Heikkinen Anne, Pihlajaniemi Taina, Faissner Andreas, Yuzaki Michisuke
Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.
Department of Cell Morphology and Molecular Neurobiology, Ruhr-University, Bochum, Germany.
Prog Brain Res. 2014;214:29-51. doi: 10.1016/B978-0-444-63486-3.00002-5.
Chemical synapses allow neurons to perform complex computations and regulate other systems of the body. At a chemical synapse, pre- and postsynaptic sites are separated by a small space (the synaptic cleft) and surrounded by astrocytes. The basement membrane (BM), a sheetlike, specialized extracellular matrix (ECM), is found ubiquitously in the PNS. It has become clear that the ECMs not only play a structural role but also serve as barriers and filters in the PNS and CNS. Moreover, proteoglycans and tenascin family proteins in the ECM regulate synapse formation and synaptic plasticity. Although CNS synapses lack the BMs, recent results indicate that the BM-associated collagens are also present in the CNS synaptic cleft and affect synaptogenesis in both the CNS and the PNS. The C1q domain-containing family proteins are important components of the CNS synaptic cleft in regulating synapse formation, maintenance, and the pruning process. The ECM is regarded as a crucial component of the tetrapartite synapse, consisting of pre- and postsynaptic neurons, astrocyte, and ECM.
化学突触使神经元能够进行复杂的计算并调节身体的其他系统。在化学突触处，突触前和突触后位点被一个小空间（突触间隙）隔开，并被星形胶质细胞包围。基底膜（BM）是一种片状的特殊细胞外基质（ECM），在周围神经系统（PNS）中普遍存在。现在已经清楚，细胞外基质不仅起结构作用，而且在周围神经系统和中枢神经系统（CNS）中还充当屏障和过滤器。此外，细胞外基质中的蛋白聚糖和腱生蛋白家族蛋白调节突触形成和突触可塑性。虽然中枢神经系统突触缺乏基底膜，但最近的研究结果表明，与基底膜相关的胶原蛋白也存在于中枢神经系统的突触间隙中，并影响中枢神经系统和周围神经系统的突触发生。含C1q结构域的家族蛋白是中枢神经系统突触间隙中调节突触形成、维持和修剪过程的重要组成部分。细胞外基质被认为是由突触前和突触后神经元、星形胶质细胞和细胞外基质组成的四联体突触的关键组成部分。
