Shepherd D, Laurent G
Department of Zoology, University of Cambridge, United Kingdom.
J Comp Neurol. 1992 May 15;319(3):438-53. doi: 10.1002/cne.903190309.
We examined the embryonic development of an identified group of thoracic spiking local interneurones in the locust. These interneurones are primary integrators of mechanosensory information from the legs and make inhibitory output connections with motor neurones, nonspiking local interneurones, and intersegmental interneurones. Using intracellular dye injection, we traced the origins of these interneurones and described their morphological development. All of the interneurones in this population are produced by neuroblast NB4-1. The interneurones are produced during the latter stages of the neuroblast lineage and could not be identified before 55% development. Their growth could be divided into three distinct phases: first, a period of initial outgrowth (55-70%) during which the basic skeleton of major neurites is formed; second, a shorter period of rapid growth (70-80%) during which the basic skeleton is elaborated by the addition of many side branches; and third, a period of maturation (80-95%) during which the branches formed during earlier growth appear to be pruned. The possible implications of these results for neural development and synaptogenesis are discussed.
我们研究了蝗虫中一组已确定的胸部刺突局部中间神经元的胚胎发育。这些中间神经元是来自腿部的机械感觉信息的主要整合者，并与运动神经元、非刺突局部中间神经元和节间中间神经元形成抑制性输出连接。通过细胞内染料注射，我们追踪了这些中间神经元的起源并描述了它们的形态发育。这群中间神经元均由神经母细胞NB4-1产生。这些中间神经元在神经母细胞谱系的后期产生，在发育到55%之前无法被识别。它们的生长可分为三个不同阶段：第一，初始生长阶段（55%-70%），在此期间主要神经突的基本骨架形成；第二，较短的快速生长阶段（70%-80%），在此期间通过添加许多侧支对基本骨架进行细化；第三，成熟阶段（80%-95%），在此期间早期生长过程中形成的分支似乎被修剪。我们讨论了这些结果对神经发育和突触形成的可能影响。
