Buffelli Mario, Burgess Robert W, Feng Guoping, Lobe Corrinne G, Lichtman Jeff W, Sanes Joshua R
Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid, St Louis, Missouri 63110, USA.
Nature. 2003 Jul 24;424(6947):430-4. doi: 10.1038/nature01844.
Synaptic activity drives synaptic rearrangement in the vertebrate nervous system; indeed, this appears to be a main way in which experience shapes neural connectivity. One rearrangement that occurs in many parts of the nervous system during early postnatal life is a competitive process called 'synapse elimination'. At the neuromuscular junction, where synapse elimination has been analysed in detail, muscle fibres are initially innervated by multiple axons, then all but one are withdrawn and the 'winner' enlarges. In support of the idea that synapse elimination is activity dependent, it is slowed or speeded when total neuromuscular activity is decreased or increased, respectively. However, most hypotheses about synaptic rearrangement postulate that change depends less on total activity than on the relative activity of the competitors. Intuitively, it seems that the input best able to excite its postsynaptic target would be most likely to win the competition, but some theories and results make other predictions. Here we use a genetic method to selectively inhibit neurotransmission from one of two inputs to a single target cell. We show that more powerful inputs are strongly favoured competitors during synapse elimination.
突触活动驱动脊椎动物神经系统中的突触重排；事实上，这似乎是经验塑造神经连接的主要方式之一。在出生后早期，神经系统许多部位都会发生一种名为“突触消除”的竞争性重排过程。在神经肌肉接头处，突触消除已得到详细分析，肌肉纤维最初由多条轴突支配，随后除一条轴突外，其余轴突都会撤回，而“获胜”的轴突会增大。为支持突触消除依赖于活动这一观点，当神经肌肉总活动分别减少或增加时，突触消除过程会减缓或加速。然而，大多数关于突触重排的假说认为，变化更多地取决于竞争者之间的相对活动，而非总活动。直观地说，似乎最能兴奋其突触后靶点的输入最有可能在竞争中获胜，但一些理论和结果却做出了其他预测。在这里，我们使用一种基因方法来选择性抑制从两个输入之一到单个靶细胞的神经传递。我们表明，在突触消除过程中，更强有力的输入是极具优势的竞争者。
