resemble some of the progressive stages of the Wallerian degeneration and, for what we have seen in our experimental observations, they show up as a suggestive sequence of stages which seem to indicate a possible gradual reorganization and further regeneration of nerve-fibres in isolated stumps. MATERIAL AND METHODSThe serial histological preparations, longitudinally sectioned 8 u, silver impregnated by De Castro, considered in the present report were selected from the material we have recorded and analised during these last nine years while studying the nerve fibres which repopulate, under different experimental conditions, the distal and intermediate segments of dog fibular, intercostal, phrenic and ulnar nerves completely separated from the proximal stump for more than six months. Obviously the slide selection was based on the presence of the particular histological pictures in which we were interested. They were identified in the intermediate and or distal nerve segments of eleven different dogs. RESULTSWhile studying the nerve fibres which repopulate, under different experimental conditions, isolated nerve segments, we observed now and then in the silver preparations, six and eight months post-operatively, among the nerve fibres with