Fig. 7.

Immunofluorescent localization of the endomembrane system in hippocampal neurons in culture. Fourteen-day-old neurons were fixed and stained for markers of the ER and GA. A, Localization of the rough ER protein ribophorin I. Note the accumulation of stained ER structures at branch points (asterisks) as well as the absence of label in some dendritic branches (open circles). Axons (open triangles) remained unlabeled. g indicates glial cell. C, Distribution of the medial cisterns of the GA as revealed by α-mannosidase II staining. As is evident, immunostained elements extended into dendrites; indeed, they have a similar subcellular distribution as the immunostaining for the RER. Dendrites (arrows) were identified by double staining for MAP2 (B, D). Scale bars, 50 μm.