Objective

Characterization of the nerve components by deuterium double quantum-filtered magnetization transfer (DQF-MT) NMR.

Methods

Nerves were equilibrated in deuterated saline and ²H single-pulse and ²H DQF-MT NMR spectra were measured, enabling the separation of the different water compartments, according to their quadrupolar splittings.

Results

Rat sciatic and brachial nerves and porcine optic nerve immersed in deuterated saline yielded ²H DQF spectra composed of three pairs of quadrupolar-split signals assigned to the water in the collagenous compartments and the myelin bilayer and one narrow signal assigned to the axonal water. Stretching of the nerves, application of osmotic stress and incubation in collagenase did not affect the quadrupolar splitting of the myelin water. The signals of myelin and axonal water were shown to decay during Wallerian degeneration and to rise during maturation. The chemical exchange between the myelin and the intra-axonal water was measured for optic nerve during maturation. The quadrupolar splitting of the signal of myelin water was not sensitive to its orientation relative to the magnetic field. This resembles liquid crystalline behavior, but leaves its mechanism open for interpretation.

Conclusions

²H DQF-MT NMR characterizes the different components of nerves, the water exchange between them and their changes during processes such as nerve maturation and Wallerian degeneration.

中文翻译：

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外周和视神经的氘双量子过滤核磁共振研究

客观的

通过氘双量子过滤磁化转移 (DQF-MT) NMR 表征神经成分。

方法

神经在氘化盐水中平衡，并测量了² H 单脉冲和² H DQF-MT NMR 光谱，根据它们的四极分裂，能够分离不同的水室。

结果

大鼠坐骨臂神经和猪视神经浸泡在氘化盐水中产生²H DQF 光谱由分配给胶原隔室和髓磷脂双层中的水的三对四极分裂信号和分配给轴突水的一个窄信号组成。神经的伸展、渗透压的应用和在胶原酶中的孵育不影响髓磷脂水的四极分裂。髓鞘和轴突水的信号在沃勒变性期间衰减并在成熟期间上升。在成熟过程中测量视神经髓鞘和轴突内水之间的化学交换。髓鞘水信号的四极分裂对其相对于磁场的方向不敏感。这类似于液晶行为，但其机制尚待解释。

结论

² H DQF-MT NMR 表征了神经的不同成分、它们之间的水交换以及它们在神经成熟和沃勒变性等过程中的变化。