MENINGEAL CELLS STIMULATE NEURONAL MIGRATION AND THE FORMATION OF RADIAL GLIAL FASCICLES FROM THE CEREBELLAR EXTERNAL GRANULAR LAYER

The cerebellar granule cell layer and partly the Bergmann glial scaffo ld arise from a secondary subpial proliferative zone, the external gra nular layer. Their development can be disrupted by selective destructi on of meningeal cells. In order to clarify the mechanisms of meningeal control of cortical development, we have investigated the development of early postnatal rat cerebellar slice explants in different cocultu re set-ups with meningeal cells and other fibroblasts. Fibroblasts of various sources (1) stimulate migration of undifferentiated neurons fr om the explants by a diffusible factor and (2) trigger the development of a radial phenotype in glial cells by contact-mediated mechanisms i nvolving basal lamina constituents. These data provide further evidenc e for the involvement of mesenchymal-epithelial interactions in the de velopment of the cerebellar cortex. (C) 1998 Elsevier Science Ireland Ltd.