Biological Sciences, University of Bristol, Woodland Road, Bristol, United Kingdom.
Dev Neurobiol. 2012 Apr;72(4):575-84. doi: 10.1002/dneu.20889.
In young and developing amphibians and fish the spinal cord is functional but remarkably simple compared with the adult. Is the pattern of neurons and their connections common across at least these lower vertebrates? Does this basic pattern extend into the brainstem? Could the development of simple functioning neuronal networks depend on very basic rules of connectivity and act as pioneer networks providing a substrate for the development of more complex and subtle networks. In this review of the functional neuron classes in the Xenopus laevis tadpole spinal cord up to hatching, we will consider progress and difficulties in using anatomy, transcription factor expression, physiology, and activity to define spinal neuron types. Even here it is not straightforward and is rarely possible to bring all the different strands of evidence together. But, we think we have a rather complete picture of the hatchling tadpole spinal neuron types and can define clear roles for most of them in behavior. Our present knowledge about the hatchling Xenopus spinal cord should set up many of the problems to be unraveled in the future by more developmentally oriented research.
在年轻和正在发育的两栖动物和鱼类中，与成年动物相比，脊髓具有功能但非常简单。神经元及其连接的模式是否在至少这些低等脊椎动物中普遍存在？这种基本模式是否延伸到脑干？简单功能神经元网络的发育是否可能取决于非常基本的连接规则，并作为先驱网络为更复杂和微妙的网络的发展提供基础。在这篇对非洲爪蟾蝌蚪脊髓中功能神经元类别的综述中，我们将考虑使用解剖学、转录因子表达、生理学和活动来定义脊髓神经元类型的进展和困难。即使在这里，也不容易将所有不同的证据线索结合起来。但是，我们认为我们对孵化期蝌蚪脊髓神经元类型有了相当完整的了解，可以为它们中的大多数在行为中的作用定义明确的角色。我们目前对孵化期非洲爪蟾脊髓的了解应该为未来更具发展导向的研究要解决的许多问题奠定基础。
