Developmental Origin of Patchy Axonal Connectivity in the Neocortex: A Computational Model
Developmental Origin of Patchy Axonal Connectivity in the Neocortex: A Computational Model
复制标题
DOI：
10.1093/cercor/bhs327
复制
发表时间：
2014-02-01
期刊：
影响因子：
3.7
通讯作者：
Douglas, Rodney J.
中科院分区：
文献类型：
--
作者：
Bauer, Roman;Zubler, Frederic;Douglas, Rodney J.
将神经示踪剂注射到许多哺乳动物的新皮质区域，发现了一个常见的簇状轴突投射的斑块图案。我们在模拟中研究了神经元发育的数学模型，以研究这种斑块连接是如何在新皮质的II/III层出现的。在我们的模型中，这一层的单个神经元表达了GierMeinhardt反应扩散系统的激活抑制成分。由此产生的稳态反应扩散模式在整个神经元群体中近似为六角形。在延伸轴突的顶端，生长锥体使用斑块内神经元分泌的各种形态因子作为指导线索来指导它们的生长并激活轴突树枝，因此在整个II/III层产生了斑块状的树枝分布。我们发现，调整单个参数可以产生平均斑块直径和斑块间距之间有趣的线性关系，这种关系已经在许多皮质区域和物种上实验观察到。我们的结论是，由发育中的新皮质神经元表达的一个简单的GiererMeinhardt系统足以解释实验观察到的簇状连接模式。
Injections of neural tracers into many mammalian neocortical areas reveal a common patchy motif of clustered axonal projections. We studied in simulation a mathematical model for neuronal development in order to investigate how this patchy connectivity could arise in layer II/III of the neocortex. In our model, individual neurons of this layer expressed the activatorinhibitor components of a GiererMeinhardt reactiondiffusion system. The resultant steady-state reactiondiffusion pattern across the neuronal population was approximately hexagonal. Growth cones at the tips of extending axons used the various morphogens secreted by intrapatch neurons as guidance cues to direct their growth and invoke axonal arborization, so yielding a patchy distribution of arborization across the entire layer II/III. We found that adjustment of a single parameter yields the intriguing linear relationship between average patch diameter and interpatch spacing that has been observed experimentally over many cortical areas and species. We conclude that a simple GiererMeinhardt system expressed by the neurons of the developing neocortex is sufficient to explain the patterns of clustered connectivity observed experimentally.