Fig. 4.
A, Autoradiogram of a synaptosomal fraction after incubation with [3H]leucine. Silver grains have both a clustered and a dispersed distribution. The background of the photographic emulsion is shown in the bottom left corner for comparison. B, Cycloheximide abolishes the response, because clusters and dispersed silver grains are virtually absent. The background is shown in the bottom right corner. In both A and B the underfocused synaptosomes appear as ghosts. Magnification, 600×. Scale bar, 20 μm.