Conduction coding of nonmyelinated fibers in rabbit saphenous nerve
AIM: To investigate the conduction coding during the course of action potential (AP) propagating along nonmvelinated nerve fibers. METHODS: Single C fiber of saphenous nerve was separated and then stimulated repetitively by 200 trains of quintuplets superthreshold electrical pulses at a certain interstimulus intervals(inter-stimulus interval 1 s, stimulus interval 20 ms, 5 pulses/train). The AP was recorded and the interspike interval(ISI) was calculated, and the patterns of ISIs during the course of AP propagating were observed. RESULTS: During the course of AP propagating along C fibers, no conduction failure was observed, but patter of ISIs changed. According to the difference between interstimulus and intersipike intervals, ISI had three phases. Phase-1: ISI was longer than interstimulus interval. ISI increased from 20 to 24 ms; Phase-2: ISI equaled to intestimulus interval; and Phase-3: ISI decreased to 8 ms and then reached a stable value of about 10 ms. CONCLUSION: Patterns of ISIs change when APs propagate along the nonmyelinated fibers, suggesting that C fibers have the ability to code the signals propagating along axon by the variance of ISI.
NETL
NSTL
万方数据
维普
