Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
Mol Pain. 2010 Jul 23;6:42. doi: 10.1186/1744-8069-6-42.
The anterior cingulate cortex (ACC) and medial thalamus (MT) are two of the main components of the medial pain pathway that subserve the affective aspect of pain. The hypothesis of the present study was that the ACC is involved in short-term aversive information processing and that the MT is critical for encoding unconditioned nociceptive information. The roles of these two components in short-term and long-term aversive information processing was investigated using a step-through inhibitory avoidance task.
Behavioral training began 1 week after surgery, in which radiofrequency lesions of the ACC or MT were performed. The retention tests were conducted 30 s (short-term) or 24 h (long-term) after training. Pretraining radiofrequency lesions of the ACC impaired performance in the 30 s, but not 24 h, retention test. Microinfusions of lidocaine into the ACC immediately after training impaired performance in the retention test conducted 10 min later. Pretraining radiofrequency lesions of the MT impaired performance in both the 30 s and 24 h retention tests. However, posttraining, but not pretest, microinfusions of lidocaine into the MT impaired performance in the 24 h retention test.
These results suggest that the ACC may play an important role in short-term, but not long-term, nociceptive information processing. In contrast, the MT may be important for the consolidation of nociceptive information storage.
前扣带皮层（ACC）和内侧丘脑（MT）是介导疼痛情感方面的内侧疼痛通路的两个主要组成部分。本研究的假设是，ACC 参与短期厌恶信息处理，而 MT 对编码非条件伤害性信息至关重要。使用一步式抑制性回避任务研究了这两个成分在短期和长期厌恶信息处理中的作用。
手术后 1 周开始进行行为训练，对 ACC 或 MT 进行射频损伤。在训练后 30 秒（短期）或 24 小时（长期）进行保留测试。预训练的 ACC 射频损伤会损害 30 秒保留测试的表现，但不会损害 24 小时保留测试的表现。训练后立即将利多卡因微灌注到 ACC 中，会损害 10 分钟后的保留测试表现。预训练的 MT 射频损伤会损害 30 秒和 24 小时保留测试的表现。然而，只有在训练后，而不是在测试前，将利多卡因微灌注到 MT 中，才会损害 24 小时保留测试的表现。
这些结果表明，ACC 可能在短期但非长期伤害性信息处理中发挥重要作用。相比之下，MT 可能对伤害性信息储存的巩固很重要。
