King T E, Joynes R L, Grau J W
Department of Psychology, Texas A&M University, College Station 77843, USA.
Behav Neurosci. 1997 Aug;111(4):754-67. doi: 10.1037//0735-7044.111.4.754.
It is held that the tail-flick test of pain depends on a spinal reflex because a similar response is observed in spinally transected rats. But when subjects were manually held and a cool heat setting was used, supraspinal systems facilitated the response (Experiment 1). This effect did not depend on the rate at which the tail was heated (Experiment 2) but rather on the co-occurrence of visual, auditory, and tactile cues that predict impending pain (Experiments 3 and 4). Subjects rapidly learned to exhibit a tail movement during these co-occurring cues, and this avoidance response was instrumental in nature (Experiment 5). Optimal learning was observed when the visual signal was presented 8-12 s before a heat-elicited response is normally observed (Experiment 6), and a low dose of morphine inhibited the performance of the instrumental response (Experiment 7).
人们认为，疼痛的甩尾测试依赖于脊髓反射，因为在脊髓横断的大鼠中观察到了类似的反应。但是，当手动握住受试者并使用冷热设置时，脊髓上系统促进了这种反应（实验1）。这种效应不取决于尾巴受热的速率（实验2），而是取决于预测即将到来的疼痛的视觉、听觉和触觉线索的共同出现（实验3和4）。受试者在这些共同出现的线索期间迅速学会表现出尾巴运动，并且这种回避反应本质上是工具性的（实验5）。当视觉信号在通常观察到热诱发反应之前8-12秒呈现时，观察到最佳学习效果（实验6），低剂量吗啡抑制了工具性反应的表现（实验7）。
