Weill Cornell Medical College, 1300 York Avenue New York, NY 10065, USA.
Neuron. 2010 Feb 11;65(3):328-40. doi: 10.1016/j.neuron.2010.01.004.
Interneurons in the cerebral cortex regulate cortical functions through the actions of distinct subgroups that express parvalbumin, somatostatin, or calretinin. The genesis of the first two subgroups requires the expression of NKX2.1, which is maintained by SHH signaling during neurogenesis. In this paper, we report that mosaic elimination in the medial ganglionic eminence (MGE) of Smo, a key effector of SHH signaling, reveals that MGE progenitors retain a remarkable degree of plasticity during the neurogenic period. SHH signaling prevents the upregulation of GSX2 and conversion of some MGE progenitors to a caudal ganglionic eminence-like, bipolar calretinin-expressing cell fate that is promoted by GSX2. In addition, a higher level of SHH signaling promotes the generation of the somatostatin-expressing interneuron at the expense of parvalbumin-expressing subgroup. These results indicate that cortical interneuron diversity, a major determinant of cortical function, is critically influenced by differential levels of SHH signaling within the ventral telencephalon.
大脑皮层中的中间神经元通过表达 parvalbumin、somatostatin 或 calretinin 的不同亚群的作用来调节皮层功能。前两个亚群的产生需要 NKX2.1 的表达，而 NKX2.1 的表达在神经发生过程中由 SHH 信号维持。在本文中，我们报告说，在 SHH 信号的关键效应因子 Smo 中对内侧神经节隆起（MGE）进行镶嵌性消除表明，MGE 祖细胞在神经发生期间保持着显著的可塑性。SHH 信号阻止 GSX2 的上调，并将一些 MGE 祖细胞转化为更类似于尾状神经节的、双极 calretinin 表达的细胞命运，而 GSX2 则促进这种转化。此外，更高水平的 SHH 信号促进了表达 somatostatin 的中间神经元的产生，而牺牲了表达 parvalbumin 的亚群。这些结果表明，皮层中间神经元的多样性是皮层功能的主要决定因素，而腹侧端脑中不同水平的 SHH 信号对其具有关键性影响。
