抄録
Degeneration of neurofilaments is considered as the marker of Wallerian degeneration of peripheral nerves. It is also true that neurofilaments are the first to regenerate when the regeneration process begins. Presently, the neurofilaments can only be detected by destructive methods such as electron microscopy and biochemical methods. In this report, we propose H-2 double-quantum filter (DQF) NMR as a potential technique to measure the neurofilaments non-destructively. The signals of water in the epineurium, endoneurium, and axon of sciatic nerve are resolved in the H-2 DQF NMR spectrum, due to their different quadrupolar splittings (V), and the dependence of the DQF signal intensity of each of the signals on the creation time (τ) of their DQ coherences. We have observed the Wallerian degeneration of rat sciatic nerve for 4 days, and measured signal intensity of the DQF spectrum of the intraaxonal water compartment. The intensity of the intraaxonal signal (V= 9 Hz at τ= 30 ms) started to decrease 24 hrs after the incision, and almost disappeared at day 4. The remaining signal observed is mostly that of the water in the epineurium, which has its maximal value at τ of 3 ms. The time-course of the degeneration as detected by H-2 DQF NMR agrees well with the TEM images obtained by Jeol JEM-1200EX also confirmed the degeneration process of the neurofilaments. From these results, we can conclude that H-2 DQF NMR can be used to quantify the degeneration process of the neurofilaments in the axon. [Jpn J Physiol 54 Suppl:S64 (2004)]
