PDF(Pubmed)
Abstract：
Oligodendrocyte-lineage cells are central nervous system (CNS) glia that perform multiple functions including the selective myelination of some but not all axons. During myelination, synaptic vesicle release from axons promotes sheath stabilization and growth on a subset of neuron subtypes. In comparison, it is unknown if pre-myelinating oligodendrocyte process extensions selectively interact with specific neural circuits or axon subtypes, and whether the formation and stabilization of these neuron-glia interactions involves synaptic vesicle release. In this study, we used fluorescent reporters in the larval zebrafish model to track pre-myelinating oligodendrocyte process extensions interacting with spinal axons utilizing in vivo imaging. Monitoring motile oligodendrocyte processes and their interactions with individually labeled axons revealed that synaptic vesicle release regulates the behavior of subsets of process extensions. Specifically, blocking synaptic vesicle release decreased the longevity of oligodendrocyte process extensions interacting with reticulospinal axons. Furthermore, blocking synaptic vesicle release increased the frequency that new interactions formed and retracted. In contrast, tracking the movements of all process extensions of singly-labeled oligodendrocytes revealed that synaptic vesicle release does not regulate overall process motility or exploratory behavior. Blocking synaptic vesicle release influenced the density of oligodendrocyte process extensions interacting with reticulospinal and serotonergic axons, but not commissural interneuron or dopaminergic axons. Taken together, these data indicate that alterations to synaptic vesicle release cause changes to oligodendrocyte-axon interactions that are neuron subtype specific.
摘要：
少突胶质细胞谱系细胞是中枢神经系统(CNS)神经胶质,其执行多种功能,包括一些但不是所有轴突的选择性髓鞘形成。在髓鞘形成期间,从轴突释放的突触小泡促进鞘的稳定和生长的神经元亚型的子集。相比之下,尚不清楚髓鞘化前少突胶质细胞过程延伸是否与特定的神经回路或轴突亚型有选择性地相互作用，以及这些神经元-神经胶质相互作用的形成和稳定是否涉及突触小泡的释放。在这项研究中,我们在幼体斑马鱼模型中使用荧光报告基因,利用体内成像技术追踪与脊髓轴突相互作用的前髓鞘形成少突胶质细胞过程延伸.监测活动的少突胶质细胞过程及其与单独标记的轴突的相互作用表明，突触小泡的释放调节了过程扩展子集的行为。具体来说,阻断突触小泡的释放降低了少突胶质细胞过程延伸与网状脊髓轴突相互作用的寿命。此外，阻断突触小泡的释放增加了新的相互作用形成和收缩的频率。相比之下,追踪单标记少突胶质细胞的所有过程延伸的运动表明,突触小泡的释放并不调节整个过程的运动性或探索行为.阻断突触小泡的释放影响了少突胶质细胞过程的延伸与网状脊髓和5-羟色胺能轴突相互作用的密度，但不是连合中间神经元或多巴胺能轴突。一起来看,这些数据表明,突触囊泡释放的改变导致少突胶质细胞-轴突相互作用的改变,这是神经元亚型特异性的.
