Ultrastructural studies on synaptic formations in dissociated fetal mouse brain cultures.

Sequential electron microscopic studies of cultures of neurons derived from dissociated fetal mouse brain on the eleventh day of gestation revealed the formation of well-developed synapses during the second and third weeks of growth in vitro. Synaptic junctions were associated with synaptic vesicles nd dense synaptic membranes. Dense-core vesicles were also observed frequently in presynaptic terminals.