Figure 3.

Sensory neuron axons display localized LTH after peripheral nerve injury, and this LTH depends on local protein synthesis. A, Responses recorded in the soma while testing axon spike threshold and repetitive firing before and 24 hr after crushing nerve p9. B, Nerve crush in normal saline significantly decreased axon spike threshold for 50 msec test pulses delivered close to (0.5-1.5 mm away) but not distant from (2-4 mm) the crushed (Cr) site. Asterisk indicates significant difference (Dunnett's test) relative to uncrushed (Uncr) control group. C, Nerve crush in low-Ca saline also decreased spike threshold. D, Crush-induced (in low-Ca saline) decrease in spike threshold was prevented by local application during the crush of protein synthesis inhibitors, anisomycin (10 μm; Aniso) or rapamycin (20 nm; Rapa). In both C and D, asterisks indicate comparisons with the crushed (Cr) group in C (Dunnett's tests).