The distribution of the synaptic vesicle-associated phosphoprotein synapsin I after electrical stimulation of the frog neuromuscular junction was investigated by immunogold labeling and compared with the distribution of the integral synaptic vesicle protein synaptophysin. In resting terminals both proteins were localized exclusively on synaptic vesicles. In… (More)
By the use of anti-omega-CTx antibodies in indirect immunofluorescence we demonstrated the presence of omega-CTx binding sites in the presynaptic compartment of frog nerve-muscle preparations. The images we obtained indicate that omega-CTx-sensitive channels are clustered at discrete sites corresponding in distribution to active zones.