Lohmann Christian, Bonhoeffer Tobias
Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany.
Neuron. 2008 Jul 31;59(2):253-60. doi: 10.1016/j.neuron.2008.05.025.
Synapse elimination is an important process underlying the establishment of functional neuronal networks during development. Here, we tested the idea that neurons select among potential synaptic partners already during initial contact formation between dendritic filopodia and axons-well before mature synapses are established. We show that filopodia frequently make contact with axons, and while some contacts are selectively stabilized, many are short-lived. More specifically, we demonstrate that contacts with a certain population of GABAergic axons never get stabilized, indicating that filopodia already early on select between different types of axons. Local dendritic calcium transients that are independent of glutamate occur within seconds after contact formation, and their frequency is high where contacts become stabilized and low at short-lived contacts. Thus, filopodia are capable of choosing between potential synaptic partners well before a mature synapse is established.
突触消除是发育过程中功能性神经网络建立的重要基础过程。在此，我们测试了一种观点，即神经元在树突丝状伪足与轴突最初形成接触时——远在成熟突触建立之前——就已经在潜在的突触伙伴之间进行选择。我们发现丝状伪足经常与轴突接触，虽然一些接触会被选择性地稳定下来，但许多接触是短暂的。更具体地说，我们证明与特定群体的GABA能轴突的接触从未稳定下来，这表明丝状伪足在早期就已经在不同类型的轴突之间进行选择。独立于谷氨酸的局部树突钙瞬变在接触形成后几秒钟内就会出现，其频率在接触稳定的地方较高，而在短暂接触处较低。因此，丝状伪足在成熟突触建立之前就能在潜在的突触伙伴之间进行选择。
