Cold Spring Harbor Laboratory, Cold Spring Harbor, New York.
Ann N Y Acad Sci. 2013 Dec;1305:44-60. doi: 10.1111/nyas.12324.
Neural development leads to the establishment of precise connectivity in the nervous system. By contrasting the information capacities of cortical connectivity and the genome, we suggest that simplifying rules are necessary in order to create cortical connections from the limited set of instructions contained in the genome. One of these rules may be employed by the visual system, where connections are formed on the basis of the interplay of molecular gradients and activity-dependent synaptic plasticity. We show how a simple model that accounts for such interplay can create both neural topographic maps and more complex patterns of ocular dominance, that is, the segregated binary mixture of projections from two eyes converging in the same visual area. With regard to the ocular dominance patterns, we show that pattern orientation may be instructed by the direction of the gradients of molecular labels. We also show that the periodicity of ocular dominance patterns may result from the interplay of the effects of molecular gradients and correlated neural activity. Overall, we propose that simple mechanisms can account for the formation of apparently complex features of neuronal connections.
神经发育导致神经系统中精确连接的建立。通过对比皮质连接和基因组的信息容量，我们提出为了从基因组中包含的有限指令集中创建皮质连接，简化规则是必要的。这些规则之一可能被视觉系统采用，其中连接是基于分子梯度和活动依赖性突触可塑性的相互作用形成的。我们展示了一个简单的模型如何在解释这种相互作用的基础上，既能创建神经拓扑图，又能创建更复杂的眼优势模式，即来自两只眼睛的投射在同一视觉区域汇聚的分离二进制混合物。关于眼优势模式，我们表明模式方向可以由分子标记梯度的方向来指示。我们还表明，眼优势模式的周期性可能是由分子梯度和相关神经活动的相互作用的影响产生的。总的来说，我们提出简单的机制可以解释神经元连接的明显复杂特征的形成。
