Rapid Dendritic Remodeling in the Developing Retina: Dependence on Neurotransmission and Reciprocal Regulation by Rac and Rho
Rapid Dendritic Remodeling in the Developing Retina: Dependence on Neurotransmission and Reciprocal Regulation by Rac and Rho
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DOI：
10.1523/jneurosci.20-13-05024.2000
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发表时间：
2000-07
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影响因子：
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通讯作者：
Wai T. Wong;B. Faulkner-Jones;J. Sanes;R. Wong
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文献类型：
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作者：
Wai T. Wong;B. Faulkner-Jones;J. Sanes;R. Wong
我们证明，在完整的和自发活动的视网膜，神经节细胞的树突状进程表现出快速和广泛的运动期间的突触。显著的重组发生在几秒钟内，但结构变化在整个树枝状乔木中相对平衡，在几个小时内保持整体乔木的大小和复杂性。树突的运动性受自发性突触传递的调节。NMDA和非NMDA谷氨酸受体拮抗剂降低运动的速率和程度，但不受河豚毒素（一种钠通道阻滞剂）的影响。树突状细胞的运动是肌动蛋白依赖性的，并由Rho家族的小GTP酶控制。显性负性和组成型活性突变体转染神经节细胞表明，Rac和Rho发挥相互作用的运动。我们认为，Rho家族的小GTP酶可以整合活动依赖性和独立的传入信号，从而调整目标的运动性和最大限度地提高初始接触和随后的突触发生的机会。
We demonstrate that within the intact and spontaneously active retina, dendritic processes of ganglion cells exhibit rapid and extensive movements during the period of synaptogenesis. Marked restructuring occurs in seconds, but structural changes are relatively balanced across the dendritic arbor, maintaining overall arbor size and complexity over hours. Dendritic motility is regulated by spontaneous glutamatergic transmission. Both the rate and extent of the movements are decreased by antagonists to NMDA and non-NMDA glutamate receptors but are unaffected by tetrodotoxin, a sodium channel blocker. The dendritic movements are actin dependent and are controlled by the Rho family of small GTPases. Transfection of dominant-negative and constitutively active mutants into ganglion cells showed that Rac and Rho exert reciprocal effects on motility. We suggest that the Rho family of small GTPases could integrate activity-dependent and -independent signals from afferents, thereby adjusting target motility and maximizing the chance for initial contact and subsequent synaptogenesis.