Figure 7.

Synapsin movement between boutons is enhanced upon stimulation. Black symbols, Preparations at rest; red symbols, preparations where patterned depolarization was used immediately after photobleaching. A, Syn-eGFP fluorescence recovers by 30–40% within 45 min after bleaching (arrow) in stimulated preparations. Only “central” boutons were included in this analysis, i.e., those located along the branches but not at the branch endings. Nonstimulated preparations show only mild recovery (<10%). Stimulation significantly enhances recovery (p < 0.01 per 2-way ANOVA, n = 8 per condition). B, Terminal boutons (those located at the branch endings) do not show Syn-eGFP recovery after photobleaching, either in the presence or in the absence of stimulation (nonstimulated, n = 7; stimulated, n = 9). C, When three adjacent boutons are bleached, the central bouton of the three shows no recovery in the absence of stimulation and very mild (<10%) but significant (p < 0.02 per 2-way ANOVA) recovery upon stimulation (nonstimulated, n = 9; stimulated, n = 7).