Joynes R L, Grau J W
Department of Psychology, Texas A&M University, College Station 77843.
Behav Neurosci. 1996 Dec;110(6):1375-87. doi: 10.1037//0735-7044.110.6.1375.
Conditioned antinociception can be established in spinal rats by pairing stimulation to one hind leg (the conditioned stimulus [CS]) with an intense tailshock (the unconditioned stimulus [US]). After this training, the paired CS (CS+) elicits greater antinociception on the tail-flick test than a CS that was explicitly unpaired (CS-). Five experiments are reported that suggest that this effect reflects protection from habituation. Experiment 1 showed that the CS (legshock) induces antinociception before training. Presenting the CS alone weakened (habituated) its antinociceptive impact (Experiment 2). Less habituation was observed when the CS was paired with the US (Experiment 3). Decreasing habituation to the CS- (by increasing the interval between trials) and facilitating habituation to the CS+ (by increasing the number of trials) effectively eliminated the CS+/CS- difference (Experiments 4 and 5).
通过将对一条后腿的刺激（条件刺激[CS]）与强烈的尾部电击（非条件刺激[US]）配对，可在脊髓大鼠中建立条件性抗伤害感受。经过这种训练后，配对的CS（CS+）在甩尾试验中比明确未配对的CS（CS-）引发更强的抗伤害感受。本文报告了五个实验，这些实验表明这种效应反映了对习惯化的保护。实验1表明，CS（腿部电击）在训练前诱导抗伤害感受。单独呈现CS会削弱（使其习惯化）其抗伤害感受的影响（实验2）。当CS与US配对时，观察到的习惯化较少（实验3）。减少对CS-的习惯化（通过增加试验间隔）和促进对CS+的习惯化（通过增加试验次数）有效地消除了CS+/CS-差异（实验4和5）。
