Figure 4.

The chronology of loss of labeling of axonal neurofilament and its restoration in rat soleus muscles after the inoculation of a single dose of β-BTX. By 3 hours, only 40% of junctions were innervated by axons with an intact cytoskeleton; most axons exhibited a fragmented cytoskeleton. By 6 hours, labeling was continuous in only 9% of axons. No continuous labeling was seen at 12 hours, and labeling was non-existent at 24 hours. At 120 hours, all junctions were innervated by axons with an intact cytoskeleton, but axons were thin and wispy and many exhibited both pre- and post-terminal sprouts. Cytoskeleton labeling was normal by 14 days. Each point represents data from 92 to 238 junctions visualized in muscle fiber bundles obtained from three soleus muscles.