Article révisé par les pairs
Résumé : The development of granule cells and their connections was reinvestigated in organotypic cultures of cerebellum. Modified Golgi‐Cox preparations showed numerous maturing granule cells, some with fully mature claw‐shaped dendritic endings, within presumptive cortex. Large cortical neurons often had dendrites richly encrusted with synaptic spines. Sometimes bundles of thin parallel processes were oriented orthogonally to the spiny dendrites. Semithin sections and electron micrographs showed granule cell somas distributed in closely packed clusters, with directly apposed cell membranes. Several types of glio‐glial membrane apposition were observed, including extensive desmosome‐like junctions. The neuropil contained closely packed bundles of thin parallel processes and numerous synaptic complexes, often within the parallel bundles. The postsynaptic elements, when identifiable, often proved to be dendritic spines; axodendritic and axosomatic synapses were less common than axospinous. A few synaptic complexes resembled glomeruli, with linked granule cell dendrites surrounding a presynaptic element. The concurrence of several lines of evidence proves the identity of granule cells in presumptive cortex, but the existence of basket and Golgi Type II neurons and the source of presynaptic element in the glomerulus cannot be demonstrated. The criteria and importance of rigorous cell identification in cultures are discussed. Copyright © 1970 The Wistar Institute of Anatomy and Biology