Our objectives were to examine the effects of temperature upon slow axoplasmic transport in crushed and intact sciatic nerves of hibernating and nonhibernating ground squirrels ( Spermophilus tridecemlineatus). Tritiated leucine was injected into the spinal cord near the ventral horn cells of the sciatic nerve and, after protein incorporation, allowed to transport for 5, 10, 15, or 20 days. Slow transport profiles were obtained from crushed and intact sciatic nerves of hibernating and nonhibernating animals. No significant differences ( P < 0.05) were demonstrated in the transport velocities between crushed and noncrushed nerves in either hibernating or nonhibernating ground squirrels. Furthermore, no significant differences were found in transport velocities between hibernating and nonhibernating groups of animals. Slow axoplasmic transport velocities are not only unaffected by crush injury in this system, but also unaffected by normally lethal temperatures. This suggests that the slow component in the nerves of hibernating animals may be responsible for maintaining neurotrophic control throughout hibernation. The data also suggest that different mechanisms may be involved in slow versus fast axoplasmic transport.