Activity-independent specification of synaptic targets in the posterior lateral line of the larval zebrafish
Activity-independent specification of synaptic targets in the posterior lateral line of the larval zebrafish
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DOI：
10.1073/pnas.0912082106
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发表时间：
2009-12-22
影响因子：
11.1
通讯作者：
Hudspeth, A. J.
中科院分区：
文献类型：
--
作者：
Nagiel, Aaron;Patel, Suchit H.;Hudspeth, A. J.
功能性神经回路的发展需要以精确的方式建立神经元之间的连接。复杂的神经系统执行这项艰巨任务的机制在很大程度上仍然未知。在斑马鱼幼鱼的后侧线中，每个传入神经元与具有共同毛束极性的毛细胞形成突触接触。我们研究传入神经元是否区分毛细胞极性，通过分析相反极化的毛细胞之间的突触信号的差异。通过研究两个突变的斑马鱼线与缺陷的机械电转导，并通过阻断野生型鱼的发展过程中的转导，我们发现，传入神经元可以形成特定的突触刺激诱发的突触释放模式的情况下。接下来，我们询问这种特异性是否是通过突触释放的固有模式产生的，我们发现，极性偏好在两个缺乏必需突触蛋白的突变株系中持续存在。这些结果表明，侧线传入神经元不需要突触活动来区分毛细胞的极性，并建议毛细胞极性的分子标签引导预图案化的传入形成适当的突触。
The development of functional neural circuits requires that connections between neurons be established in a precise manner. The mechanisms by which complex nervous systems perform this daunting task remain largely unknown. In the posterior lateral line of larval zebrafish, each afferent neuron forms synaptic contacts with hair cells of a common hair-bundle polarity. We investigated whether afferent neurons distinguish hair-cell polarities by analyzing differences in the synaptic signaling between oppositely polarized hair cells. By examining two mutant zebrafish lines with defects in mechanoelectrical transduction, and by blocking transduction during the development of wild-type fish, we found that afferent neurons could form specific synapses in the absence of stimulus-evoked patterns of synaptic release. Asking next whether this specificity arises through intrinsically generated patterns of synaptic release, we found that the polarity preference persisted in two mutant lines lacking essential synaptic proteins. These results indicate that lateral-line afferent neurons do not require synaptic activity to distinguish hair-cell polarities and suggest that molecular labels of hair-cell polarity guide prepatterned afferents to form the appropriate synapses.