Glia-derived signals induce synapse formation in neurones of the rat central nervous system
Glia-derived signals induce synapse formation in neurones of the rat central nervous system
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DOI：
10.1111/j.1469-7793.2001.00665.x
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发表时间：
2001-06-15
影响因子：
5.5
通讯作者：
Pfrieger, FW
中科院分区：
文献类型：
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作者：
Nägler, K;Mauch, DH;Pfrieger, FW
1.为了研究胶质细胞对突触形成的影响，我们建立了纯化的大鼠视网膜神经节细胞（RGC）的微培养物，并使用电生理记录、FM 1 -43标记和免疫细胞化学方法监测单个神经元中突触（autapse）的发育。2.在无神经胶质细胞的条件下，单独培养的神经元在限定培养基中培养2周后，可长出分枝状突起，但仅形成很少且低效的兴奋性自突触.用胶质细胞条件培养基（GCM）处理RGCs的无胶质细胞微培养物可使每个神经元的autapses数量增加10倍。这是由自发事件的频率和FM 1 -43标记的功能释放位点和突触前和突触后标记物共定位的斑点的数量的类似增加指示的。此外，GCM处理增强了突触前递质释放的功效，如刺激诱导的兴奋性自适应电流的失败率较低，异步释放频率增加200倍，刺激诱导的FM 1 -43褪色加速。此外，GCM诱导量子尺寸的增加. GCM对自适应活动的影响不是立即的，而是有24 h的延迟，并且对刺激诱导的自适应电流的影响发生在自发事件频率变化之前，表明早期加强现有的自适应，随后增加自适应数量。所观察到的效应是由GCM中的蛋白酶K敏感因子介导的，并且独立于电活动发生。这些结果表明，可溶性胶质源性信号诱导突触的形成和成熟的神经元的中枢神经系统（CNS）。
1. To study the effects of glial cells on synapse formation, we established microcultures of purified rat retinal ganglion cells (RGCs) and monitored synapse (autapse) development in single neurones using electrophysiological recordings, FM1-43 labelling and immunocytochemistry.2. Solitary neurones grew ramifying neurites, but formed only very few and inefficient excitatory autapses, when cultured for up to 2 weeks in defined medium and in the absence of glial cells.3. Treatment of glia-free microcultures of RGCs with glia-conditioned medium (GCM) increased the number of autapses per neurone by up to 10-fold. This was indicated by a similar increase in the frequency of spontaneous events and the number of FM1-43-labelled functional release sites and of puncta, where pre- and postsynaptic markers colocalized.4. In addition, GCM treatment enhanced the efficacy of presynaptic transmitter release as indicated by lower failure rates of stimulation-induced excitatory autaptic currents, a 200-fold increase in the frequency of asynchronous release and an accelerated stimulation-induced FM1-43 destaining. Furthermore, GCM induced an increase in the quantal size.5. GCM affected autaptic activity not immediately, but with a delay of 24 h, and the effects on stimulation-induced autaptic currents occurred before changes in the frequency of spontaneous events indicating an early strengthening of existing autapses followed by a later increase in autapse number.6. The observed effects were mediated by proteinase K-sensitive factors in GCM and occurred independently of electrical activity.7. These results suggest that soluble glia-derived signals induce synapse formation and maturation in neurones of the central nervous system (CNS).