Torigoe Makio, Yamauchi Kenta, Kimura Toshiya, Uemura Yo, Murakami Fujio
Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 560-8531, Japan.
Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 560-8531, Japan
J Neurosci. 2016 Feb 10;36(6):2044-56. doi: 10.1523/JNEUROSCI.3550-15.2016.
Neocortical interneurons show tremendous diversity in terms of their neurochemical marker expressions, morphology, electrophysiological properties, and laminar fate. Allocation of interneurons to their appropriate regions and layers in the neocortex is thought to play important roles for the emergence of higher functions of the neocortex. Neocortical interneurons mainly originate from the medial ganglionic eminence (MGE) and the caudal ganglionic eminence (CGE). The diversity and the laminar fate of MGE-derived interneurons depend on the location of their birth and birthdate, respectively. However, this relationship does not hold for CGE-derived interneurons. Here, using the method of in utero electroporation, which causes arbitrary occurrence of labeled progenitor domains, we tracked all descendants of the lateral ganglionic eminence (LGE)/CGE progenitors in mice. We provide evidence that neocortical interneurons with distinct laminar fate originate from distinct progenitor domains within the LGE/CGE. We find layer I interneurons are predominantly labeled in a set of animals, whereas other upper layer neurons are predominantly labeled in another set. We also find distinct subcortical structures labeled between the two sets. Further, interneurons labeled in layer I show distinct neurochemical properties from those in other layers. Together, these results suggest that the laminar fate of LGE/CGE-derived interneurons depends on their spatial origin.
Diverse types of neocortical interneurons have distinct laminar fate, neurochemical marker expression, morphology, and electrophysiological properties. Although the specifications and laminar fate of medial ganglionic eminence-derived neocortical interneurons depend on their location of embryonic origin and birthdate, no similar causality of lateral/caudal ganglionic eminence (LGE/CGE)-derived neocortical interneurons is known. Here, we performed in utero electroporation on mouse LGE/CGE and found two groups of animals, one with preferential labeling of layer I and the other with preferential labeling of other layers. Interneurons labeled in these two groups show distinct neurochemical properties and morphologies and are associated with labeling of distinct subcortical structures. These findings suggest that the laminar fate of LGE/CGE-derived neocortical interneurons depends on their spatial origin.
新皮质中间神经元在神经化学标志物表达、形态、电生理特性和分层命运方面表现出巨大的多样性。中间神经元在新皮质中分配到适当的区域和层被认为对新皮质高级功能的出现起着重要作用。新皮质中间神经元主要起源于内侧神经节隆起（MGE）和尾侧神经节隆起（CGE）。源自MGE的中间神经元的多样性和分层命运分别取决于它们的出生位置和出生日期。然而，这种关系不适用于源自CGE的中间神经元。在这里，我们使用子宫内电穿孔方法，该方法可导致标记祖细胞区域的任意出现，我们追踪了小鼠外侧神经节隆起（LGE）/CGE祖细胞的所有后代。我们提供证据表明，具有不同分层命运的新皮质中间神经元起源于LGE/CGE内不同的祖细胞区域。我们发现一组动物中主要标记了第I层中间神经元，而在另一组动物中主要标记了其他上层神经元。我们还发现在这两组之间标记了不同的皮质下结构。此外，在第I层标记的中间神经元与其他层的中间神经元表现出不同的神经化学特性。总之，这些结果表明源自LGE/CGE的中间神经元的分层命运取决于它们的空间起源。
多种类型的新皮质中间神经元具有不同的分层命运、神经化学标志物表达、形态和电生理特性。尽管源自内侧神经节隆起的新皮质中间神经元的特化和分层命运取决于它们的胚胎起源位置和出生日期，但对于源自外侧/尾侧神经节隆起（LGE/CGE）的新皮质中间神经元，尚无类似的因果关系。在这里，我们对小鼠LGE/CGE进行了子宫内电穿孔，发现了两组动物，一组优先标记第I层，另一组优先标记其他层。在这两组中标记的中间神经元表现出不同的神经化学特性和形态，并与不同皮质下结构的标记相关。这些发现表明源自LGE/CGE的新皮质中间神经元的分层命运取决于它们的空间起源。
