Precisely what makes the motor neurons degenerate is the prevailing mystery of ALS.

使运动神经元退化的原因正是ALS的流行之谜。

GAD helps make gamma-aminobutyric acid (GABA), which regulates motor neurons in the brain.

谷氨酸脱羧酶有助于制造γ-氨基丁酸（GABA），它调节大脑中的运动神经元。

If this reflex is absent, it could indicate that you have a lower motor neuron problem.

如果这种反射不存在，它可能表明你的下部运动神经元有问题。

This tightness results from a lesion in an upper motor neuron.

这种僵硬由上运动神经元损伤引起。

So, contractions intensify as your motor neurons stimulate more and more muscle fibers.

所以，当你的运动神经元刺激越来越多的肌肉纤维时，收缩会加剧。

ALS affects two types of nerve cells called the upper and lower motor neurons.

ALS影响两种类型的神经细胞，称为上下运动神经元。

One prevailing idea is that certain proteins inside the motor neurons aren't folding correctly, and are instead forming clumps.

一个主流想法是运动神经元内的某些蛋白质没有正确折叠，而是形成团块。

We've also learned that along with motor neurons and muscle fibers, ALS could involve other cell types.

我们还了解到连同运动神经元和肌肉纤维，ALS可能还会涉及其他细胞类型。

Defective immune cells may also play a role in killing motor neurons.

有缺陷的免疫细胞也可能在杀死运动神经元中发挥作用。

Meanwhile, at the level of lesion, the lower motor neuron of the right ventral horn will also be damaged.

同时，在病变水平，右侧脊髓前角的下运动神经元也会受到损伤。