Dynamics of cerebellar Purkinje cell dendrites

描述（由申请人提供）：本提案的长期目标是了解调节小脑神经元回路发育的分子和细胞机制。树突棘是许多投射神经元（如小脑浦肯野细胞）的突触输入位点，是高度动态的结构，其运动受到发育调节。在发育过程中调节脊柱动力学的机制尚不清楚。在这里，我们将使用神经元结构的多光子实时成像在器官型切片和体内结合电子显微镜来研究突触维持的机制。我们的中心假设是神经胶质过程的鞘层对树突脊柱的运动和突触的稳定性起着关键的调节作用。在第一个目标中，我们将使用静态和动态成像方法描述伯格曼胶质细胞过程的发展。在第二个目标中，我们将通过测量神经胶质鞘层减少的遗传模型中的脊柱运动来测试脊柱动力学是如何被神经胶质鞘层调节的。在第三个目标中，我们将确定EphA受体和ephrin配体在胶质-脊柱串音和脊柱动力学调节中的作用。最后，我们将确定突触维持如何与脊柱运动相关，并由胶质过程调节。神经连接的异常发育可能是人类神经发育障碍的原因。此外，最近有研究表明，发育过程中异常的胶质-神经元相互作用可能导致成人精神障碍。因此，了解突触形成和维持过程中胶质-神经元相互作用的细胞和分子机制具有重要的健康意义。

DESCRIPTION (provided by applicant): The long-term goal of this proposal is to understand the molecular and cellular mechanisms that regulate the development of cerebellar neuronal circuits. Dendritic spines, sites of synaptic input on many projection neurons such as the cerebellar Purkinje cell are highly dynamic structures and their motility is developmentally regulated. The mechanisms that regulate spine dynamics over development are not known. Here, we will use multiphoton live imaging of neuronal structures in organotypic slices and in vivo in conjunction with electron microscopy to study the mechanisms of synaptic maintenance. Our central hypothesis is that ensheathment by glial processes critically regulates dendritic spine motility and synaptic stability. In the first aim, we will characterize the development of Bergmann glia processes using static and dynamic imaging approaches. In the second aim, we will test how spine dynamics are regulated by glial ensehathment by measuring spine motility in genetic models with reduced glial ensheathment. In the third aim, we will determine the role of EphA receptors and the ephrin ligands in glia-spine cross talk and regulation of spine dynamics. Finally, we will determine how synaptic maintenance is related to spine motility and is regulated by glial processes. Abnormal development of neuronal connections can be the cause of neurodevelopmental disorders in humans. Moreover, recently it has been demonstrated that abnormal glial-neuronal interactions during development might cause mental disorders in the adult. Therefore, understanding the cellular and molecular mechanisms of glial-neuronal interactions during synapse formation and maintenance has important health significance.