GANGLI SPINALI IN COLTURA: SVILUPPO DI UN MODELLO PER LO STUDIO DELLE INTERAZIONI TRA NEURONI E CELLULE GLIALI

DRG neurons are pseudo-unipolar primary sensory neurons with a peripheral axon branch projecting towards selective sensory organs and a central axon branch projecting in the direction of spinal cord. The neuron bodies are surrounded by satellite glial cells which form numerous sheaths. Based on laboratory protocols and several years of practical experience with primary cell culture, the present study had been conducted to find a model system in which co-culturing DRG neurons and SGC cells. Ganglia were dissected from adult rats and cells were cultured in two different media to examine the possible differences. In this way it was possible examining the relationships between these kinds of cell. Thanks to these work it has been shown the importance of glial cells and their factors for DRG neurons axonal regrow (after a lesion for example). In particular it has been shown the peculiar reaggregation between these cells in vitro, in complex circular clusters. The influence of a NGF treatment on the relationship formation has been investigated: the neurotrophic factor seemed to speed up the aggregation. Apart from immunocytochemistry procedures, a time lapse analysis has been conducted to follow the aggregations during their formation. Finally the functionality of these clusters has been examined utilising marker against synaptogenesis molecules. The expression of presynaptic vesicle proteins has been confirmed. These results induced to hypothesize a possible tissue memory which led cells to aggregate, restoring the interactions which originally linked neurons and glial cells in vivo. An hypothetical tissue memory is particularly surprising because of the employment of adult rat cells. The results also suggested many future experiments and some of these are already in progress.