GM2 is found mainly in neurons, so without HEX-A, it accumulates inside lysosomes.

GM2通常分布神经元，因此如果HEX-A缺失，GM2就会溶酶体。

Also, between the circular and the longitudinal muscle layer, there's a plexus, or networks of nerves, which help coordinate muscle contraction and relaxation.

另外，内环肌和外纵肌之间，还有神经丛（神经络）的分布；神经丛可以协调肠道平滑肌的收缩与舒张。

In the thoracic region of the spine, neural crest cells differentiate into the neurons of the sympathetic chain, lying on either side of the entire spinal cord.

柱的胸椎节段，神经嵴细胞分化成交感神经链的神经元，分布整条髓的两侧。

That's the stage when individuals usually experience pain, although pain can also occur when the caries lesion involves the dentin layer since sensory nerve fibers travel through tubules in the dentin.

这个阶段，患者常会感到疼痛，但牙本质层受累产生龋坏时也可能有疼痛产生，因为感觉神经也分布牙本质的管道。