Temporal constraints on visually directed C-start responses: Behavioral and physiological correlates
Temporal constraints on visually directed C-start responses: Behavioral and physiological correlates
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DOI：
10.1159/000069751
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发表时间：
2003-01-01
影响因子：
1.7
通讯作者：
Canfield, JG
中科院分区：
文献类型：
--
作者：
Canfield, JG
为了研究视觉信息对Mauthner（M-）启动的C-start反应的调节作用，在用声脉冲惊吓前，向个体慈鲷鱼提供短间隔视觉刺激。由于每个毛特纳神经元的轴突激活索马对侧的躯干肌肉组织，因此随后的惊吓反应的初始方向提供了一种行为测量，即当声音脉冲导致一个细胞放电时，哪个细胞已经被视觉线索驱动接近阈值。当一个LED灯在鱼的一侧照亮10毫秒，然后发出惊人的声音脉冲，慈鲷可靠地转向视觉线索。在15和20毫秒的持续时间，鱼转身离开相同的刺激。因此，行为证据表明，M细胞对侧的视觉刺激似乎是兴奋的第一，但视觉刺激的同侧的M细胞的视觉兴奋其次，并占主导地位。与行为结果一致，在慈鲷M细胞中细胞内记录的视觉诱发兴奋电位是复杂的，初始PSP显示对侧眼刺激的延迟约为11.6 ms，刺激同侧眼的延迟约为15.5 ms。金鱼的PSP潜伏期更长，更相似的刺激的两个眼睛（约22 ms）。相比之下，声音诱发的PSP开始在2毫秒内。视觉调节M细胞功能的相对较长的潜伏期表明，视觉是最适应的偏置响应方向之前，而不是在捕食者的攻击。
To study the modulatory influences of visual information on Mauthner (M-) initiated C-start responses, short interval visual stimuli were presented to individual cichlid fish prior to being startled with a sound pulse. Because the axon of each Mauthner neuron activates trunk musculature contralateral to the soma, the initial direction of an ensuing startle response provides a behavioral measure of which cell has been driven closer to threshold by visual cues at the time the sound pulse causes one cell to fire. When an LED was illuminated on one side of the fish for 10 ms prior to a startling sound pulse, cichlids reliably turned toward the visual cue. At durations of 15 and 20 ms, fish turned away from the same stimulus. Thus, behavioral evidence suggests that the M-cell contralateral to a visual stimulus appears to be excited first but visual excitation of the M-cell ipsilateral to the visual stimulus follows and predominates. Consistent with the behavioral results, visually evoked excitatory potentials recorded intracellularly in the cichlid M-cells were complex, with initial PSPs showing latencies of about 11.6 ms from contralateral eye stimulation and 15.5 ms from stimulating the ipsilateral eye. PSP latencies in goldfish were longer and more similar for stimuli to the two eyes (about 22 ms). For contrast, sound-evoked PSPs begin within 2 ms. The relative long latencies for visually regulating M-cell function suggest that vision is most adaptive for biasing response direction prior to rather than during a predator's attack.