Meagher M W, Grau J W, King R A
Department of Psychology, Texas A&M University, College Station 77843.
Behav Neurosci. 1989 Dec;103(6):1366-71. doi: 10.1037//0735-7044.103.6.1366.
Previous research (Grau, 1987a, 1987b) suggests that forebrain systems play an essential role in the hypoalgesia observed after brief shock but not long shock. Additional research has shown that pentobarbital anesthesia and decerebration block the hypoalgesia observed after 3 brief (0.75-s) shocks but not the hypoalgesia observed after 3 long (25-s) shocks. This is a study of whether a specific forebrain lesion, a frontal cortex lesion, would have a similar impact on hypoalgesia induced by brief (0.75 s) and long (25-s) shocks. Frontal cortex lesions, like decerebration and pentobarbital anesthesia, eliminated the hypoalgesia observed after brief but not long shocks. Because other research suggests that the stress of surgery may influence whether the hypoalgesia elicited by shock is opioid or nonopioid, the 2nd experiment was to examine whether the sham operation per se alters the form of the hypoalgesia observed after brief shock. It does not; in the sham-treated subjects, brief shock induced the usual transient nonopioid hypoalgesia followed by prolonged opioid hypoalgesia. These data suggest that frontal cortex lesions block nonopioid and opioid hypoalgesia observed after brief shock.
先前的研究（格劳，1987年a，1987年b）表明，前脑系统在短暂电击而非长时间电击后观察到的痛觉减退中起重要作用。进一步的研究表明，戊巴比妥麻醉和大脑去皮质术可阻断3次短暂（0.75秒）电击后观察到的痛觉减退，但不能阻断3次长时间（25秒）电击后观察到的痛觉减退。本研究旨在探讨一种特定的前脑损伤，即额叶皮质损伤，是否会对短暂（0.75秒）和长时间（25秒）电击诱导的痛觉减退产生类似影响。与大脑去皮质术和戊巴比妥麻醉一样，额叶皮质损伤消除了短暂电击后观察到的痛觉减退，但未消除长时间电击后观察到的痛觉减退。由于其他研究表明手术应激可能会影响电击引起的痛觉减退是阿片类还是非阿片类，第二个实验是检验假手术本身是否会改变短暂电击后观察到的痛觉减退形式。结果并非如此；在接受假手术的受试者中，短暂电击会诱导通常的短暂非阿片类痛觉减退，随后是持续的阿片类痛觉减退。这些数据表明，额叶皮质损伤会阻断短暂电击后观察到的非阿片类和阿片类痛觉减退。
