Correlated light and ultrastructural imaging of learning-related synaptic plasticity

学习涉及大脑神经元之间复杂连接方案的重组。 这种重新连接的关键是新突触连接的形成，因此研究控制神经元的规则， 突触形成仍然是神经科学的中心焦点。在过去的十年里， 很明显，突触遵循特定的空间组织原则，这样功能相似的突触往往 在树突上“聚集”。这种空间模式可能提供了计算优势，允许神经元 有效地构建其输入库的表示。然而，目前尚不清楚是否以及如何新的 在学习过程中形成的突触有助于突触的这种功能聚集。我们建议使用 结合尖端成像技术，研究新的脊柱形成及其潜力 聚类模式-通过学习，将局部突触活动概况的详细描述与 对周围组织的细胞和亚细胞解剖结构的深入研究。我们会在第一时间 在学习运动技能超过2周的小鼠体内应用树突棘的纵向功能成像， 随后对体内成像的体积进行3D电子显微镜检查，以进行高分辨率重建， 相关结构，包括未标记用于体内成像的那些。这种方法将揭示两者如何 神经元树突的结构和功能环境与新突触的形成有关。通过 专注于新的突触，其活动与同一区域上的其他邻近突触变得一致， 树突，我们将提供一个全面的描述如何在学习过程中的棘有助于功能性 突触群集此外，通过重建附近的细胞结构，我们将提供迄今为止， 无法获得的细节，例如这些功能相关的突触是否共享相同的轴突输入。最后， 通过使用一个很好的学习模型，这项工作也将允许一个定量的描述如何新的 脊椎和它们形成的集群与习得行为的特定特征有关。实验 本研究所建立的一个范式将广泛应用于神经回路的研究 其他类型的学习和行为的基础。影响神经元的神经系统疾病的患病率 连通性突出了这一追求的重要性。

Learning involves the reorganization of the complex connectivity schemes between neurons in the brain. Critical to this re-wiring is the formation of new synaptic connections, and thus the study of the rules governing synapse formation remains a central focus of neuroscience. Over the past decade, it has become increasingly clear that synapses follow specific spatial organizational principles, such that functionally similar synapses tend to “cluster” on dendrites. This spatial patterning likely affords computational advantages that allow neurons to efficiently construct representations of their input repertoire. However, it is unknown whether and how new synapses that form during learning contribute to such functional clustering of synapses. We propose to use a combination of cutting-edge imaging techniques to investigate new spine formation - and their potential clustering patterns - over learning, integrating a detailed description of the local synaptic activity profiles with a deep interrogation of the cellular and subcellular anatomy of the surrounding tissue. We will do this by first applying longitudinal functional imaging of dendritic spines in vivo in mice learning a motor skill over 2 weeks, followed by 3D electron microscopy of the volume imaged in vivo for a high-resolution reconstruction of relevant structures, including those that are not labeled for in vivo imaging. This approach will reveal how both the structural and functional environment of neuronal dendrites relates to the formation of new synapses. By focusing on new synapses whose activity becomes coherent with other nearby synapses on the same dendrite, we will provide a thorough description of how spinogenesis during learning contributes to functional synaptic clustering. Furthermore, by reconstructing the nearby cellular structures, we will provide heretofore inaccessible details, such as whether such functionally related synapses share the same axonal inputs. Finally, by using a well characterized model of learning, this work will also allow a quantitative description of how new spines and the clusters that they form relate to specific features of a learned behavior. The experimental paradigm established in the proposed project will be widely applicable to the studies of neural circuits underlying other types of learning and behavior. The prevalence of neurological diseases affecting neuronal connectivity highlights the importance this pursuit.