title: Actin Aggregations Mark the Sites of Neurite Initiation.
abstract: A salient feature of neurons is their intrinsic ability to grow and extend neurites, even in the absence of external cues. Compared to the later stages of neuronal development, such as neuronal polarization and dendrite morphogenesis, the early steps of neuritogenesis remain relatively unexplored. Here we showed that redistribution of cortical actin into large aggregates preceded neuritogenesis and determined the site of neurite initiation. Enhancing actin polymerization by jasplakinolide treatment effectively blocked actin redistribution and neurite initiation, while treatment with the actin depolymerizing agents latrunculin A or cytochalasin D accelerated neurite formation. Together, these results demonstrate a critical role of actin dynamics and reorganization in neurite initiation. Further experiments showed that microtubule dynamics and protein synthesis are not required for neurite initiation, but are required for later neurite stabilization. The redistribution of actin during early neuronal development was also observed in the cerebral cortex and hippocampus in vivo.
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Shu-Xin
authors.initials: SX
authors.lastname: Zhang
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Li-Hui
authors.initials: LH
authors.lastname: Duan
authors.affiliation: Department of Applied Mathematics, University of Washington, Seattle, Washington, 98195, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Qian
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China. yuxiang@ion.ac.cn.
authors.forename: Xiang
authors.initials: X
authors.lastname: Yu
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D006624:Hippocampus / Q000254:growth & development; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D016501:Neurites / Q000502:physiology* / Q000648:ultrastructure*; D055495:Neurogenesis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000199:Actins
keywords: Actin; Actin aggregations; Microtubules; Neurite initiation; Neuritogenesis