Figure 4. VAMP-2 is expressed at conventional synapses in the mouse retina

Double-labeling for VAMP-2 and synapsin I (SYN I), a marker for conventional synapses (Mandell et al., 1990). Labeling for VAMP-2 is prominent in synaptic terminals in both the OPL and IPL. Strong labeling for synapsin I is present in conventional synapses in the IPL and sparsely distributed conventional synapses in the OPL (arrows), which also show labeling for VAMP-2. Synapsin I labeling is absent from the ribbon synapse-containing photoreceptor terminals and a set of large terminals along the inner border of the IPL corresponding to the rod bipolar cell terminals (small arrowheads). Weak labeling for VAMP-2 and synapsin I is also visible in the cell bodies of some amacrine cells (a) and presumptive displaced amacrine cells (da). Scale bars represent 20 μm.