Kobayashi J, Ohta M, Terada Y
Department of Prosthetic Dentistry I, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
Neurosci Lett. 1993 Nov 12;162(1-2):93-6. doi: 10.1016/0304-3940(93)90568-6.
The present study was carried out to examine the properties of A and C fibers in the bullfrog sciatic nerves by applying several agents through perfusing solutions between stimulating and recording electrodes. The compound action potentials (CAPs) of A beta and A delta fibers were tetrodotoxin (TTX)-sensitive and were abolished in Na(+)-free solution. However, C fiber CAP was TTX-insensitive although CAP disappeared in Na(+)-free solution. Moreover, C fiber CAP was not blocked by Ca2+ channel blockers and its chronaxy (2 ms) and conduction velocity (0.70 m/s) indicate that the time constant of C fiber CAP is relatively large (2.88 ms). These suggest that a slow Na+ channel, which is TTX-resistant, contributes to C fiber action potentials.
本研究通过在刺激电极和记录电极之间灌注溶液应用多种试剂，来检测牛蛙坐骨神经中A纤维和C纤维的特性。Aβ纤维和Aδ纤维的复合动作电位（CAPs）对河豚毒素（TTX）敏感，且在无钠溶液中消失。然而，C纤维CAP对TTX不敏感，尽管在无钠溶液中CAP消失。此外，C纤维CAP不被钙通道阻滞剂阻断，其时值（2毫秒）和传导速度（0.70米/秒）表明C纤维CAP的时间常数相对较大（2.88毫秒）。这些表明一种对TTX有抗性的慢钠通道参与了C纤维动作电位的形成。
