Geometry of neonatal neurones and the regulation of synapse elimination
In the ciliary ganglion of adult rabbits, ganglion cells lacking dendrites are generally innervated by a single axon, whereas cells with one or more dendrites are innervated by a number of different axons that increases in proportion to the complexity of their dendritic arbor. We have now explored the basis of this correlation by comparing the dendritic arborization of cells receiving different numbers of axons during and after the period of synapse elimination that occurs early in postnatal life. Our results suggest that the geometry of neonatal neurones influences the competitive interaction between the several axons that initially innervate the same cell. This finding in turn implies that an important function of dendrites is to regulate the number of different axons that ultimately innervate each neurone.