Biomedical subjects
Publications and source records attributed to M Matteoli.
Explore the source record for details and available documents.
The time course of the reaction to axotomy in the leech AP cell was determined by measuring the duration of the spontaneous spikes at different times after the operation. The axotomy performed by section of the segmental roots containing the AP axon induced an increase of the spike duration, which persisted over 30 days. A different time course was found when the axotomy was performed by nerve crush: the changes in duration of the spontaneous spikes, which occurred during the early 2 weeks, were significantly reduced afterwards. Dye staining of some cells axotomized by crushing revealed that the reversion of the changes, which had been set up by axotomy, was in some cases concomitant with the reconnection between proximal and distal axon stumps. The section of a single axonal branch was never sufficient to affect the membrane properties of the AP cells. It is concluded that the changes observed in axotomized AP cells are not produced by simple axonal injury and that the maintainance of normal properties in the somatic membrane requires the presence of at least part of the distal axon arborization.
An identified neuron of the leech central nervous system is affected by the application of colchicine or vinblastine to its axon. It develops characteristic changes of membrane electrical properties, which are similar to those observed after surgical axotomy. The ionic mechanisms associated with the impulses induced by axotomy and colchicine treatment are not equivalent.
Membrane properties of identified leech neurons with non-spiking somata were studied after axotomy. Two distinct procedures were used: the section of ganglionic roots in vivo and the isolation of cell somata in culture. The results indicated that axotomized neurons progressively developed the excitability of somatic membrane, both in vivo and in culture.
Explore the source record for details and available documents.