Gan W B, Lichtman J W
Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, Box 8108, St. Louis, MO 63110, USA.
Science. 1998 Nov 20;282(5393):1508-11. doi: 10.1126/science.282.5393.1508.
Throughout the developing nervous system, competition between axons causes the permanent removal of some synaptic connections. In mouse neuromuscular junctions at birth, terminal branches of different axons are intermingled. However, during the several weeks after birth, these branches progressively segregated into nonoverlapping compartments before the complete withdrawal of all but one axon. Segregation was caused by selective branch atrophy, detachment, and withdrawal; the axon branches that were nearest to the competitor's branches were removed before the more distant branches were removed. This progression suggests that the signals that mediate the competitive removal of synapses must decrease in potency over short distances.
在整个发育中的神经系统中，轴突之间的竞争会导致一些突触连接被永久性去除。在出生时的小鼠神经肌肉接头处，不同轴突的终末分支相互交织。然而，在出生后的几周内，这些分支会逐渐分离成不重叠的区域，直到除了一根轴突之外的所有轴突完全撤回。分离是由选择性分支萎缩、脱离和撤回引起的；最靠近竞争轴突分支的轴突分支会在距离较远的分支被去除之前被去除。这种进展表明，介导突触竞争性去除的信号在短距离内的效力必然会降低。
