Abstract EN:

The aim of this study was to investigate 1) the regulation of PSA-NCAM expression and the synaptogenesis during postnatal development of dorsal vagal complex (DVC), 2) how synaptic activity, using vagal afferents stimulation can regulate PSA expression. The DVC is a gateway for many primary afferents and participates in the maintenance of homeostasis. The polysialyted form of the neural cell adhesion molecule (NCAM) has been implicated in many aspects of cell-cell interactions and multiple forms of plasticity. We examined PSA-NCAM expression pattern during postnatal development and in adult rat DVC. During the first postnatal week, PSA expression is5 ubiquitous in all medulla regions and becomes restricted to the DVC in adult rat. We determined the effect of electrical stimulation of vagal afferents on PSA both in vivo and in acute slices. Before P15, afferent activity induces a rapid up-regulation of PSA expression. In contrast, after P15, the same paradigm induces a rapid and time-dependent decrease in PSA expression. These results confirm that maturation and synaptogenesis continue to occur during the first postnatal weeks within thr DVC. We demonstrated that at all stages examined, NMDAR activation is required for regulation of PSA expression.