Fig. 3. ER, mitochondria and synaptic vesicles. (A) Colocalisation of ER and synaptic vesicles. The uppermost panel shows the merged images of Mag-Fura-2 (red) and FM 1-43 (green). The overlap between images was 25% (mean 27±6% in six cells). The middle panel presents the fluorescence profiles in the dendrite which indicate positions of ER vesicles (red) and synapses (green). The lowermost panel shows the mean profiles obtained by averaging the data in 15 ROIs that contained both ER and synaptic vesicles. (B) Mitochondria and synaptic vesicles. The uppermost panel shows the images of TMRE (red) and FM 1-43 fluorescence (green). In this image, the coincidence of pixels that corresponded to the positions of mitochondria and synapses was 24% (mean 27±5% in seven cells). The lower graphs show the linescans in dendrites and corresponding mean profiles obtained from 18 ROIs where the positions of synaptic vesicles overlapped with those of mitochondria. (C) Colocalisation of mitochondria and ER vesicles presented as an overlay of Mag-Fura-2 (green) and TMRE images (red). The overlap between positions of ER vesicles and mitochondria in this neuron was 34% (mean 37±6% in seven cells). The middle and the lowermost graphs show respectively the linescans along dendrites and the mean profiles that were obtained by averaging the data for 16 pairs of particles. Bar in all upper panels, 10 µm.