Fig. 1

Synaptic vesicle dynamics in individual large MF boutons (LMFBs) in the hippocampus. a A synaptopHluorin (SpH) fluorescence image of an acute slice of TV-42 transgenic mouse hippocampus. The MFs were stimulated at the dentate hilus (right) and recorded from the distal CA3 region (left square). b An enlarged view of the stratum lucidum included in the square in a. Individual LMFBs are identifiable by the SpH fluorescence in the plasma membrane. c A sample averaged image of the SpH fluorescence of LMFBs before nerve stimulation. d Similar to c, but the images were sampled near the end of repetitive stimulation of 10 Hz for 10 s. e The digital subtraction of both images (difference image). The magnitude is shown as a pseudocolor rating. f Time-dependent profiles of SpH fluorescence signals of the ROIs indicated in e. The stimulation period is indicated by a red stripe. g Average SpH signal profile of sample records in f. Note that the fluorescence intensity steadily increased during repetitive stimulation, but recovered to the baseline after the cessation of stimulation