Research on the intermediate progenitors of GABAergic neurons found in the subventricular zone of the mouse neocortex

在胚胎新皮层中，神经元前体在心室区（VZ）产生，并在皮层板中积累。最近，胚胎新皮层的室下区（SVZ）被认为是主要兴奋性神经元和gaba能抑制神经元的另一个神经发生位点。为了进一步了解GABAergic神经元在SVZ的神经发生，我们采用免疫组织化学、免疫细胞化学、单细胞RT-PCR和单细胞阵列分析等方法研究了小鼠新皮层GABAergic神经元中间祖细胞（IPGNs）的特征。通过表达一些神经元和细胞周期标记物来鉴定IPGNs。此外，我们通过转基因小鼠的Cre-loxP命运定位和Cre-loxP报告质粒对部分端脑VZ的转导研究了新皮质IPGNs的起源，发现它们位于内侧和外侧神经节隆起。因此，它们必须在端脑内切向迁移才能到达新皮层。通过简单逆转录病毒转导的细胞系分析表明，新皮质IPGNs自我更新并在嗅球中产生少量的新皮质gaba能神经元和大量的颗粒细胞和肾小球周围细胞。ipgn维持在新皮层中，并可能作为成人神经发生的祖细胞。

In the embryonic neocortex, neuronal precursors are generated in the ventricular zone(VZ) and accumulate in the cortical plate. Recently, the subventricular zone(SVZ) of the embryonic neocortex was recognized as an additional neurogenic site for both principal excitatory neurons and GABAergic inhibitory neurons. To gain insight into the neurogenesis of GABAergic neurons in the SVZ, we investigated the characteristics of intermediate progenitors of GABAergic neurons(IPGNs) in mouse neocortex by immunohistochemistry, immunocytochemistry, single-cell RT-PCR, and single-cell array analysis. IPGNs were identified by their expression of some neuronal and cell cycle markers. Moreover, we investigated the origins of the neocortical IPGNs by Cre-loxP fate mapping in transgenic mice and the transduction of part of the telencephalic VZ by Cre-reporter plasmids, and found them in the medial and lateral ganglionic eminence. Therefore they must migrate tangentially within the telencephalon to reach the neocortex. Cell-lineage analysis by simple-retrovirus transduction revealed that the neocortical IPGNs self-renew and give rise to a small number of neocortical GABAergic neurons and a large number of granule and periglomerular cells in the olfactory bulb. IPGNs are maintained in the neocortex and may act as progenitors for adult neurogenesis.