Ultrastructure of capitate projections in the optic neuropil of Diptera.

摘要: Photoreceptor axons in the first optic neuropil of dipteran flies Musca domestica and Drosophila melanogaster was examined with electron microscopy. The objective to determine ultrastructure, persistence glial source capitate projections found within these neurons. Capitate are simple or compound processes epithelial cells which profusely insert into form-fitting folds axon terminals peripheral retinular (R1-6) synaptic plexus portion neuropil. These neuro-glial junctions may be indentations, have a head single stalk, possess single, circular stalk from 3 4 bulbous (glial) heads elaborated. Using serial thick sections for HVEM we were able observe that stalks connecting nearly all led directly cell. Thus no disembodied suspended axoplasm. appeared persistent structures, present young as well senescent adults. No evolution form found; thus distinct expressions (without transitional forms) present. From freeze-fracture replicas it determined there approximately per micron 2 Musca, respectively. About 800 exist terminal about 5 times number chemical synapses. Cp's slightly larger than although has twice diameter length fruit fly. evidence reviewed light likely supportive function on R1-6 terminals.