Fig. 1. Simultaneous visualisation of granules and cytoplasmic structures by confocal scanning microscopy. Granules were detected in quinacrine-treated chromaffin cells by epifluorescence whereas cytoplasmic structures were evident in the transmitted light channel implemented in an Olympus Fluoview FV300 microscope incorporating a 100 x LUMPlan FI water-immersion objective. (A-D) Images of four planes separated by 1.0 µm along the Z axis. Structure density increased in the region beneath the plasmalemma forming a peripheral ring and extending into the cytoplasm with the appearance of polygonal cages. The nucleus presents a less defined blurry organisation. (E) Vesicle fluorescence and optical density of the transmitted light image across the line depicted in C. Vesicles accumulate in the proximity of the peripheral ring visualised by transmitted light scanning microscopy. (F) Cross-sectional images of transmitted light structures in a chromaffin cell in the conventional X-Y plane and two X-Z and Y-Z cytoplasmic planes (indicated by coloured lines in the X-Y section). (G) 3D reconstruction of a portion of the cytoplasmic structures showing an intricate network. Black surfaces represent solid structure. Bar, 10 µm (A-D); 2 µm (F); 1 µm (G).