Induction of Neurogenesis in Neocortex for Brain Repair

描述(由申请人提供)：建议的长期目标 实验是修复受损的新皮质回路。我们之前的大部分时间 工作的重点是通过移植未成熟的神经元和神经元进行修复 先驱物。然而，最近，我们已经操纵了内源性前体 成年小鼠神经发生和解剖环路的原位观察 在通常不会发生的新大脑皮层重新形成，这是 是没有移植的。这项工作旨在达到修复的最终目标 通过在原位操纵内源性神经前体。这可能会导致 皮质退行性、发育性或获得性疾病的治疗 它的输出电路(如脊髓)。在新大脑皮层， 这种未来的治疗可能关键取决于内源性前体细胞， 或干细胞，可以精确地诱导形成新的神经元；迁移以纠正 定位；适当区分和整合；重塑精准 远距离投影和复杂的功能连接。 神经母细胞和神经前体细胞对基因表达改变的特异性反应 大脑皮层区域的局部信号分子正在经历同步 生物物理学诱导投射神经元的凋亡。他们有选择地迁移 进入这些区域，分化成投射神经元，接受突触 输入，并对长途电路进行改造。 尽管我们在确定在哪些条件下 皮质神经发生和皮质回路的部分修复是可能的 对于成年人来说，还有很多问题有待调查。这些问题形成了 拟议研究的基础是：1)我们能否大幅增加 通过调控新皮质神经元的增殖/分化 内源性前体和/或新生神经元的存活？2)新生神经元 精确地分化成新的功能投射-神经元，接收 传入突触，并成为功能完整的？3)什么是 诱导神经发生的分子机制和特异性 成体新皮质内源性前体的分化？我们的三个 具体目标将直接测试和调查这些问题。建议 实验将：目的1)确定选定的候选生长的效果 增加大脑皮层神经生长期诱导量的因素 成年小鼠；目的2)研究新生神经元分化的精确度 通过对神经递质和受体补体及突触的分析 整合，使用共聚焦和免疫细胞化学；以及目标3)研究 通过基因芯片分析这种诱导神经发生的分子机制 差异基因表达，候选基因的确认，以及体外 功能测定。总之，这些实验将研究分子 成年小鼠新皮质诱导神经发生的机制 有可能大幅增加神经发生的数量；以及 内源性前体细胞来源的新生大脑皮层神经元 修复大脑皮层电路。

DESCRIPTION (provided by applicant): The long-term goal of the proposed experiments is the repair of damaged neocortical circuitry. Much of our prior work has focused on repair by transplantation of immature neurons and neural precursors. Recently, however, we have manipulated endogenous precursors in situ in the adult mouse to undergo neurogenesis and anatomic circuit re-formation de novo in the neocortex, where it does not normally occur, This was without transplantation. This work aims toward the ultimate goal of repair by manipulation of endogenous neural precursors in situ. This could lead to therapies for degenerative, developmental, or acquired diseases of cortex and its output circuitry (e.g. spinal cord). In neocortex, the effectiveness of such future therapies could depend critically on whether endogenous precursors, or stem cells, can be precisely induced to form new neurons; migrate to correct locations; differentiate and integrate appropriately; and re-form precise long-distance projections and complex functional connections. Neuroblasts and neural precursors respond specifically to altered expression of local signal molecules in regions of cortex undergoing synchronous biophysically-induced apoptosis of projection neurons. They selectively migrate into such regions, differentiate into projection neurons, receive synaptic input, and re-form long-distance circuitry. Though we have made considerable progress in identifying conditions under which cortical neurogenesis and partial repair of cortical circuitry is possible in the adult, many questions still remain to be investigated. These questions form the basis of the proposed research: 1) Can we substantially increase the number of new cortical neurons by manipulating proliferation/differentiation of endogenous precursors &/or survival of newborn neurons? 2) Can newborn neurons differentiate precisely into new functional projection-neurons, receive afferent synapses, and become functionally integrated? 3) What are the molecular mechanisms responsible for inducing neurogenesis and specific differentiation by endogenous precursors in the adult neocortex? Our three specific aims will test and investigate these questions directly. Proposed experiments will: Aim 1) determine the effects of select candidate growth factors toward increasing the amount of induced neurogenesis in neocortex of adult mice; Aim 2) investigate the precision of newborn neuron differentiation by analysis of neurotransmitter and receptor complement and synaptic integration, using confocal and immunocytochemistry; and Aim 3) investigate the molecular mechanisms of this induced neurogenesis via microarray analysis of differential gene expression, confirmation of candidates, and in vitro functional assay. Together, these experiments will investigate the molecular mechanisms underlying induced neurogenesis in the adult murine neocortex; the potential for substantially increasing the amount of neurogenesis; and the ability of newborn cortical neurons derived from endogenous precursors to repair cortical circuitry.