RNA seq profile of adult newborn neurons. RNA seq profile of adult newborn neurons

The integration of adult-born neurons in the existent neural circuitry is known to be activity-dependent. To decipher the underlying mechanisms, we genetically manipulated excitability of adult-born cells (via cell-specific overexpression of either Kv1.2 or Kir2.1 K+ channels). Longitudinal in vivo Ca2+ imaging and transcriptome analyses revealed that endogenous but not sensory-driven activity governs migration, morphogenesis, survival, and functional integration of adult-born juxtaglomerular neurons in the mouse olfactory bulb. The proper development of these cells required fluctuations of cytosolic Ca2+ levels, phosphorylation of CREB, and pCREB-mediated gene expression. Attenuating Ca2+ fluctuations via K+ channel overexpression strongly downregulated genes involved in neuronal migration, differentiation, and morphogenesis and upregulated the apoptosis-related genes, thus locking adult-born cells in the vulnerable and immature state. Together, the data identify signaling pathways connecting the endogenous intermittent neuronal activity/Ca2+ fluctuations as well as proper Kv1.2/Kir2.1 K+ channel function to migration, maturation, and survival of adult-born neurons. Overall design: we used 12 male 3 months-old mice and split them into three groups, namely control NBNs, Kv1.2-overexpressing NBNs, and Kir2.1-overexpressing NBNs. The 4 mice in each group were further divided into two subgroups to have 2 biological replicates in each group. For each sample, NBNs from two mice were pooled together. In total, we analyzed 6 samples.

已知成体新生神经元（adult-born neurons）整合至现有神经环路（neural circuitry）的过程呈活动依赖性（activity-dependent）。为解析其潜在机制，我们通过细胞特异性过表达Kv1.2与Kir2.1型钾离子通道（K+ channels），对成体新生细胞的兴奋性（excitability）进行了遗传操控。纵向活体钙离子成像（longitudinal in vivo Ca2+ imaging）与转录组分析（transcriptome analyses）结果显示，内源性活动（endogenous activity）而非感觉驱动活动（sensory-driven activity），调控着小鼠嗅球（mouse olfactory bulb）中成体新生球旁神经元（adult-born juxtaglomerular neurons，下称NBNs）的迁移、形态发生、存活与功能整合。这类细胞的正常发育依赖于胞质钙离子水平（cytosolic Ca2+ levels）波动、CREB磷酸化（phosphorylation of CREB）以及pCREB介导的基因表达（pCREB-mediated gene expression）。通过钾离子通道过表达减弱钙离子波动，会显著下调参与神经元迁移、分化与形态发生的基因，并上调凋亡相关基因（apoptosis-related genes），从而将成体新生细胞锁定于脆弱且未成熟的状态。综上，本研究数据明确了将内源性间歇性神经元活动（intermittent neuronal activity）/钙离子波动与正常Kv1.2/Kir2.1型钾离子通道功能，关联至成体新生神经元迁移、成熟与存活的信号通路（signaling pathways）。
实验总体设计：我们选用12只3月龄雄性小鼠，将其分为3组，分别为对照组成体新生球旁神经元组、Kv1.2过表达成体新生球旁神经元组以及Kir2.1过表达成体新生球旁神经元组。每组4只小鼠进一步划分为两个亚组，以确保每组设置2个生物学重复（biological replicates）。每个样本均混合2只小鼠的成体新生球旁神经元。最终共完成6个样本的分析。