树突是神经元信息传递和整合的关键结构，树突发育对于神经环路的形成及可塑性至关重要。CRMP-2与树突发育关系密切。我们发现，CRMP-2特异性定位于小脑颗粒神经元的树突并调控其生长，但机制有待阐明。前期的预实验结果表明，Plexin-A3与CRMP-2的分布具有高度一致性，而且过表达Plexin-A3能够促进树突发育，GST-pulldown及免疫共沉淀的结果显示Plexin-A3能与CRMP-2相互作用，提示二者可能通过相互作用共同调控神经元的树突发育。本研究拟进一步通过体外细胞培养及小脑脑片培养等模型，明确Plexin-A3对树突发育的影响，获得CRMP-2与Plexin-A3直接相互作用并调控神经元树突发育的证据。本项目有望揭示CRMP-2调控树突发育的新机制，有助于解析发育相关神经系统疾病的神经基础，为临床治疗相关疾病提供切实的科学依据及新的思路。

Dendrite is the critical structure for neuronal synaptic transmission and information integration. Dendrite development is important for neuronal circuit formation and plasticity. CRMP-2 is reported to be closely related to dendrite development. Our former research revealed that CRMP-2 was specifically located at dendrites but not axons in cerebellar granule neurons, and regulated activity-dependent dendrite growth. However, the mechanisms remained to be further elucidated. Our data further confirmation that Plexin-A3 also located in dendrites, the same as CRMP-2. Overexpression of Plexin-A3 promoted dendrite growth and GST-pulldown/immunoprecipitation showed that Plexin-A3 could interact with CRMP-2, , suggesting the direct interaction of these two proteins to regulate dendrite growth together. By pulldown experiment, immunoprecipitation, immunofluorescence, overexpression and siRNA experiment, this study will determine the impact of Plexin-A3 on dendrite development, get the evidence of direct interaction between CRMP-2 and Plexin-A3 and elucidate the mechanism of CRMP-2/Plexin-A3 interaction regulated dendrite growth. This study will reveal a new mechanism of CRMP-2 regulated dendrite development, help to further understand the neuronal basics of developmental related neuronal diseases and provide theoretical basis and new insight for clinical treatment.