The distinct temporal origins of olfactory bulb interneuron subtypes
The distinct temporal origins of olfactory bulb interneuron subtypes
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DOI：
10.1523/jneurosci.5625-07.2008
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发表时间：
2008-04-09
影响因子：
5.3
通讯作者：
Fishell, Gord
中科院分区：
文献类型：
--
作者：
Batista-Brito, Renata;Close, Jennie;Fishell, Gord
嗅球（OB）中间神经元是从胚胎发生开始并持续到成年期产生的异质群体。了解这种多样性是如何产生的将有助于深入了解 OB 微电路是如何建立以及成人神经发生的。特定的空间域已被证明有助于特定的中间神经元亚型。然而，OB 中间神经元亚型产生的时间分布尚不清楚。利用 Dlx1/2 前体的诱导遗传命运图谱，我们分析了 7 个 OB 中间神经元亚型的产生，发现每个亚群的产生都有独特的时间特征。在肾小球层内，酪氨酸羟化酶阳性中间神经元的产生在胚胎发生早期达到最大，此后逐渐减少。相比之下，钙结合蛋白中间神经元的产生在胚胎发生后期达到最大，并在出生后下降，而钙结合蛋白（CR）细胞的产生在胚胎发生期间较低，并在出生后增加。外部丛状层内的小白蛋白中间神经元仅在围产期产生，而二尖瓣细胞层中 5T4 阳性颗粒细胞的产生不会随时间发生显着变化。 CR阳性颗粒细胞不是在胚胎早期时间点产生的，但在出生后形成的颗粒细胞中占很大比例。相比之下，布拉内斯细胞在胚胎发生过程中产生的数量最多。我们共同首次对 OB 中间神经元亚型的时间生成进行全面分析，并证明这些群体产生的时间是经过严格精心安排的。
Olfactory bulb (OB) interneurons are a heterogeneous population produced beginning in embryogenesis and continuing through adulthood. Understanding how this diversity arises will provide insight into how OB microcircuitry is established as well as adult neurogenesis. Particular spatial domains have been shown to contribute specific interneuron subtypes. However, the temporal profile by which OB interneuron subtypes are produced is unknown. Using inducible genetic fate mapping of Dlx1/2 precursors, we analyzed the production of seven OB interneuron subtypes and found that the generation of each subpopulation has a unique temporal signature. Within the glomerular layer, the production of tyrosine hydroxylase-positive interneurons is maximal during early embryogenesis and decreases thereafter. In contrast, the generation of calbindin interneurons is maximal during late embryogenesis and declines postnatally, whereas calretinin (CR) cell production is low during embryogenesis and increases postnatally. Parvalbumin interneurons within the external plexiform layer are produced only perinatally, whereas the generation of 5T4-positive granule cells in the mitral cell layer does not change significantly over time. CR-positive granule cells are not produced at early embryonic time points, but constitute a large percentage of the granule cells born after birth. Blanes cells in contrast are produced in greatest number during embryogenesis. Together we provide the first comprehensive analysis of the temporal generation of OB interneuron subtypes and demonstrate that the timing by which these populations are produced is tightly orchestrated.