Cuntz Hermann, Forstner Friedrich, Haag Juergen, Borst Alexander
Wolfson Institute for Biomedical Research and Department of Physiology, University College London, London, UK.
PLoS Comput Biol. 2008 Dec;4(12):e1000251. doi: 10.1371/journal.pcbi.1000251. Epub 2008 Dec 26.
Dendrite morphology, a neuron's anatomical fingerprint, is a neuroscientist's asset in unveiling organizational principles in the brain. However, the genetic program encoding the morphological identity of a single dendrite remains a mystery. In order to obtain a formal understanding of dendritic branching, we studied distributions of morphological parameters in a group of four individually identifiable neurons of the fly visual system. We found that parameters relating to the branching topology were similar throughout all cells. Only parameters relating to the area covered by the dendrite were cell type specific. With these areas, artificial dendrites were grown based on optimization principles minimizing the amount of wiring and maximizing synaptic democracy. Although the same branching rule was used for all cells, this yielded dendritic structures virtually indistinguishable from their real counterparts. From these principles we derived a fully-automated model-based neuron reconstruction procedure validating the artificial branching rule. In conclusion, we suggest that the genetic program implementing neuronal branching could be constant in all cells whereas the one responsible for the dendrite spanning field should be cell specific.
树突形态作为神经元的解剖学特征，是神经科学家揭示大脑组织原理的宝贵资源。然而，编码单个树突形态特征的基因程序仍是个谜。为了正式理解树突分支，我们研究了果蝇视觉系统中一组四个可单独识别的神经元的形态参数分布。我们发现，与分支拓扑相关的参数在所有细胞中都相似。只有与树突覆盖面积相关的参数是细胞类型特异性的。利用这些面积，基于优化原则生成人工树突，以尽量减少布线量并最大化突触民主性。尽管所有细胞都使用相同的分支规则，但生成的树突结构与真实结构几乎无法区分。基于这些原则，我们推导出了一个基于模型的全自动神经元重建程序，验证了人工分支规则。总之，我们认为实施神经元分支的基因程序在所有细胞中可能是恒定的，而负责树突跨域的程序应该是细胞特异性的。
