Milne Richard J, Gamble Gregory D
Department of Physiology, University of Auckland, Auckland (New Zealand).
Pain. 1989 Oct;39(1):103-107. doi: 10.1016/0304-3959(89)90180-2.
Habituation of rats to the testing environment and procedures reduces flexor withdrawal latencies to those of spinalised animals. We have now recorded surface temperatures at 3 sites on the tail and tail-flick latencies simultaneously in experimentally naive (novice) rats and in habituated rats. At usual ambient temperatures (20 +/- 1 degree C), tail temperatures fluctuated in accordance with the predictions of an on-off controller. There was an inverse correlation between the tail-flick latency and the temperature at the site of noxious stimulation. A similar correlation was found when the pre-stimulus temperature of the tip of the tail was held at temperatures ranging from 21 degrees C to 35 degrees C. Habituated animals exhibited a similar linear regression slope factor but lower latencies than novice animals at each temperature. We conclude (1) that tail-flick latency is determined partly by the pre-stimulus temperature at the site of noxious thermal stimulation, and (2) that the effects of habituation on tail-flick latency are more likely to be explained by differences in nociception than in regional vasomotor tone.
大鼠对测试环境和程序的适应会使屈肌反射潜伏期缩短至脊髓损伤动物的水平。我们现在同时记录了实验未处理（新手）大鼠和适应大鼠尾巴上3个部位的表面温度以及甩尾潜伏期。在通常的环境温度（20±1℃）下，尾巴温度根据开关控制器的预测而波动。甩尾潜伏期与有害刺激部位的温度呈负相关。当尾巴尖端的刺激前温度保持在21℃至35℃范围内时，也发现了类似的相关性。在每个温度下，适应动物表现出相似的线性回归斜率因子，但潜伏期比新手动物短。我们得出结论：（1）甩尾潜伏期部分由有害热刺激部位的刺激前温度决定；（2）适应对甩尾潜伏期的影响更可能是由伤害感受的差异而非局部血管舒缩张力的差异来解释。
