Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA.
Neuron. 2013 Sep 4;79(5):970-86. doi: 10.1016/j.neuron.2013.06.043.
A dynamic interplay between intrinsic regional molecular cues and extrinsic factors from the thalamus shape multiple features of early cortical development. It remains uncertain and controversial, however, whether the initial formation of cortical columns depends on neuronal activity, and there is little evidence that cortical lamination or neuronal differentiation is influenced by extrinsic activity. We examined the role of thalamic-derived factors in cortical development by selectively eliminating glutamatergic synaptic transmission from thalamocortical neurons in mice and found that eliminating thalamocortical neurotransmission prevented the formation of "barrel" columns in somatosensory cortex. Interestingly, based on cytoarchitectonic criteria and genetic markers, blocking thalamocortical neurotransmission also perturbed the development of superficial cortical lamina and the morphologic development of neurons. These experiments demonstrate that barrels and aspects of the layer-dependent pattern of cortical cytoarchitecture, gene expression, and neuronal differentiation depend on thalamocortical neurotransmission, extending the apparent influence of extrinsic, presumably activity-dependent factors, on cortical development.
内在区域分子线索与来自丘脑的外在因素之间的动态相互作用塑造了早期皮层发育的多个特征。然而，皮层柱的最初形成是否依赖于神经元活动仍然不确定且存在争议，而且几乎没有证据表明皮层分层或神经元分化受到外在活动的影响。我们通过选择性地消除小鼠丘脑皮质神经元中的谷氨酸能突触传递来研究丘脑衍生因子在皮层发育中的作用，发现消除丘脑皮质神经传递可防止体感皮层中“桶状”柱的形成。有趣的是，基于细胞构筑学标准和遗传标记，阻断丘脑皮质神经传递也会干扰浅层皮层的发育和神经元的形态发育。这些实验表明，桶状结构和皮层细胞构筑、基因表达和神经元分化的依赖于层的模式的某些方面取决于丘脑皮质神经传递，这扩展了外在的、可能依赖于活动的因素对皮层发育的明显影响。
