The unconditioned feeding response of the mottled sculpin, Cottus bairdi, was used to measure threshold sensitivity of the lateral line system to a vibrating sphere as a function of stimulus position (i.e., sphere near head, trunk or tail) and vibration frequency. In addition, extracellular recording techniques were used to measure threshold sensitivity curves for posterior lateral line nerve fibers for the same stimulus positions used for measuring trunk sensitivity in behavioral measurements. 2. For all stimulus positions, behaviorally-measured threshold sensitivity was relatively independent of vibration frequency from 10 to 100 Hz when defined in terms of water acceleration, rather than velocity or displacement. Best thresholds for stimuli placed 15 mm away from the head were around -75 dB re: 1m/s(2), approximately 20 dB less than that for stimuli placed at the same distance near the tail. Trunk sensitivity was intermediate. 3. Physiologically-measured threshold sensitivity, in terms of acceleration, was also relatively independent of of frequency from 10 to 100 Hz in most fibers. A smaller number of fibers showed a decline in acceleration sensitivity after 10-30 Hz, with the rate of decline being equivalent to equal velocity sensitivity. Best sensitivity of all fibers fell between -40 and -70 dB re: 1m/s (2). 4. These results indicate that (a) behavioral thresholds are based on acceleration-sensitive endorgans--most likely lateral line canal (rather than superficial) neuromasts, (b) behavioral performance can be accounted for on the basis of information from a single population of fibers, and (c) sensitivity varies along the fish's body in a manner that corresponds to the size and distribution of neuromasts.
摘要
利用斑驳杜父鱼（Cottus bairdi）的非条件摄食反应，来测量侧线系统对振动球体的阈值敏感性，该敏感性是刺激位置（即球体靠近头部、躯干或尾部）和振动频率的函数。此外，使用细胞外记录技术来测量后侧线神经纤维的阈值敏感性曲线，这些曲线对应于行为测量中用于测量躯干敏感性的相同刺激位置。2. 对于所有刺激位置，当根据水加速度而非速度或位移来定义时，行为测量的阈值敏感性在10至100 Hz的振动频率范围内相对独立于频率。置于离头部15毫米处的刺激的最佳阈值约为-75 dB re: 1m/s²，比置于尾部相同距离处的刺激的阈值低约20 dB。躯干敏感性处于中间水平。3. 在大多数纤维中，就加速度而言，生理测量的阈值敏感性在10至100 Hz的频率范围内也相对独立于频率。少数纤维在10 - 30 Hz后加速度敏感性下降，下降速率与等速敏感性相当。所有纤维的最佳敏感性在-40至-70 dB re: 1m/s²之间。4. 这些结果表明：（a）行为阈值基于对加速度敏感的终器——最有可能是侧线管（而非表面）神经丘；（b）行为表现可以根据来自单一纤维群体的信息来解释；（c）敏感性沿鱼体的变化方式与神经丘的大小和分布相对应。
