Effect of tissue temperatures and blood flow on motor nerve conduction velocity.

The existence of a relationship between peripheral nerve conduction velocity and ambient temperature is supported by considerable experimental evidence. 1-5 For example, Rosenberg and Sugimoto 1 exposed the sciatic nerve of frogs to a temperature range of 78.8 to 38.3 F (26 to 3.5 C) and noted that, on the average, conduction velocity decreased from 33 meters/sec to 6 meters/sec, the change occurring slowly above 53.6 F (12 C) and rapidly below this level. Gasser, 2 using the phrenic nerve of the dog, also showed that cooling this structure decreased its conduction velocity. Chatfield et al 3 subsequently performed a similar type of procedure on the tibial nerves of rats and hamsters and came to the same conclusion. Tasaki and Fujita, 4 studying the isolated single nerve fiber of the toad, found that the relationship between the ambient temperature and the logarithms of conduction time, spike duration, and chronaxie for