Figure 3. The peripheral distribution of both synapsin and vesicles is disrupted after CycA pretreatment.
A-D. Immunolabeling for synapsin (A) shows that it is distributed over the periphery of the bouton, similar to FM1-43 staining (B) at a mild stimulation paradigm (5 min at 3 Hz). After CycA pretreatment, both synapsin (C) and FM1-43 (D) fluorescence becomes distributed over the entire bouton, spreading towards its central core.
E. A representative electron micrograph showing a bouton after CycA pretreatment and mild stimulation (5 min at 3 Hz). Note that vesicles are distributed over the entire bouton, including its central core.
F. Quantitative analysis shows that after a CycA treatment followed by a mild stimulation, synapsin (left column) or vesicles disperse and occupy larger areas than at rest. This does not occure in synapsin (−) boutons (right column). Synapsin immunostaining data are collected from 8 CycA untreated preparations (31 bouton) for and 5 CycA treated preparations (18 boutons). EM data collected from 3 preparations (15-20 boutons) for each line at each condition.