Fig. 2. Roscovitine increases the translocation of biotin-L into axons. DRG neurons were injected with a mixture of biotin-L and fluorescein-conjugated tracer. Following a 2 hour incubation, cells were fixed and processed for biotin immunoreactivity. Injected cells were located by fluorescein tracer and the distribution of biotin-L (arrows) was then monitored. Micrographs present images of representative neurons, arrows denote axons. The accompanying graph presents a densitometric analyses of the proportion of biotin-L (mean densitometric value ± standard error of the mean) in perikarya from multiple neurons. Notice the marked decrease in levels of biotin-L in in perikarya of neurons treated with roscovitine, indicative of increased translocation into axons.