摘 要 本研究主旨在探討大鼠坐骨神經電傳導性與拉伸變形的關係,實驗所使用的老鼠品種是 Long-Evan,而使坐骨神經產生變形的方式則是採取拉伸及固定應變兩種實驗。在拉伸實驗中應變速率為 0.0083 與 0.083 s-1。其結果顯示,在兩個不同應變速率下,神經的電傳導性並沒有顯著的差異,且神經電位減少的程度取決於應變的大小而與應變速率無關。在固定應變實驗方面,在三個不同的應變量下 (50%、80%、95%) ,我們發現較高的應變 (95%) 會有最低程度的神經電位衰減以及最少的殘留神經電位;同時也發現在固定應變下神經電位有持續減少的現象發生,此現象顯示大鼠坐骨神經電位,在固定的應變下,和變形造成的傷害有相當大的關係,而與應力大小程度較無直接關係。最後,本研究使用 Boltzmann equation 來分析神經電位與拉伸應變之關係,結果顯示 Boltzmann equation 有相當不錯的描述效果。
ABSTRACT The present study was conducted to investigate the relationship between the in vitro nerve-impulse conduction and applied tensile deformation in sciatic nerves of Long-Evan rat under increasing and constant elongation test. Results showed that the nerve-impulse conduction during increasing elongation test (tensile test) was of no significant difference between two given strain rates, 0.0083 and 0.083 s-1. Such results indicated the compound nerve action potential (CNAP) amplitude drop was dependent on the strain level and independent of strain rate. During constant elongation (stress relaxation) test, a higher constant strain (95%) would generate a lower final CNAP amplitude ratio but a smaller extent of CNAP amplitude drop, compared to the lower constant strain levels (50% and 80%). The continuous drop of CNAP amplitude during stress relaxation under constant deformation implied that the nerve-impulse conduction in rat sciatic nerve was dependent on the development of deformation-induced damage rather than on the stress level. Finally, the relationship between CNAP amplitude ratio and strain under increasing elongation test could be well described by a Boltzmann equation.