Figure 4.
Synapsin associates with recycling SVs in growth cones. a-b″, Double immunofluorescence of rat hippocampal neurons stained with antibodies against synaptotagmin I (b; green in a and b″) and synapsin I (b′; red in a and b″). Synapsin I colocalizes with synaptotagmin I in a subpopulation of SVs in the growth cone and at virtually all synaptic varicosities along the axon (a, arrowheads). c-c″, Neurons were incubated with the SytL antibody (c; green in c″) in KRH for 15 min at 37°C, fixed, and counterstained with an antibody against synapsin I (c′; red in c″). Synapsin I associates with SytL-positive (i.e., recycling) SVs. Scale bar: (in a) a, 10 μm; b-c″, 5 μm.