Wallace Jenelle L, Wienisch Martin, Murthy Venkatesh N
Molecules, Cells, and Organisms training program, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Neuron. 2017 Nov 15;96(4):883-896.e7. doi: 10.1016/j.neuron.2017.09.039. Epub 2017 Oct 19.
New neurons appear only in a few regions of the adult mammalian brain and become integrated into existing circuits. Little is known about the functional development of individual neurons in vivo. We examined the functional life history of adult-born granule cells (abGCs) in the olfactory bulb using multiphoton imaging in awake and anesthetized mice. We found that abGCs can become responsive to odorants soon after they arrive in the olfactory bulb. Tracking identified abGCs over weeks revealed that the robust and broadly tuned responses of most newly arrived abGCs gradually become more selective over a period of ∼3 weeks, but a small fraction achieves broader tuning with maturation. Enriching the olfactory environment of mice prolonged the period over which abGCs were strongly and broadly responsive to odorants. Our data offer direct support for rapid integration of adult-born neurons into existing circuits, followed by experience-dependent refinement of their functional connectivity.
新神经元仅出现在成年哺乳动物大脑的少数区域，并融入现有的神经回路中。关于体内单个神经元的功能发育，人们了解甚少。我们利用多光子成像技术，在清醒和麻醉的小鼠中研究了嗅球中成年新生颗粒细胞（abGCs）的功能生命历程。我们发现，abGCs到达嗅球后不久就能对气味产生反应。对已识别的abGCs进行数周的追踪显示，大多数新到达的abGCs最初强烈且广泛的调谐反应在约3周的时间内逐渐变得更具选择性，但一小部分细胞随着成熟会实现更广泛的调谐。丰富小鼠的嗅觉环境延长了abGCs对气味产生强烈且广泛反应的时间。我们的数据为成年新生神经元快速融入现有神经回路，随后通过经验依赖对其功能连接进行优化提供了直接支持。
