Activity-dependent regulation of the expression of chondroitin sulfate proteoglycan and neuronal plasticity

硫酸软骨素蛋白聚糖（CSPG）是一种以共价键连接硫酸化糖胺聚糖链的糖蛋白，其核心蛋白的一级结构已被阐明30多种。CSPG是中枢神经系统细胞外基质的主要成分。本研究的主要结果如下：1）磷酸蛋白聚糖的水平以活性依赖的方式调节，这种下调是通过tPA作用介导的蛋白水解而实现的; 2）磷酸蛋白聚糖定位于平行纤维轴突膜的分子层，抑制颗粒细胞的粘附和伸展，促进平行纤维的成束。培养的皮层神经元能够在无胶质细胞的情况下构建神经元周网状结构。这一结果表明，神经束膜网是神经元起源的。

Chondroitin sulfate proteoglycans (CSPGs) are glycoproteins that carry covalently bound sulfated glycosaminoglycan chains, and more than 30 primary structures of core proteins have been elucidated. CSPGs are main components of extracellular matrix in the central nervous system. The present research program demonstrated following main results.1) The levels of phosphacan proteoglycan was regulated with activity-dependent manner and this downregulation was mediated via proteolysis by tPA action.2) Phosphacan was localized at axonal membrane of parallel fibers in the molecular layer and inhibited adhesion and extension of granule cells and promoted the fasciculation of parallel fibers.3) Cultured cortical neurons were able to construct perineuronal net-like structure without glial cells. This result indicate that perineuronal net is neuronal origin.