Neonatal and adult neurogenesis provide two distinct populations of newborn neurons to the mouse olfactory bulb
Neonatal and adult neurogenesis provide two distinct populations of newborn neurons to the mouse olfactory bulb
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DOI：
10.1523/jneurosci.1114-05.2005
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发表时间：
2005-07-20
影响因子：
5.3
通讯作者：
Lledo, PM
中科院分区：
文献类型：
--
作者：
Lemasson, M;Saghatelyan, A;Lledo, PM
在哺乳动物中，嗅球（OB）构成了出生后大脑的两个区域之一，在整个生命中持续神经发生。尽管在成人OB的神经元替代激烈的探索，鲜为人知的是，在出生后早期阶段的运作机制。这个问题是特别相关的，因为大多数局部中间神经元是在新生儿中出生的，当嗅觉控制重要功能时。在这里，我们分析了招聘的新生细胞的颗粒细胞（GC）层（GCL），并发现，出生后的小鼠OB提供了两个时空不同的人口的新生中间神经元。早期出生（出生后第3天（P3）至P7）的GC构成了比后期（P14-P60）产生的GC大三倍的群体，其中一些是在OB本身内局部产生的。在P3-P7产生的新生中间神经元主要针对GCL的外部边缘，而新产生的细胞在老年小鼠中定位更深。此外，尽管接近50%的成年新生儿细胞在到达OB的几周内被消除，但几乎整个早期出生的GC群体都存活到成年。重要的是，早期的嗅觉经验专门修改新生儿中新生儿GC的数量，但成年期产生的神经元数量不变。总之，这些结果表明，出生后早期的神经发生赋予新生儿延髓电路与新生儿GC不同的形态和功能，从成人中产生的。
In mammals, the olfactory bulb ( OB) constitutes one of two regions of the postnatal brain with continuous neurogenesis throughout life. Despite intense explorations of neuronal replacement in the adult OB, little is known about the mechanisms that operate at earlier postnatal stages. This question is particularly pertinent, because the majority of local interneurons are born in the neonate, when olfaction controls vital functions. Here, we analyzed the recruitment of newborn cells to the granule cell (GC) layer (GCL) and found that the postnatal mouse OB is supplied with two spatiotemporally distinct populations of newborn interneurons. Early born [postnatal day 3 (P3) to P7] GCs constitute a threefold larger population compared with those generated later (P14-P60), and some of them are produced locally within the OB itself. Newborn interneurons generated at P3-P7 were predominantly targeted to the external edge of the GCL, whereas newly generated cells were positioned deeper in older mice. Additionally, although similar to 50% of adult newborn cells were eliminated within a few weeks of reaching the OB, almost the entire population of early born GCs survived until adulthood. Importantly, early olfactory experience specifically modifies the number of newborn GCs in neonates but leaves unaltered the amount of neurons generated during adulthood. Together, these results demonstrate that early postnatal neurogenesis endows the neonate bulbar circuit with newborn GCs that differ morphologically and functionally from those produced in the adult.