GABAergic interneurons form transient layer-specific circuits in early postnatal neocortex.
GABAergic interneurons form transient layer-specific circuits in early postnatal neocortex.
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GABA能中神经元在早期产后新皮层中形成瞬态特异性电路。
DOI：
10.1038/ncomms10584
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发表时间：
2016-02-04
影响因子：
16.6
通讯作者：
Butt SJ
中科院分区：
文献类型：
--
作者：
Anastasiades PG;Marques-Smith A;Lyngholm D;Lickiss T;Raffiq S;Kätzel D;Miesenböck G;Butt SJ
GABA 能中间神经元在皮质回路中发挥着关键作用，但人们对它们的早期连接知之甚少。在这里，我们使用谷氨酸解笼和一种新颖的光遗传学策略来跟踪发育中的新皮质中间神经元亚型的传入和传出突触连接的变化。我们发现 Nkx2-1 衍生的中间神经元在出现锥体细胞网络之前就具有功能性突触连接。随后的中间神经元电路成熟既依赖于亚型又依赖于层。快速尖峰 (FS) 的谷氨酸输入随着发育而增加，但生长抑素阳性、非 FS 中间神经元的谷氨酸输入不会增加。位于第 (L) 4 层和第 5b 层的两种亚型的中间神经元参与瞬态电路，该电路在体感关键期后消失。其中包括由 L5b 生长抑素阳性中间神经元介导的通路，该通路在产后第一周专门针对 L4。因此，未成熟皮质中间神经元回路的神经支配模式既不是静态的，也不是逐渐加强的，而是遵循与成人大脑不同的瞬态连接的特定层编排。 GABA 能中间神经元是皮质回路的关键组成部分，但其早期连接性尚不清楚。作者在此表明，在出生后早期发育过程中，Nkx2-1 衍生的中间神经元参与层特异性和动态回路，这与成熟新皮质中的回路不同。
GABAergic interneurons play key roles in cortical circuits, yet little is known about their early connectivity. Here we use glutamate uncaging and a novel optogenetic strategy to track changes in the afferent and efferent synaptic connections of developing neocortical interneuron subtypes. We find that Nkx2-1-derived interneurons possess functional synaptic connections before emerging pyramidal cell networks. Subsequent interneuron circuit maturation is both subtype and layer dependent. Glutamatergic input onto fast spiking (FS), but not somatostatin-positive, non-FS interneurons increases over development. Interneurons of both subtype located in layers (L) 4 and 5b engage in transient circuits that disappear after the somatosensory critical period. These include a pathway mediated by L5b somatostatin-positive interneurons that specifically targets L4 during the first postnatal week. The innervation patterns of immature cortical interneuron circuits are thus neither static nor progressively strengthened but follow a layer-specific choreography of transient connections that differ from those of the adult brain. GABAergic interneurons are key components of cortical circuits, yet their early connectivity is unknown. Here the authors show that during early postnatal development, Nkx2-1-derived interneurons engage in layer-specific and dynamic circuits, which are distinct from those in the mature neocortex.