Enriched odor exposure increases the number of newborn neurons in the adult olfactory bulb and improves odor memory
Enriched odor exposure increases the number of newborn neurons in the adult olfactory bulb and improves odor memory
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DOI：
10.1523/jneurosci.22-07-02679.2002
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发表时间：
2002-04-01
影响因子：
5.3
通讯作者：
Lledo, PM
中科院分区：
文献类型：
--
作者：
Rochefort, C;Gheusi, G;Lledo, PM
在哺乳动物前脑中，大多数神经元起源于侧脑室衬里的脑室区中的增殖细胞，包括脑室下区（SVZ）的离散区域。在这个区域，神经发生持续到成年。在SVZ中产生的大多数细胞是神经元前体，其后代在到达主嗅球（MOB）之前沿着称为吻侧迁移流的途径沿着吻侧迁移，在主嗅球（MOB）中它们分化成局部中间神经元。因此，嗅觉系统提供了一个有吸引力的模型来研究神经元的产生和存活，涉及遗传和表观遗传影响之间的相互作用的过程。本研究旨在探讨暴露于气味丰富的环境是否会影响成年小鼠的神经发生和学习。动物居住在一个标准的或气味丰富的环境中40天，腹膜内注射溴脱氧尿苷（BrdU），以检测祖细胞之间的增殖，并遵循他们的生存在MOB。单次注射BrdU后4小时，BrdU标记神经元的数量没有改变。相反，在富集环境中饲养的动物中，注射BrdU 3周后存活的祖细胞数量显著增加。这种效应是特定的，因为丰富的气味暴露不影响海马神经发生。最后，我们发现，在气味丰富的笼子里饲养的成年小鼠表现出改善的嗅觉记忆，而空间学习表现没有变化。通过维持颗粒细胞的组成性周转受到环境线索的调制，持续的延髓神经发生可能与改善嗅觉记忆。
In the mammalian forebrain, most neurons originate from proliferating cells in the ventricular zone lining the lateral ventricles, including a discrete area of the subventricular zone (SVZ). In this region, neurogenesis continues into adulthood. Most of the cells generated in the SVZ are neuronal precursors with progeny that migrate rostrally along a pathway known as the rostral migratory stream before they reach the main olfactory bulb (MOB) where they differentiate into local interneurons. The olfactory system thus provides an attractive model to investigate neuronal production and survival, processes involving interplay between genetic and epigenetic influences. The present study was conducted to investigate whether exposure to an odor-enriched environment affects neurogenesis and learning in adult mice. Animals housed in either a standard or an odor-enriched environment for 40 d were injected intraperitoneally with bromodeoxyuridine (BrdU) to detect proliferation among progenitor cells and to follow their survival in the MOB. The number of BrdU-labeled neurons was not altered 4 hr after a single BrdU injection. In contrast, the number of surviving progenitors 3 weeks after BrdU injection was markedly increased in animals housed in an enriched environment. This effect was specific because enriched odor exposure did not influence hippocampal neurogenesis. Finally, we showed that adult mice housed in odor-enriched cages display improved olfactory memory without a change in spatial learning performance. By maintaining a constitutive turnover of granule cells subjected to modulation by environmental cues, ongoing bulbar neurogenesis could be associated with improved olfactory memory.