Malvaut Sarah, Saghatelyan Armen
Cellular Neurobiology Unit, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec City, QC, Canada G1J 2G3.
Cellular Neurobiology Unit, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Québec City, QC, Canada G1J 2G3; Department of Psychiatry and Neuroscience, Université Laval, Québec City, QC, Canada G1K 7P4.
Neural Plast. 2016;2016:1614329. doi: 10.1155/2016/1614329. Epub 2015 Dec 29.
The adult mammalian brain is remarkably plastic and constantly undergoes structurofunctional modifications in response to environmental stimuli. In many regions plasticity is manifested by modifications in the efficacy of existing synaptic connections or synapse formation and elimination. In a few regions, however, plasticity is brought by the addition of new neurons that integrate into established neuronal networks. This type of neuronal plasticity is particularly prominent in the olfactory bulb (OB) where thousands of neuronal progenitors are produced on a daily basis in the subventricular zone (SVZ) and migrate along the rostral migratory stream (RMS) towards the OB. In the OB, these neuronal precursors differentiate into local interneurons, mature, and functionally integrate into the bulbar network by establishing output synapses with principal neurons. Despite continuous progress, it is still not well understood how normal functioning of the OB is preserved in the constantly remodelling bulbar network and what role adult-born neurons play in odor behaviour. In this review we will discuss different levels of morphofunctional plasticity effected by adult-born neurons and their functional role in the adult OB and also highlight the possibility that different subpopulations of adult-born cells may fulfill distinct functions in the OB neuronal network and odor behaviour.
成年哺乳动物的大脑具有显著的可塑性，会不断根据环境刺激进行结构和功能上的改变。在许多区域，可塑性表现为现有突触连接效率的改变，或突触的形成与消除。然而，在少数区域，可塑性是由新神经元的加入带来的，这些新神经元会融入已有的神经网络。这种神经元可塑性在嗅球（OB）中尤为突出，在脑室下区（SVZ）每天会产生数千个神经元祖细胞，它们沿着吻侧迁移流（RMS）向嗅球迁移。在嗅球中，这些神经元前体细胞分化为局部中间神经元，成熟后通过与主神经元建立输出突触，在功能上融入嗅球网络。尽管取得了持续进展，但在不断重塑的嗅球网络中，嗅球的正常功能是如何得以维持的，以及成年新生神经元在气味行为中发挥何种作用，目前仍不清楚。在这篇综述中，我们将讨论成年新生神经元所影响的不同层面的形态功能可塑性及其在成年嗅球中的功能作用，还将强调成年新生细胞的不同亚群可能在嗅球神经元网络和气味行为中发挥不同功能的可能性。
