SHOCK-INDUCED ANALGESIA ON THE FORMALIN TEST - EFFECTS OF SHOCK SEVERITY, NALOXONE, HYPOPHYSECTOMY, AND ASSOCIATIVE VARIABLES
SHOCK-INDUCED ANALGESIA ON THE FORMALIN TEST - EFFECTS OF SHOCK SEVERITY, NALOXONE, HYPOPHYSECTOMY, AND ASSOCIATIVE VARIABLES
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DOI：
10.1037/0735-7044.98.1.79
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发表时间：
1984-01-01
影响因子：
1.9
通讯作者：
FANSELOW, MS
中科院分区：
文献类型：
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作者：
FANSELOW, MS
大鼠暴露于3次电击，间隔20 s，在2个不同的严重程度，低（0.75 s，1 mA）和高（3 s，4 mA）。两种电击水平对大鼠后爪注射福尔马林引起的恢复行为产生了类似的抑制。纳洛酮完全逆转了低严重度休克产生的镇痛作用，但仅部分逆转了高严重度休克产生的镇痛作用（实验1）。垂体切除术没有改变镇痛水平（实验2）。 当大鼠在与它们被电击的房间不同的房间中进行测试时，两个大脑皮层都被完全逆转（实验3）。在休克和镇痛测试之间施加延迟并没有减少镇痛（实验4）。显然，镇痛不是由休克直接引起的，而是由与休克有关的器官刺激引起的。当发现巴甫洛夫消光程序可以完全消除痛觉缺失时，这一立场得到了进一步的支持（实验5）。在所有的实验中，冻结反应，老鼠的物种特异性防御反应之一，与恢复行为同时监测。镇痛和这种防御反应之间存在平行关系，这一结果表明动物的内源性镇痛系统可能与动物的防御动机系统沿着被激活。结果表明，在内源性镇痛系统的控制关联变量的关键性质。他们还表明，休克的严重程度是阿托伐他汀对纳洛酮敏感性的决定因素。
Rats were exposed to 3 shocks, spaced 20 s apart, at 2 different levels of severity, low (.75 s, 1 mA) and high (3 s, 4 mA). Both shock levels produced a similar suppression of the recuperative behavior elicited by an injection of formalin into a rat''s hind paw. Naloxone fully reversed the analgesia produced by the low-severity shock but only partially reversed the analgesia produced by the high-severity shock (experiment 1). Hypophysectomy did not alter the level of analgesia (experiment 2). When the rats were tested in chamber different from the one they were shocked in, both analgesias were totally reversed (experiment 3). Imposing a delay between shock and analgesia testing did not reduce analgesia (experiment 4). Apparently analgesia is not directly elicited by the shock but by apparatus stimuli associated with shock. Further support for this position was obtained when it was found that a Pavlovian extinction procedure could completely eliminate analgesia (experiment 5). In all of the experiments, the freezing response, one of the rat''s species-specific defense reactions, was monitored simultaneously with recuperative behavior. A parallel was found between analgesia and this defensive response, a result suggesting that an animal''s endogenous analgesic systems may be activated along with the animal''s defensive motivational system. The results point to the critical nature of associative variables in the control of endogenous analgesic systems. They also suggest that shock severity is a determinant of analgesia''s sensitivity to naloxone.