PDF(Pubmed)
Abstract：
Olfactory sensory neurons (OSNs) are one of a few neuron types that are generated continuously throughout life in mammals. The persistence of olfactory sensory neurogenesis beyond early development has long been thought to function simply to replace neurons that are lost or damaged through exposure to environmental insults. The possibility that olfactory sensory neurogenesis may also serve an adaptive function has received relatively little consideration, largely due to the assumption that the generation of new OSNs is stochastic with respect to OSN subtype, as defined by the single odorant receptor gene that each neural precursor stochastically chooses for expression out of hundreds of possibilities. Accordingly, the relative birthrates of different OSN subtypes are predicted to be constant and impervious to olfactory experience. This assumption has been called into question, however, by evidence that the birthrates of specific OSN subtypes can be selectively altered by manipulating olfactory experience through olfactory deprivation, enrichment, and conditioning paradigms. Moreover, studies of recovery of the OSN population following injury provide further evidence that olfactory sensory neurogenesis may not be strictly stochastic with respect to subtype. Here we review this evidence and consider mechanistic and functional implications of the prospect that specific olfactory experiences can regulate olfactory sensory neurogenesis rates in a subtype-selective manner.
摘要：
嗅觉感觉神经元（OSN）是哺乳动物一生中连续产生的几种神经元类型之一。长期以来，人们一直认为嗅觉感觉神经发生的持久性超出了早期发育的范围，其功能只是为了替换因暴露于环境损害而丢失或受损的神经元。嗅觉感觉神经发生也可能发挥适应性功能的可能性已经得到了相对较少的考虑，很大程度上是由于假设新OSN的生成相对于OSN亚型是随机的，由单个气味受体基因定义，每个神经前体在数百种可能性中随机选择表达。因此，预测不同OSN亚型的相对出生率是恒定的，并且不受嗅觉体验的影响。这个假设受到质疑，然而,有证据表明，特定OSN亚型的出生率可以通过嗅觉剥夺来操纵嗅觉体验而选择性地改变，富集,和条件范式。此外，对损伤后OSN人群恢复的研究提供了进一步的证据，表明嗅觉感觉神经发生在亚型方面可能不是严格随机的。在这里，我们回顾了这些证据，并考虑了特定嗅觉体验可以以亚型选择性方式调节嗅觉感觉神经发生率的前景的机制和功能含义。
