“the only interesting thing about vertebrates is the neural crest” (Thorogood 1989)
前篇：名词解释 | Hedgehog signaling pathway | Hh | 刺猬
学习发育生物学得有非常好的空间想象力，一切都处于动态的变化当中。
教材定位：Developmental Biology - Building with Ectoderm: The Vertebrate Nervous System and Epidermis - Chapter 15 Neural Crest Cells and Axonal Specificity
结合肠道发育和肠道疾病一起学习：
Neural Crest - Enteric Nervous System
Neural Crest and the Development of the Enteric Nervous System
Chapter 12 - Neural Crest Cells in Enteric Nervous System Development and Disease
附加阅读：Ablation of Ezh2 in neural crest cells leads to aberrant enteric nervous system development in mice
neural crest cell很多种，我们这里特别关注ENCC。
this migration takes a long time—over 25% of the gestation period for mice and around 3 weeks in humans.
There are many different classes of enteric neurons that differ in their neurotransmitters, electrophysiological properties, targets (circular muscle, longitudinal muscle, other neurons, blood vessels, epithelium etc), inputs and the direction along the gut in which their axons project.这些neuron是如何行使功能的。
The neurons are grouped into ganglia, and each ganglion contains many different types of neurons. Myenteric ganglia are located between the circular and longitudinal muscle layers, and submucosal ganglia are located internal to the circular muscle layer.
搞清楚肠道的胚胎发育过程。
ENS is derived from crest cells that originate from two specific regions of the neuraxis – the vagal (defined as post-otic hindbrain adjacent to somites 1-7) and sacral (caudal to somite 28 in chick embryos and caudal to somite 24 in embryonic mice and humans) levels6 (Fig. 1).
In mice, vagal neural crest cells migrate underneath the epithelium, through the somites, between the somites, and between the somites and the neural tube
Vagal neural crest cells enter the nearby foregut mesenchyme at the 20-25 somite stage
Once in the foregut, vagal neural crest cells migrate caudally along the entire length of the gut (Figs. 1, 2).
In mice (Fig. 2A-C), the colonization of the gut by vagal neural crest cells takes around 5 days; crest cells enter the foregut around E9.5; reach the cecal region at E11.5 (Fig. 2B); and completely colonize the gut by E14.5.28 In humans, vagal neural crest cells enter the foregut at week 4 and reach the terminal hindgut by week 7.
Thus, even in the rectum, the vast majority of enteric neurons arise from precursors that originate in the hindbrain (vagal crest cells).
搞清楚成熟肠道的纵截面结构：如mucosal epithelium、mesenchyme等。
解剖学的上下左右前后的英文要彻底搞清楚：如caudal、dorsal、ventral等。
肠道各个部位的叫法：如rectum、hindgut等。
三个皮层、三个derm：ectoderm。
参考：
Neurology | Enteric Nervous System
The development of the nervous system
Embryology | Neurulation, Vesiculation, Neural Crest Cell Migration
Retinoic acid accelerates the specification of enteric neural progenitors from in vitro-derived neural crest