Mechanisms of Transplanted Cortical Interneuron Survival and Function

项目摘要 皮质中间神经元(CIN)是一种在远离皮质的地方出生时过剩的抑制性细胞。在产前 时间点，CIN前体迁移到小鼠视皮层(V1)，在那里只有一小部分被选择来 活下去。一旦整合到V1回路，表达小白蛋白(PV)或生长抑素(SST)的CIN就会触发 时间受限的可塑性时期，是正常视觉体验所必需的。潜在的分子 细胞活性在选择CIN存活率和CIN介导的可塑性中所起的作用 完全理解。异时移植到受体皮质的PV和/或SST CIN前体 已经被证明遵循类似的生存时间线，并创造了一个受时间限制的可塑性窗口 在遵循“捐赠者”时间线的“宿主”中，揭示移植的CIN以正常的速度发育 并可作为CIN发展的替代物。在这里，我建议使用CIN移植来研究 转录变化和负责选择CIN生存的分子因素(目标2)和 CINS诱导可塑性的能力(目标1)。在本奖项的指导阶段，Aim 1a将研究 移植的PV和SST CIN在宿主中触发可塑性时转录产物的差异表达 视觉皮质。Aim 1b将把这些转录变化与移植受者的PV和SST CIN进行比较 为了测试是否表达了类似的基因，并表征宿主CIN是如何在 通过移植介导的可塑性在分子水平上。Aim 1c将比较基因转录的变化 将PV和SST CIN移植到相应发育年龄以上的内源性PV和SST CIN 幼年关键期，比较移植的CIN开放时的时间基因表达 第二个临界期和内源CINS开启幼虫临界期。在独立期间 在这个奖项的阶段，Aim 2a将跟踪体内移植的CIN在 程序化细胞死亡以确定与生存选择相关的活动的时间线。目标2b将生成 在这一时间线上的基因表达谱，以表征生存与死亡的转录信号。 为了确定是否需要来自目标2b的感兴趣的基因来选择生存，它们的 表达式将在AIM 2c中进行操作。移植的CIN将被RNAi和它们的活性靶向 存活率将被衡量。这项提议将确定新的治疗目标，以形成 功能视觉回路，并开发更易获得的方法，以促进皮质可塑性。

Project Summary Cortical interneurons (cINs) are inhibitory cells that are born in surplus far from the cortex. During prenatal timepoints, cIN precursors migrate into the mouse visual cortex (V1) where only a fraction are selected to survive. Once integrated into the V1 circuit, cINs expressing parvalbumin (PV) or somatostatin (SST) trigger a temporally restricted period of plasticity that is required for normal visual experience. The underlying molecular factors and the role cellular activity plays in the selection of cIN survival and cIN-mediated plasticity are not fully understood. PV and/or SST cIN precursors that are heterochronically transplanted into a recipient cortex have been shown to follow a similar timeline for survival and create a temporally restricted window of plasticity in the “host” that follows the timeline of the “donor”, revealing that transplanted cINs develop at a normal rate and may be used as a proxy for cIN development. Here, I propose to use cIN transplantation to study the transcriptional changes and the molecular factors responsible in selecting cINs for survival (Aim 2) and for the capacity of cINs to induce plasticity (Aim 1). During the mentored phase of this award, Aim 1a will study the differential expression of transcripts from transplanted PV and SST cINs as they trigger plasticity in the host visual cortex. Aim 1b will compare these transcriptional changes to the transplant recipient’s PV and SST cINs to test whether similar genes are expressed and to characterize how host cINs are being affected at the molecular level by transplant-mediated plasticity. Aim 1c will compare the transcriptional changes in transplanted PV and SST cINs to endogenous PV and SST cINs at corresponding developmental ages over the juvenile critical period, to compare the temporal gene expression between transplanted CINs as they open a second critical period and endogenous cINs as they open the juvenile critical period. During the independent phase of this award, Aim 2a will track the excitability of transplanted cINs in vivo during the period of programmed cell death to identify a timeline of activity related to the selection for survival. Aim 2b will generate gene expression profiles over this timeline to characterize transcriptional signatures for survival versus death. To determine whether the genes of interest from Aim 2b are required for the selection of survival, their expression will be manipulated in Aim 2c. Transplanted cINs will be targeted with RNAi and their activity and survival will be measured. This proposal will identify novel therapeutic targets necessary for the formation of functional visual circuits and for developing more accessible ways to promote cortical plasticity.