Episodic swimming in the larval zebrafish is generated by a spatially distributed spinal network with modular functional organization.
Episodic swimming in the larval zebrafish is generated by a spatially distributed spinal network with modular functional organization.
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DOI：
10.1152/jn.00233.2012
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发表时间：
2012-08
影响因子：
2.5
通讯作者：
T. Wiggin;Tatiana M. Anderson;J. Eian;Jack Peck;M. A. Masino
中科院分区：
文献类型：
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作者：
T. Wiggin;Tatiana M. Anderson;J. Eian;Jack Peck;M. A. Masino
尽管脊椎动物用于运动的方法多种多样，但有证据表明，运动中枢模式发生器（CPG）的组成部分在物种间是保守的。当斑马鱼在发育的早期开始游泳时，它们会进行短暂的活动，这些活动被不活动的时期隔开。在这些事件中，躯干弯曲与侧到侧的交替和旅行体波的进展喙尾。为了表征游泳CPG沿着吻尾轴的分布，我们进行了斑马鱼幼鱼脊髓横断和诱导虚构的游泳用N-甲基-d-天冬氨酸（NMDA）。在完整的和spinalized幼虫，爆裂被发现在整个rostrocaudal程度的脊髓，和虚拟游泳观察到的属性是依赖于NMDA的浓度。我们通过对同一幼虫进行多次脊髓横断来分离一系列连续的脊髓节段。尽管来自脊髓所有区域的序列都有产生爆发的能力，但产生有组织的虚构游泳片段的能力具有吻侧偏好：在吻侧脊髓中，仅需要12个连续的身体节段，而在尾侧脊髓中，需要23个连续的身体节段。较短的一系列节段往往是活跃的，但产生连续的节奏爆发或零星的，非节奏的爆发。这两个情节和连续的爆发交替之间的左侧和右侧的身体，并显示rostrocaudal进展，表明功能分离的电路负责情节结构和精细的突发时间。这些发现平行的结果在哺乳动物的运动，我们提出了一个层次模型的幼斑马鱼游泳CPG。
Despite the diverse methods vertebrates use for locomotion, there is evidence that components of the locomotor central pattern generator (CPG) are conserved across species. When zebrafish begin swimming early in development, they perform short episodes of activity separated by periods of inactivity. Within these episodes, the trunk flexes with side-to-side alternation and the traveling body wave progresses rostrocaudally. To characterize the distribution of the swimming CPG along the rostrocaudal axis, we performed transections of the larval zebrafish spinal cord and induced fictive swimming using N-methyl-d-aspartate (NMDA). In both intact and spinalized larvae, bursting is found throughout the rostrocaudal extent of the spinal cord, and the properties of fictive swimming observed were dependent on the concentration of NMDA. We isolated series of contiguous spinal segments by performing multiple spinal transections on the same larvae. Although series from all regions of the spinal cord have the capacity to produce bursts, the capacity to produce organized episodes of fictive swimming has a rostral bias: in the rostral spinal cord, only 12 contiguous body segments are necessary, whereas 23 contiguous body segments are necessary in the caudal spinal cord. Shorter series of segments were often active but produced either continuous rhythmic bursting or sporadic, nonrhythmic bursting. Both episodic and continuous bursting alternated between the left and right sides of the body and showed rostrocaudal progression, demonstrating the functional dissociation of the circuits responsible for episodic structure and fine burst timing. These findings parallel results in mammalian locomotion, and we propose a hierarchical model of the larval zebrafish swimming CPG.