Morgan Josh L, Dhingra Anuradha, Vardi Noga, Wong Rachel O L
Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri 63110, USA.
Nat Neurosci. 2006 Jan;9(1):85-92. doi: 10.1038/nn1615. Epub 2005 Dec 11.
The cellular mechanisms underlying axogenesis and dendritogenesis are not completely understood. The axons and dendrites of retinal bipolar cells, which contact their synaptic partners within specific laminae in the inner and outer retina, provide a good system for exploring these issues. Using transgenic mice expressing enhanced green fluorescent protein (GFP) in a subset of bipolar cells, we determined that axonal and dendritic arbors of these interneurons develop directly from apical and basal processes attached to the outer and inner limiting membranes, respectively. Selective stabilization of processes contributed to stratification of axonal and dendritic arbors within the appropriate synaptic layer. This unusual mode of axogenesis and dendritogenesis from neuroepithelial-like processes may act to preserve neighbor-neighbor relationships in synaptic wiring between the outer and inner retina.
轴突发生和树突发生的细胞机制尚未完全明确。视网膜双极细胞的轴突和树突在视网膜内、外特定层中与它们的突触伙伴接触,为探究这些问题提供了一个良好的系统。利用在一部分双极细胞中表达增强型绿色荧光蛋白(GFP)的转基因小鼠,我们确定这些中间神经元的轴突和树突分支分别直接从附着于外、内界膜的顶端和基部突起发育而来。突起的选择性稳定有助于轴突和树突分支在适当的突触层内分层。这种从神经上皮样突起进行轴突发生和树突发生的不寻常模式可能有助于维持视网膜内、外突触连接中相邻神经元之间的关系。