S- and C-start escape responses of the muskellunge (Esox masquinongy) require alternative neuromotor mechanisms.
S- and C-start escape responses of the muskellunge (Esox masquinongy) require alternative neuromotor mechanisms.
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发表时间：
2002-07
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通讯作者：
Melina E. Hale
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作者：
Melina E. Hale
惊吓反应是一种用于检查行为神经基础的模型系统，因为它的神经回路组织和运动模式相对简单。在鱼类中，两种主要的惊吓行为在它们的初始运动中是不同的。在C形启动类型的惊吓中，鱼弯曲成C形，而S形启动涉及S形身体弯曲。虽然相当多的研究集中在确定C-启动是如何产生的神经，S-启动神经生物学还没有被检查。我量化的运动学和肌电图模式的初始动作的C-开始和S-开始的muskellunge（Esox masquinongy）的行为，以测试三个假设如何产生的S-开始。(i)S型启动与C型启动是由相同的运动神经回路产生的，但尾巴的被动弯曲会导致身体呈现S形。(ii)S-启动是由与波动游泳相同的运动神经回路产生的。(iii)S-启动是由一个独立的神经机制，无论是在C-启动或波动游泳。运动学和肌肉活动模式的结果支持第三个假设。在麝香龙中，S启动是一种高性能的惊吓行为，其初始弯曲的峰值角速度和峰值角加速度与C启动的峰值角速度和峰值角加速度相当，并且高于波动游泳的预期。然而，S-开始运动模式与C-开始运动模式不同，S-开始运动模式在身体一侧的前部和相对侧的后部同时具有肌肉活动。相反，C型起始的特征是沿着身体的全长沿着同时进行单侧肌肉活动。替代模型提出了S-开始神经回路组织涉及网状脊髓和局部控制肌肉活动。
The startle response is a model system for examining the neural basis of behavior because of its relatively simple neural circuit organization and kinematic pattern. In fishes, the two primary types of startle behavior differ in their initial movements. In the C-start type of startle, the fish bends into a C shape, while the S-start involves an S-shaped body bend. Although considerable research has focused on determining how the C-start is generated neurally, S-start neurobiology has not been examined. I quantify the kinematics and electromyographic patterns of the initial movements of the C-start and S-start behaviors of the muskellunge (Esox masquinongy) to test three hypotheses for how the S-start is generated. (i) The S-start is generated by the same motor neural circuit as the C-start, but passive bending of the tail causes the body to take on an S shape. (ii) The S-start is generated by the same motor neural circuit as undulatory swimming. (iii) The S-start is generated by an independent neural mechanism from that used either in the C-start or in undulatory swimming. Results from kinematics and muscle activity patterns support the third hypothesis. In the muskellunge, the S-start is a high-performance startle behavior with peak angular velocity and peak angular acceleration of its initial bending comparable with those of the C-start and higher than would be expected for undulatory swimming. The S-start motor pattern, however, is distinct from the C-start motor pattern in having simultaneous muscle activity anteriorly on one side of the body and posteriorly on the opposite side. In contrast, the C-start is characterized by simultaneous unilateral muscle activity along the full length of the body. Alternative models are proposed for S-start neural circuit organization involving reticulospinal and local control of muscle activity.